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Repairing inverters...

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Hi.
Perhaps the wrong forum section for the subject; but can be dangerous for many without proper procedures and servicing instructions.
Do service manuals exist or are they plainly unobtanium for the many brands / models on the market ?
At least; if no schematics are available to the public; do helpful block diagrams of inverters exist ? Nothing wrong with protecting copyright circuitry and patents; but do 'authorized' service centers have access to repair information, upgrades, proper parts ?

Do you know of any published repair /service / upgrade / troubleshooting / schematics somewhere; current or obsolete ?

Is it safe to assume H6 (as in Delta/Tesla inverters) is a topology and not just a lettersoup model from manufacturer ?
----> http://www.ijatir.org/uploads/143526IJATIR5952-210.pdf

-Please move if deserved-
 
I am afraid full service manuals or factory spare parts for anything these days are just not available.
Many reasons for that.

The first is that if you spend a lot of money developing a new product over say two years of R&D, and then try to sell it, you will find that within a few weeks, some Chinese company are advertising an identical clone at a price you cannot compete with, and you go out of business.
The Chinese even do it to each other.
So what you do is try to make your new product as difficult to copy as possible, by deliberately trying to hide how it works.

Writing a detailed service manual in twelve different languages with all the pictures and drawings requires highly competant technical people, and its expensive to produce and print. As your product may only have a commercial lifetime of a few months, before the next model is produced, its just not cost effective, as the product has PLANNED OBSOLESCENCE anyway.

For the same reasons, no spare parts are warehoused for previous obsolete models. Its also not cost effective for even the manufacturer to repair warranty returns these days. If it fails in service, within the warranty period, get some minimum wage slave to check fuses, and that the battery is o/k, and if its not some obvious problem, just trash it, and give the customer a brand new unit.
I have worked for a company that did exactly that.

Why pay someone $20/hour to spend an afternoon fixing something only worth $40 ($200 retail to the customer).

And on it goes. Its cheaper to just churn out the stuff in China and the eventual customer be damned.
Its the highest form of consumer capitalism.
Only money matters.
 
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Why pay someone $20/hour to spend an afternoon fixing something ....... I got more than that 40 years ago!

If you have to ask how to fix something, you probably can't even if there was a manual available.
 
Some people are lucky to earn that much even today, believe it or not, even in first world countries.

Back in ancient times components were large enough to have values or at least a colour code printed on them, and component designators printed on the circuit board. Circuit boards only had one or at most two layers, and tracks could be easily followed, and with patience the entire circuit traced out.
No secret software or proprietary chips either back then. Even without any service information, equipment was often simple enough to follow right through and figure out what it all does.

Not so these days.
With multilayer boards with internal hidden layers, surface mount components without identification, and no component designators on the board, its pretty much impossible to trace out a circuit. Then there are programmable chips that cannot be read or identified, and absolutely no way to get a replacement if the company is uncooperative or no longer in business.

Just about anything electronic these days is disposable, and just not repairable. And its made that way deliberately.
 
Its a bloody shame that component level repair has essentially been eliminated due to greed and 'planned obsolescence'.

Plus, as mentioned, current manufacturing methods make repair extremely difficult, even with provided info.

The only real solution to the problem is to DIY at the component level, using discrete parts, Arduino and PI to handle the digital logic elements. Some components on the Arduino and Pi boards (like USB controllers) are readily replaceable.

What is nice is that old TTL chips have holders, and that at the current amperage levels for solar and many other types, that some fairly ancient high current devices can work just fine.

In the old days a DAC was an expensive chip, whereas today a better DAC in a cheap NANO is a fraction of the price.

Combining old Analog with modern modular digital allows alot of room for design variation plus a reasonable repairability if something goes poof.
 
Its a bloody shame that component level repair has essentially been eliminated due to greed and 'planned obsolescence'.

Plus, as mentioned, current manufacturing methods make repair extremely difficult, even with provided into.

