The romlog is a canon firmware feature, so it means the canon firmware did not generate a romlog for whatever error caused the shutdown.
Hm. Guess I will try going the UART route. Maybe there will be some hints there. I believe I have identified the UART pins.
I wouldn't expect a dedicated "detect" pin, more likely some specific conditions are expected. Presumably, it can be spoofed with enough effort.
Unfortunately I have not found much detailed tech info for the A4000. Does not appear to be a service manual online. The only chip on the device that I cannot identify is the AA1900, which is listed as a "video processor" on that russian site, but I don't think it has enough pins to be the LCD driver anyways and there is no datasheet I can find. Can't locate a datasheet for the LCD either, although it does have 40 or 41pins which is a typical number for a TFT LCD (accounting for 24x color signals, h/vsync, clock, power/gnd, backlight power). AFAIK these LCDs don't typically have any "read" interface capability, but it does have logic onboard so it is possible. I assume there is a backlight drive circuit on here which is driving a constant current, it may be an error related to the current level which would not be hard to spoof (if I can figure out the correct pins). As is typical though... everything is incredibly tiny and impossible to probe on this board! There are some LCD breakout boards available on the net, possible I could find one that matches.
I am willing to take this a little deeper on the science fair level, but at some point it will become not worth it! Appreciate all the tips on here!
