I have a faulty switch which I try to repair. Once I removed the USB port I have seen that one trace is missing. I put in a new port and also changed the MT92 due to a short.
Switch still not charging and it ends with 0.7A.
I suppose that maybe the missing PIN / trace causes such a defect but do not know if this pin I needed and if where I can use a jumper wire to test if this works.
Any information where this marked PIN belongs to or any other advice would be appreciated.
The marked pin is a data pin and it goes to the pi3usb ic on the backside. (Should be the TX1+ pin)
Hi @Calvin - thanks for that information.
Have wired the connection to the PI3USB - but seems not to be the (only) problem as switch still is not booting and end switch 0.7A - have not seen any obvious problems yet, but also does not know the history of that switch.
Oops I did it again…
Wrong picture. The names on the lines to the pi3usb ic are not correct.
Here is the correct one:
Thanks for the update - just seen that I wired it wrong on the first try - after further diagnostics I have seen that I have a short on the M92 - not sure if the chip is not placed correct or it might be another problem.
Any ideas what could cause that short here ?
This cap goes to the CPU!
I am afraid that there is nothing more to do on this board.
Well, thanks for that info - even after pulling off the cap there is still a short. Knowing that this is probably not fixable helps me at least not wasting more time into that Switch - so thanks for clarification
While that line does indeed connect to the CPU, it doesn’t only connect to the CPU, I believe it also connects to one of the rails coming from the PMIC, and so could be pulled down by anything else connected to that rail.