The only real solution to the problem is to DIY at the component level, using discrete parts, Arduino and PI to handle the digital logic elements. Some components on the Arduino and Pi boards (like USB controllers) are readily replaceable.

What is nice is that old TTL chips have holders, and that at the current amperage levels for solar and many other types, that some fairly ancient high current devices can work just fine.

In the old days a DAC was an expensive chip, whereas today a better DAC in a cheap NANO is a fraction of the price.

Combining old Analog with modern modular digital allows alot of room for design variation plus a reasonable repairability if something goes poof.
 
Thanks to ALL for the opinions.
I can repair anything electronics if I learn how it works. It has been my spoon 45 years. A manual teaches how it works, test procedures and diagnostics.
When parts are available, much easier. If parts are unobtanium, the resource is replacing modules/boards... As long as vision, steady hands, test equipment and functioning brain are there. :(
 
A few years ago when I finally decided to go off grid, the first thing I did was a complete energy audit of every electrical product in the house.
That led to tossing out a lot of my old kilowatt hour munching dinosaur appliances.

So I bought an almost new current model low energy refrigerator off e-bay for less than half the new sticker price.
I soon found out why it was so cheap.... It would intermittently stop working, destroying a lot of food.

After a bit of frustrating fault finding I determined all the sensors and switches were o/k and the problem was on the main microcontroller board.

No problem, buy a new circuit board, except I was told it would cost almost as much as a whole new refrigerator !
I spent hours looking at that board for cracks, dry joints and heat sensitive components, and eventually gave up on it.

Clearly the manufacturer would rather sell me a new refrigerator rather than help me to fix this one. BASTARDS !!

However, the user manual gave a detailed description of how it all worked, how the automatic defrost cycle works, and how that is modified by the number of door openings, and total accumulated motor run time and so on. So I thought I can do that with a very few digital counters, some logic gates and voltage comparators. No need for a microcontroller. So I built my own damned circuit board plus a spare. Plugged in the sensors and its still working perfectly today.

I am now in the happy situation of knowing exactly how it works, have a spare circuit board and can almost certainly fix anything likely to go wrong with it in the future.
This is my spare circuit board:
 

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I've long since given up trying to repair consumer level kit. I fell at the first hurdle looking at an LED TV that was emitting smoke whilst still actually functioning, I couldn't even get the back off. I bought a new one and gave the iffy one to my step-son who had it sorted by a local TV-chap for some nominal fee, it's in the grandkids bedroom now.

Meanwhile I'm not averse to looking inside faulty solar kit, the power devices are the usual failure point and they are still big enough for me to see. Many even have markings so replacements can be obtained.

I've also had luck talking to the technical support chaps of a couple of Chinese manufacturers. They won't give you diagrams or manuals for reasons discussed earlier, but they may well help out with defining the "stock faults" which happen commonly. "Replace Q10 and Q20, D1 is usually blown too" kind of thing, it really never hurts to ask.

Power electronics often suffers from "domino effect" where one device failing takes out several others, if you don't replace them all it all goes "pop" again. Long ago I used to buy "PSU repair kits" for satellite receivers (notably Pace 9000 series - it really was that long ago), replace all the bits in the bag and it would work again, no diagnostic skills needed.

I still do a bit of electronic design as a hobby and I'm not averse to throwing in an Arduino or ESP8266, but I'm not going to design an inverter or even an MPPT, too much risk of conflagration and they're not really that expensive to buy if you factor in your time.
 
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So I thought I can do that with a very few digital counters, some logic gates and voltage comparators. No need for a microcontroller. So I built my own damned circuit board plus a spare. Plugged in the sensors and its still working perfectly today.
?????

Yeah, I do not need a microcontrolled-triple-expensive clothes dryer to call me on the phone to tell me it is done drying.
 
A guy I found on YouTube once repaired relays on solar inverter, they were not clicking on for some reason so he opened the relays up and bent the connections until they came on easily. He then set it up with fake loads as if it was in a working solar array/system and he showed that they would now actually work, the reason I found the video was he was messing with the same make of inverter (zeversolar previously eversolar) that we had and our relays had just stopped working.

