Customer came in for data recovery, came to find out data is soldered on to this iMac (learn something new everyday) this is a 2020 T2 iMac so I was surprised because the iMac Pro has a T2 chip and it isn’t soldered on. Anyways, the iMac boots to Apple logo and then restarts, before it turns off you hear a quarter fan spin then it repeats itself. I decided to do a DFU revive to restore any hardware firmware issues and it was successful in reviving the device however the issue persists in boot looping. It shows the Apple logo for like 40 seconds then turns off and fan spin rinse repeat. I...

Hello,

I am currently trying to help a ONG by volunteering to help repair laptops, it's something that i have been into since 2017, always watching videos, on discords, forums etc...

I have an HP ProBook 4510s laptop that does not power on and has no indicator lights, which suggests an issue with the power supply or the motherboard.

I started by verifying that there is voltage at the input of the motherboard, confirming that the power adapter is working correctly. However, when I checked the voltage at the output of the first MOSFET (Q1032), I found 19V at...

iMac turns on no drops no cracks, tried to DFU Restore the iMac, logo turns on great! however iMac turns itself off and then restarts to the (!) icon and won't post the restore. Tried thunderbolt 3 cable, tried regular USB C cable and nothing.

this is the message it gives me with the error

Unexpected device state 'DFU' expected 'RestoreOS' (Probably forced into DFU mode externally) [com.apple.MobileDevice.MobileRestore – 0xFAE (4014)].


Any thoughts what this could be? I will open it up and repair it but I am not 100% sure since this iMac doesn't...

Good day everyone.

I have been scratching my head with a Lenovo laptop I got in today.

The laptop had no power and taking no amps from the power supply. Checking voltage showed 20v only on one side of the first mosfet. Took it off and replaced it and then same story. Took off second mosfet and then the first mosfet had the right voltages as well as 25v on gate is it should. Replacing the second mosfet the problem started again.

Even using a wire to bypass the second mosfet does the same interference with the first mosfet.

Would anyone...

I am trying to fix an iMac 2017 PSU, initially came with a blown fuse and shorted PFC MOSFET (6R199P). After visual inspection and some measurements I replaced the FET with a P20NM60 and tested with 100w series lamp, and it lasted 1 second before going into dead short. The PFC controller chip (NCP1605BG) and its passives appear fine (passives measure OK), but I do not know if there is a simple way of testing the NCP1605 as I wouldn't like to blind-replace it.
There was some slight blackening of the solder on the PFC controller passives so I reflowed them all with some flux. I am waiting...