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We can mark this one as solved… for some reason. Left the board overnight on the desk and when I went back this morning, short was gone. Replaced UC810 and now Mac turns on and everything seems to be functioning properly! Didn’t realise UC810 is actually responsible for that power rail but no...

Ok, so got 2 donor boards in today that were iCloud locked boards. Both boosted to 20V so I took U5700, U7000 & U5340. Now I get all voltages but the Mac still won't boost as PP3V3_S2SW_SNS is shorted and causing UC810 to pulse. Removed UC810 and injected voltage but nothing is getting hot...

Removed U5700 and short is gone. Will dig through my donor pile tomorrow to see if i have one. If not then will need to order it in. Could a bad u5700 be the reason i’m missing voltages on the other pins and on both sides of R5710?

Yes R5710 seems to be 0v on both sides. Strange thing, I left it plugged in for a while while I done other repairs and now PPBUS_AON is hard short to ground, definitely wasn't before and U5700 heats up like crazy when I inject 2v to PPBUS_AON. Could a bad u5700 be why I'm getting no voltages?

Thanks for the quick reply. U5700: Pin 8 - 12.28v Pin 6 - 0v Pin 7 - 0v Pin 5 - 0v Pin 12 - 0v Pin 8 is getting power but everything else is reading in low mv (60-100mv) but it's the same even when I'm not measuring so I'm assuming its just my multimeter. EDIT: No shorts on any of those pins...

Hi, We have an M1 MacBook Pro in right now that is stuck on 5V. Customer states it ran out of battery then wouldn't charge. The board is clean with no signs of liquid anywhere. I have tested all LDOs and none have shorts, I am getting 12.28V on PPBUS_AON but 0v on PP3V8_AON. No shorts that I...

OK DEFINITELY solved this time around. one of the lines from L500 was pulled to ground. Replaced CD3217 again and all is working as it should. Thanks for the help 2informaticos!

SCRATCH THAT: USB ports function fine for USB DRIVES only. Will not see a mouse, keyboard or customers MIDI devices but will see and boot my MacOS installer drives no problem.... This is in OS and also on Boot menu. strange

SOLVED - Replaced both CD3217 chips and all functionality came back. Bit of a strange one as no liquid anywhere on the board.

Hi, got an M1 MacBook Air on the bench. Unit is extremely clean with no signs of a drop or liquid. Unit will power on as normal but will only charge NORMALLY from the USB C port closest to the user. the other port stays at 5V 0.3-0.4A and no cycling (CORRECTION - unit CHARGES at 5V3A when...

SOLVED! (I think). RB090 which connects PP3V3_UPC_TA_LDO and TBT_ T_ROM_HOLD_L was hanging on by a thread. No corrosion near it but I must've been putting just enough flex on the board for it to start up. Replaced and now I'm getting 20v correctly and consistently. Wish I noticed that before...

ok, reballed UB300 and UB400. Still the same issue. I've found I don't need a lot of pressure at all to make it get 20V but I have also noticed that while all 4 ports charge when the Mac is on, only the left side gets USB activity. Could this still be CD3215 issues?

I have already tried external USB. It gets loaded to a point then just reboots. J9600 looks very clean and I would remove it entirely if I thought that was the only way. Kinda nice having the lifeboat connector there JUST incase there is no other option. Not too sure if it would work due to the...

Ok, I reflowed U2800, UB000, U3100 and U3200. the CD3215 IC's are normally underfilled but when I got this board it was removed badly from U3100 and U3200. UB300 and UB400 have still got underfill but what I noticed is that if the board is out of the housing, it's stuck at 5V and restarting...

The Mac went to sleep and kernel panicked again. Full report below: panic(cpu 0 caller 0xffffff802141705a): "DSB0(MacBookPro14,2): thunderbolt power on failed 0x15788086\n"@/AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/IOPCIFamily/IOPCIFamily-428.40.7/IOPCIBridge.cpp:1428...

Another 820-00923 that had severe liquid damage. I had to replace the thunderbolt controller chips, the U7000 charging IC and remove a short circuit on PPBUS_G3H to get it working. It works great when it isn't in sleep mode or trying to update. I am actually typing this message from this board...

I have got an 820-00923 with some heavy liquid damage around one of the thunderbolt sockets. It has been cleaned and components replaced to the point where it will turn on and pass AHT with no issues. but as soon as I type the customers password to login, the loading bar starts and then the...

Yes the programming is different for each board but the SMC chip is the same. Also you cannot buy brand new SMC’s, they have to come from donor boards as they cannot be programmed once out of the factory. On the 4924 boards the fan doesn’t spin until it gets past a certain temperature. Did you...

Thanks @2informaticos, it worked great! this can be marked as fixed.

Thanks very much! is it possible the new EFI just wasn't programmed at all or the FSYS could've been corrupted after updating the new EFI for Catalina etc.?