Fortunately, cos we knew the person who installed our system and it was within a 3 year warranty they just replaced it free of charge.
 
Sometimes you can be lucky...

But sadly, when an inverter fails, its often pretty violently, and all you are left with is smoke stained devastation to work with.
 
An apparent nearby lightning strike took out our 15 year old Outback 24V 3500W inverter. The fellow who put it in has been retired but was in our neck of the woods so came by and called Outback tech help. He had an old installer number with Outback and we talked. After trying several checks (there were absolutely no fault codes) that I had done numerous times Outback said to replace the control board first, then the FET board. Control board was less than $400 I think and FET board was seemingly out of stock but looked like it was maybe $800 when available? We chose to buy an updated model that dropped right on the Midnite Solar back panel. I disassembled that broken inverter and never saw a burnt part or anything untoward. Nor was I able to bypass the electronics to get basic function.
 
I have an Ampinvt 6000W split phase inverter.

For a few weeks of daily use it worked fine. Now, it works fine, but the DC amps are oscillating. If I have a load that should draw around 70A DC, the DC current is swinging from 0 to 150A. I put a digital ammeter shunt inline on the DC side and took 2000 samples at 4.678ms per sample and plopped that into a discrete Fourier thingy and have proven to myself that this thing is oscillating at 60hz.

I assume that there are a capacitor(s) (or maybe inductors) that are supposed to smooth this out, so that the battery does not have to deliver 2x current and deliver it at 60hz.

Am I right? Is my inverter broken? Ampinvt support is telling me this is normal, but I find this hard to believe.

I am now in the happy situation of knowing exactly how it works, have a spare circuit board and can almost certainly fix anything likely to go wrong with it in the future.
I would very much like to be in this situation. Can someone tell me what to look for and potentially fix?

I am reasonably handy with circuits having designed my own BMS (the cells send their volts and temps via bluetooth no less). However, for the most part that is all digital. I'm saying I can buy, remove, and solder in parts, if I knew what to look for.

Any advice is greatly appreciated.
 
I have an Ampinvt 6000W split phase inverter.

For a few weeks of daily use it worked fine. Now, it works fine, but the DC amps are oscillating. If I have a load that should draw around 70A DC, the DC current is swinging from 0 to 150A. I put a digital ammeter shunt inline on the DC side and took 2000 samples at 4.678ms per sample and plopped that into a discrete Fourier thingy and have proven to myself that this thing is oscillating at 60hz.

I assume that there are a capacitor(s) (or maybe inductors) that are supposed to smooth this out, so that the battery does not have to deliver 2x current and deliver it at 60hz.

Am I right? Is my inverter broken? Ampinvt support is telling me this is normal, but I find this hard to believe.


I would very much like to be in this situation. Can someone tell me what to look for and potentially fix?

I am reasonably handy with circuits having designed my own BMS (the cells send their volts and temps via bluetooth no less). However, for the most part that is all digital. I'm saying I can buy, remove, and solder in parts, if I knew what to look for.

Any advice is greatly appreciated.

I don't know your inverter, is it a low-frequency beast or a high-frequency "transformerless" design? Without knowing what the current was doing before you noticed the readings jumping around it's difficult to tell if it's normal.

I'd pop the lid off and look for any "burst" or bloated capacitors.
 
