Slow charging but no screen

I purchased a broken switch in hopes to repair it to use as a docked device. Complaints were that it would not charge and that there was no screen. Watching Steve’s videos, I opened the switch up and determined that the USB port and video chip were bad. I have replaced both and tested the switch again. I get .40-.41a charging. It does not drop to zero and start fast charging. Knowing that this would be a docked switch, I put it back together enough to test the screen, and I get nothing on the screen but still get .40-.41a charging.

I have tested a lot of the big capacitors around the board and none of them are shorted to ground. I have replaced the M92T36 chip because I ordered a new one and the same thing.

So the P13USB, M92T36, and usb port have all been replaced. I do not think I have a bad battery because it is doing the exact same thing to the other battery I have from another broken switch that was used for parts before I bought it on ebay (crappy of that seller).

Anyone have any ideas?

Unfortunately, this is not a problem that I’ve been able to fix. I’ve had quite a few of these come through my shop but just haven’t ever been able to find a fix for it. I think it’s probably a faulty CPU but no way for me to know for sure.

If your donor board has a good cpu try replacing it with that

Well that is unfortunate. I believe the other one is a faulty CPU as well because there are shorts ALL OVER even with most of the major chips missing.

Since I seem to be having really bad luck trying to fix these, I am not gonna throw any more money at them. Would you like them to use as parts? The screen/cases are probably B-C on your standards.

Honestly, I actually have quite a few parts boards. It might be a good idea for you to keep them in case you need them in the future. Thanks for the offer though.

Hey there,
just out of curiosity: does your charger really support high speed charging with 20V? Not all do… But still, you should get the charging icon on the screen…

Really high, no. I usually either use the dock charger or a Tronsmart that will charge my normal switch just fine so I know it is beefy enough. But there is a new thread posted today that may have a possible fix for this situation so I might be trying that tomorrow.