Attempting to service this same iMAC pro with a 'no power' case. A few corrections. Apple (Foxconn) DOES have a bank of DEBUG LEDs onboard. By default, they will not light up unless you press the tiny pushbutton that is just below the same row of LEDs. If the first left LED enables with the pushbutton, then the power supply which is feeding the 12v rail is ON. Be very cautious of the high voltage near the exposed power supply. This unit is a shock hazard. After some probing, we are facing that PP1V8_S5 is @ 0 volts. All rails from this and lower are at 0 volts. On a macbook, usually a DFU corrects the PP1V8_S5 rail. For us, even with numerous attempts using Configurator 2 and different USB cable, facing Error Code 9 on the DFU revive process. Currently stuck on this repair. From our understanding, PP1V8_S5 is created by a leg on the PMIC @ U7800. Do not feel like replacing this complex PMIC nor know of reliable of sources for this part. The higher current BUCK3_LX0 leg IS WORKING. No short on the missing...

29 ohms to ground is not considered a short on the Vcore (CPU) rail. Test with a known good magsafe (original is preferred) power adapter. It is ok to remove the battery and test with the external power adapter only. Does the logic board power up and remain to be powered with the external adapter ?

Not to necropost but some of us techs are reviewing this case on the badcaps forum. The error code appears to be common but most of the threads on this topic are now locked. This is a deja-vu of the iMAC days where the GPU / video card had to be reflowed due to solder joints underneath the BGA (ball grid array) devices becoming undone. This is a process but with care it can be done by DIY. Google for the GPU reflowing fix or take it to a shop that understands this lingo. We run an electronics design firm so have $100k USD invested into our SMT oven which has worked very well to fix the 'dead' imacs. Don't give up even if the vendor who sold you the laptop does. There is still some hope and many are reporting success after reflowing of the GPU on the logic board. Hope this helps.

I know that this is an old thread but the video card can be reflowed again. We have done this with our 9 zone SMT oven with success on 10+ iMACs. The fix does indeed work. Reballing the GPU is not required. Been working for weeks to date. The bars are gone and the machine is once again stable. Some claim that this is a temp fix but keep in mind that it likely took years after the initial purchase for this failure to surface. Also strongly blaming the caking up of the heatsink compound on the video card and CPU for these issues. We are removing the old heatsink paste / pads and replacing with the latest and high grade pads from T-Global (Taiwan) - digikey carries these in varying grades. The thermal properties is much higher than other off brands. After the process, notice how cool the back on the iMAC enclosure is as compared to before this exercise.

Please also review this great compatibility chart: http://wiki.level3.repair/index.php?titl...

http://wiki.level3.repair/index.php?titl...

Hi. Found this thread through Google to understand what is Error 35. Apparently a new tool is being released by JC (Shenzhen, CN) to fix this error code. However, the fix requires the removal of the NAND flash device and their tool (BGA110 P11F) to be released in January.