I don't know your inverter, is it a low-frequency beast or a high-frequency "transformerless" design? Without knowing what the current was doing before you noticed the readings jumping around it's difficult to tell if it's normal.
It is a low frequency beast. It has a nice big round transformer. It is a heavy unit.
I'd pop the lid off and look for any "burst" or bloated capacitors.
I am going to do that but am hoping to get some "architecture" description help. I mean something that describes what I'll find at the input side and output side and what, if any, these input capacitors will be like.
 
when one of my ebay grid tie inverters failed on first use i started the return process with photos of obvious faulty smd's and proof of voltages and polarity. The seller after talking with supplier offered me replacement SMD's to fix it. I could have replaced them but said i wasn't confident so they gave me a new one and didn't want old one back.
Now i'm here looking for info to repair hybrid inverter fault, I know its not the place here but my issue is. AC in and out work, PV in works. PV offsets grid use when no battery connected. PV powers up inverter when AC in is disconnected.
When connecting battery the bms detects short and trips. The inverter doesn't see any battery voltage and multimeter doesn't see short across battery terminals. I'm yet to investigate but i hope its something simple.
 
When connecting battery the bms detects short and trips. The inverter doesn't see any battery voltage and multimeter doesn't see short across battery terminals. I'm yet to investigate but i hope its something simple.
Have you tried pre charging the inverter capacitors? Otherwise, the inrush to fill those caps is huge and will often trip the BMS over current protection.
 
Currently I’m repairing a “broken” Huawei Sun 2000 3KTL L1 that our installer (I work in a company that install PV in Italy) broke due to a inverted polarity on the PV input. We tried to ask Huawei to repair it, they had denied it and told to ask a third part company to repair it.
We had sent it and they declared that it’s irreparable.
Now it’s half working, only one MPPT of two. Now it’s in my garage and I’m trying to repair it using my skills learned on the appliances PCB and school-academic electronic and electrotechnics.
I tried to find some schematics or indication, the only documentation aviable are on a sketchy webpage that asks a payment to read it, I had considered it a scam. Huawei (asking as installer) do not gave nothing more than the manual / datasheet, same as SMA, Fronius, PowerOne, etc..

I wanted to open a thread on it but I had a problem with my diy battery and wanted to tidy up it before.
I will post the repair and updates on the “hybrid - grid tied inverter” section.
 
I notice several of the contributors to this thread are new members. I agree with all the sentiment expressed but I have found a distinct lack of interest in electronics on this site.

I recently repaired a Fronius GTI but there was no reaction to the thread at all so I simply stopped posting.
 
I have repaired two inverters this year so far, the diagnosis and repair were in two places.

Aurora Power one was on YouTube, lots to choose from.

The SMA SB2500 was finally found on GitHub where the schematics had been posted.

Both repairs ended up being the same, remove and replace the DC relay's.
 
I notice several of the contributors to this thread are new members. I agree with all the sentiment expressed but I have found a distinct lack of interest in electronics on this site.

I recently repaired a Fronius GTI but there was no reaction to the thread at all so I simply stopped posting.
Please keep posting. There's often no rhyme or reason to why some posts get ignored.
 
I notice several of the contributors to this thread are new members. I agree with all the sentiment expressed but I have found a distinct lack of interest in electronics on this site.

I recently repaired a Fronius GTI but there was no reaction to the thread at all so I simply stopped posting.
Don't feel too bad. Our knowledge of electronics exceeds the capabilities of approximately 99% of the people that come here. Most visitors are just after information about solar and how to make it work. I also used to post technical information and came to the same conclusion as you. It's not worth the time since nobody really cares.
 
I notice several of the contributors to this thread are new members. I agree with all the sentiment expressed but I have found a distinct lack of interest in electronics on this site.

I recently repaired a Fronius GTI but there was no reaction to the thread at all so I simply stopped posting.
I must have missed your thread. I'm very interested in board level repair, but I'm also fairly new to the site.

I agree there is what could be called lack of interest. And on more repair focused forums like eevblog there is a lack of interest in solar stuff...

I find it strange, power electronics is one of the most satysfying things to repair and relatively simple compared with mobile phones etc. Also there is a lot less tools required. I consider a good desoldering station a must for desoldering mosfets etc. But it does contain lethal voltages and that is quite intimidating.

I do board level repair on surface mount (including BGA reflow) and through hole stuff. I'd love there to be more resources out there. Maybe even an open driver for some common inverter board.

