Drinking game: For each wrong guess, we have to drink a shot. It won't actually help
@Supervstech, but it'll make it more fun. No guessing while driving!
Photographic quality is outstanding! Perpendicular to the board so we can see the writing on the PCB is great, angle shots we can look for discoloration/bulging.
Some of the photos are a bit of a puzzle ... what would help me is a wide-angle "reference shot" of everything with "markers" on stickies. Every other photo could then be referenced back to that marker. Ideally, that photo keeps getting updated as you test through the circuit with voltages/test-results. For example, color over traces with green for 12V, blue for 5V, Green dots on things you've tested (I typically use the windows built-in "snipping tool" as it's fast/easy at that sort of stuff).
It would also help if the photos had shorter more meaningful names, otherwise when I ask if the white connector in photo 20210424_205533 is of the balance leads most people
won't bother to look as too time-consuming to correlate. (update: also helps me from making mistakes, just had to update one of the photo names in this post).
What's the battery's cell configuration (e.g., xSyP)?
Is CH2 FAN in 20210424_205547 a photo blemish, or is the connector actually partially melted? If so, that might be a trouble area.
At the top of 20210424_205547, water damage or did a protective layer on the PCB melt off? What component is on the other side?
Might be worthwhile to test it.
To me, the board looks like it's in pretty good shape. So my money is on a blown capacitor or FET.
Nice list! Using the mosfet testing instructions in the
video from post
#17 those should be easy to test.
As it makes sense for the display to be DC powered and it doesn't light up, I suspect a mosfet in the BMS keeping DC power from flowing to the rest.
Put alcohol on the board (wet it), then try to power it up. (work fast)
So that's how they tested that before IR Imagers!