820-3787 No display when battery connected

dr. moast

New member

I have a 820-3787 on my bench that came in with no image. Found L8300 was burned and replaced it, now image is fine and the device works without issues on magsafe only. However, as soon as the battery is connected, the device refuses to start (chimes but no image) or if battery is connected while the device is running, it will immediately freeze.

Replaced the battery and was able to start it a few times, but every 5th or 6th start it will freeze. As long as it is on magsafe only I can restart a hundred times without a problem.

ASD shows no error (except battery temp sensor, as battery must be disconnected to start ASD).

Any hint anybody?