The most difficult part of today's electronics is firmware and the sheer number of various MCUs. Between grinding off the markings and Knoxkoffs made in China... Unless there is a serial console header on board you can access easily it is a real pain.

Coming back to inverters. I recently saw very good YouTube video from the eevblog Dave. In there he had a drawing made by a forum member that showed a diagram of a deye hybrid inverter being dismantled. I think anyone repairing these things will find it useful. Screenshot_1718202296780.jpg
 
Sometimes I wonder if posting ideas here is really such a good idea.

There was an epic thread by @BiduleOhm, "DIY BMS design and reflection" it went for 36 pages and was excellent, and had a very strong following.

I have designed and built quite a few experimental BMS systems over the years myself, and now to my great regret posted some of the problems I encountered along the way, and how I overcame them.
I truly hoped others might profit from some of my own success in that direction.

That seems to have killed that thread stone dead.
Its now five months, and nobody has posted there since. Here is that last very lethal page.
https://diysolarforum.com/threads/diy-bms-design-and-reflection.4065/page-36

Another example, is that almost two years ago I came up with a way to build a really high power transformer cell balancer using a single large toroidal core with multiple low impedance windings.
For the technical, its a very low impedance forward converter, not flyback or using capacitors to transfer charge.

This produces extremely low impedance direct dc coupling cell to cell, and allows high balance current with very small millivolt cell to cell differences.
That was a quite unique approach at the time.

Going commercial with it would have been possible, but I knew if I did, the Chinese would copy the idea within a few months and sell them for less than the cost I can source components here in Australia to build them myself.
So for me, after a lot of work, there was more chance of losing money than making money.

I suggested this new approach over at the Back Shed Forum, and two people Mike, and Klaus built prototypes and obtained excellent results.
I knew it would be a total waste of time posting anything over here.

Anyhow, in recent times the Chinese are now making these and they are advertised on Ali Express, and the feedback from customers has been excellent.
Its so good, they even publish real genuine specifications I know are correct, which is unusual for the Chinese. Eight amps of balance current for a cell differential of 100mV, diminishing to zero current at 0mV differential.
That suggest a total cell to cell coupling impedance of about 12.5 milliohms which is quite realistic.

I was doing only slightly better than that myself two years ago, and it craps over any of the capacitor balancers everyone seems to be using.

So Great business for the Chinese, and great for us too as users. This is the new big thing in future commercial cell balancers I am sure.
If you do an internet search on transformer balancers, there is a fair bit of discussion, and all it quite recent.
But as far as I know, I was the first to come up with the idea.

But as a Forum DIY project it would be a complete total waste of my time to go to the trouble of explaining how it actually works, or show people how to put one together themselves.
The Chinese figured it all out very quickly.
They are smart, and work very hard, which is why we in the West are DOOMED.
https://www.aliexpress.com/item/100...nCirhZzm&utparam-url=scene:search|query_from:

Here are some now quite old pictures I took of my original first prototype.
 

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Sometimes I wonder if posting ideas here is really such a good idea.

There was an epic thread by @BiduleOhm, "DIY BMS design and reflection" it went for 36 pages and was excellent, and had a very strong following.

I have designed and built quite a few experimental BMS systems over the years myself, and now to my great regret posted some of the problems I encountered along the way, and how I overcame them.
I truly hoped others might profit from some of my own success in that direction.

That seems to have killed that thread stone dead.
Its now five months, and nobody has posted there since. Here is that last very lethal page.
https://diysolarforum.com/threads/diy-bms-design-and-reflection.4065/page-36
I have observed this "thread killing" by really valuable and technical posts on many forums including by myself. I'm not entirely sure why this happens, but I suspect it has something to do with the fact many people are interested in reading such threads (and they are an amazing resource if you find them years later by Google when they mention a solution to a problem you have), but I suspect many readers don't feel they can contribute at the same level so the thread dies. Especially on highly active forums most people consume through the "new posts".

Still I'd encourage you to post ideas and other technical stuff anyway as it is very valuable despite the lack of engagement.


Another example, is that almost two years ago I came up with a way to build a really high power transformer cell balancer using a single large toroidal core with multiple low impedance windings.
For the technical, its a very low impedance forward converter, not flyback or using capacitors to transfer charge.

This produces extremely low impedance direct dc coupling cell to cell, and allows high balance current with very small millivolt cell to cell differences.
That was a quite unique approach at the time.
I never heard of it and now I did. Thank you. It is a great idea I'd definitely buy, but I have to admit I do prefer the prices of Chinese knockoffs. I'd say from the point of view of sharing your idea with the world it has been very successful, but it feels bitter when others seem to be making money off your idea.

But as a Forum DIY project it would be a complete total waste of my time to go to the trouble of explaining how it actually works, or show people how to put one together themselves.
The Chinese figured it all out very quickly.
They are smart, and work very hard, which is why we in the West are DOOMED.
https://www.aliexpress.com/item/1005006073402783.html?spm=a2g0o.productlist.main.35.54a24b2dtyotda&algo_pvid=6b996848-c6a1-4d91-aee2-199c6659e504&algo_exp_id=6b996848-c6a1-4d91-aee2-199c6659e504-17&pdp_npi=4@dis!AUD!71.97!63.24!!!343.55!301.89!@2103241117188377948538471e492b!12000035607952743!sea!AU!0!AB&curPageLogUid=Wmo3nCirhZzm&utparam-url=scene:search|query_from:

Here are some now quite old pictures I took of my original first prototype.
You know if I had something like this I wanted to share I'd probably post it. I'd explain the tech stuff at a pretty high level. If people tried replicating it and had same problems I did I'd help them. But in such thread if I had posters asking for low level explanations of physical principles or with fundamental misunderstandings I'd probably just mention them and leave the task of clarifying to others.
 
Those transformer Chinese balancers don't work as well as the advertisers would have you believe, I have made my own balancer based on Warpspeeds original design, and they can work very well. I did purchase one off Aliexpress, an 8 series cell just to see what was in it. Seems they use a push pull inverter on each cell, all synchronized together, this differs from Warps forward converter on each cell.

When each cells inverter runs, by simple transformer action, any cell with a higher voltage will add extra charge current to a lesser voltage cell, this happens on each 1/2 switching cycle, so almost 100% of the time. However the huge currents they say you will get on these Chinese devices only occur if the cell voltages differ by almost 1 volt, not at 0.1v as advertised. Their transformer windings have pretty thin wire and the pcb tracks are not very large, so their impedance is higher than what can be achieved in a robust DIY design.

Cheers
Mike
 
Hi Mike.
Klaus was pretty happy with the version he built as well, he copied my design pretty much exactly.
The wire and tracks on those Chinese versions do look a bit thin, but I would have thought it should still work reasonably well.
But as we both know, the secret to success is keeping all the resistances of the cell wiring absolutely minimal.
I still think this concept still has rather a lot going for it.
 
I have repaired a few of those Chinese inverters, mainly its obvious what has blown up, causes seem primarily because of cheap under-spec components like capacitors, once these let go, then its cascade failure of any mosfets etc being powered by them. Its really guess work if you can fix them as schematic's etc are not to be found.
As the eeblog says, they will say they have named brand components, but quite often not.

Cheers
Mike
 
You can be lucky sometimes.....

I was once asked to fix a Make Sky Blue solar controller by a Forum member. I discovered that the problem was a really small transformer that supplied some isolated dc power to the isolated input section of the controller.
As I remember, it had an open circuit winding, the whole transformer was about a 10mm cube in size, using hair fine wire, and all epoxied together into a solid lump.
Impossible to dissect and reverse engineer as is often possible with larger transformers.
So not really fixable, at least not realistically with all the time and effort that would be involved in designing a replacement from scratch.

As a replacement solar controller would not be all that expensive, that was the final outcome.

Its interesting though. Many non technical people seem to think that because something only cost a couple of hundred dollars to buy new, it should also be fixable very cheaply. It difficult to explain to them that it might take at least a full days work plus the cost of the parts.
Also, if you do fix it, and it blows up again in a years time, the second blow up is all your fault.
 
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Many non technical people seem to think that because something only cost a couple of hundred dollars to buy new, it should also be fixable very cheaply. It difficult to explain to them that it might take at least a full days work plus the cost of the parts.
You should try explaining to the 3rd owner of a $100k BMW or Benz why their repair estimate costs more than they purchased the 12 year old 200,000 mile car for...
"What do you mean it's $8,000 to fix this one problem and $12,000 to fix most of the worst stuff wrong with it?"
Also, if you do fix it, and it blows up again in a years time, the second blow up is all your fault.
I feel that pain.

I've got a question for you guys that do PCB level repair. How do you get started? I can typically find a cold/cracked solder or bulged capacitor, but past that I've never had luck. I can start probing voltages and following the inputs or measuring for shorts (whichever is applicable) but I've never had much luck making heads or tails of a PCB. My brain just needs a wiring diagram.
 
I've got a question for you guys that do PCB level repair. How do you get started? I can typically find a cold/cracked solder or bulged capacitor, but past that I've never had luck. I can start probing voltages and following the inputs or measuring for shorts (whichever is applicable) but I've never had much luck making heads or tails of a PCB. My brain just needs a wiring diagram.
In my case reverse engineering mixed with a heavy dose of intuition. Having spent a lifetime designing circuits there are only so many way's something can be arranged so the schematic forms itself in my head lols Most of all collecting clues and a process of elimination, especially useful are error codes and interpreting chinglish writings!
 
I notice several of the contributors to this thread are new members. I agree with all the sentiment expressed but I have found a distinct lack of interest in electronics on this site.

I recently repaired a Fronius GTI but there was no reaction to the thread at all so I simply stopped posting.

It is a normal reaction, most of guys are very good in knowing the business very well, but that not means that they are experts in electronics. Those post will become handy on a day when one of us will encounter a failure, so then you will get your reward. In my case I posted a thread with modification of easun 6048 charging controller, and it took several weeks before someone get interested and followed my project.

So posting our "advanced" stuff is mostly for guys with "this thing" that allows them to overcome the "magic smoke" work, especially when it is needed.
In fact we need to admit that working on inverter is a dangerous work, as one could get electrocuted or melt all home appliances in no time...
 
I experienced the golden age of electronics where a circuit was almost visual in the way it laid out. Now packaging makes it almost impossible to repair anything. At least I lose interest before I even start. A while back on another forum fourtytwo did a PV boost water heater build. He has never posted it here. This is a very non technical forum and the majority do not understand the fundamentals of solar panels, ohms law or basic math (like the power of squares). There is nothing that teaches you more about principals of solar than heating water. And almost nobody here can heat water effectively. At first I thought it was amazing that a whole industry was built upon a community that had no understanding of what they were doing. But then that is the automotive industry. If you can open the door and find the key, you are good to go. Hook four wires up to a charge controller and your mother can tell anybody who will listen that their child is an electrical genius. And most people just want to accomplish a task, not know why it works. Electronics takes some investment of time and money.
 
You can be lucky sometimes.....

I was once asked to fix a Make Sky Blue solar controller by a Forum member. I discovered that the problem was a really small transformer that supplied some isolated dc power to the isolated input section of the controller.
As I remember, it had an open circuit winding, the whole transformer was about a 10mm cube in size, using hair fine wire, and all epoxied together into a solid lump.
Impossible to dissect and reverse engineer as is often possible with larger transformers.
So not really fixable, at least not realistically with all the time and effort that would be involved in designing a replacement from scratch.
That is really a bummer when it happens. You know what's broken, but you can't find a replacement part.

I've recently found a good cache of Voltronic service manuals.(if there is interest I'll post) Although they are written for other devices than what I have I can see the same functional blocks being reused. This will ve immensely helpful when they break.
I've got a question for you guys that do PCB level repair. How do you get started? I can typically find a cold/cracked solder or bulged capacitor, but past that I've never had luck. I can start probing voltages and following the inputs or measuring for shorts (whichever is applicable) but I've never had much luck making heads or tails of a PCB. My brain just needs a wiring diagram.
For me it is often one or the other:
- if I have a service manual, the markings have not been ground off chips, I have schematics or the circuit is laid out easily and I know how it works it is pretty straightforward.
- option two, far more common, I have no clue whatsoever, it uses a 6 layer board and marking off chips have been ground off, are

In such case I just do the basics, is anything burned? If there are mosfets/diodes are they busted? If I can power the circuit does any part get hot? (a thermal camera is an amazing tool). If all fails and I can't power it up it goes into a junk drawer 😕 If I can power it up I'll probe it with an oscilloscope /logic analyser until I find some clue what's wrong or I get tired and it lands in "things to fix in future" box.

Also If it has markings on chips I find what they are(this becomes increasingly difficult with some companies putting 1-3 letters on tiny smd chips - good luck researching it), their datasheets and application circuits.

Also I have a soldering microscope for smd and tiny "mobile phone pcb repair" insulated wire with solder through insulation. It makes it possible to hook up to the tiniest of chips.
Also, if you do fix it, and it blows up again in a years time, the second blow up is all your fault.
This is why I don't fix stuff for others (except close family). For myself when a thing breaks it almost always happens on a Friday afternoon (Murphy's law etc) so fixing it is the only way to have the device not be off till mid next week. I tend to buy replacements then anyway to have as a spare. Then of course the original never breaks again 😁
So posting our "advanced" stuff is mostly for guys with "this thing" that allows them to overcome the "magic smoke" work, especially when it is needed.
In fact we need to admit that working on inverter is a dangerous work, as one could get electrocuted or melt all home appliances in no time...
I'm not even bitter there is not that much interest here, but I am that on electronics focused forum there is also. Post some high power high voltage related stuff and people assume you're a beginner and there are 3 pages of how you're going to electrocute yourself, how shit Chinese electronics is and this design in particular, how you're a fool for not mortgaging your house and buying western made stuff and so on... Everything, but the answers to actual questions you ask when troubleshooting... This is pretty disappointing.

I experienced the golden age of electronics where a circuit was almost visual in the way it laid out.
I collect lots of vintage electronics and I have quite a few vacuum tube devices including this HP a voltmeter made in 1960s:
Compress_20240622_130634_4547.jpg
It is extremely sensitive and the problem is it starts self resonating few minutes after it's powered on.

I have the service manual and a schematic(of a very similar model). I've been at it twice and I still haven't fixed it.

Give me any modern device I have so much info on and I've probably fixed it long ago. So let's not overestimate the good old days :)

Unless you mean a specific time for example 1970s. Yes I love high end (usually ham radio and test) equipment made in 1970s. It is all semiconductor based except high power and RF amplifiers so it is fairly easy for me. Often service manuals co tain not just schematics, but a good discussion how the circuit works and troubleshooting steps as well as images of both sides of the PCBs and the soldermask so you can remake a pcb if required... That was absolutely amazing and we should go back to documentation like this.
Now packaging makes it almost impossible to repair anything.
I do enjoy working with tiny tweezers under a microscope :) I actually like SMD stuff since I bought the microscope.

Hook four wires up to a charge controller and your mother can tell anybody who will listen that their child is an electrical genius. And most people just want to accomplish a task, not know why it works. Electronics takes some investment of time and money.
This👍
 
I've got a question for you guys that do PCB level repair. How do you get started?
I start with the error messages and then google it for previous repairs, other than using a multi-meter that also measures capacitance the other tool I use is a microscope for viewing the board tracks, soldering and the writing on the smd component's. I am more used to rebuilding engines so not a natural environment for me but the money saving is good.
 
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