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Pin 1 of L7210 says 0.544v. That’s all I should have written about that. Sorry!

Sorry, back where you asked me to post L7210 voltage after 15s. I had done that before reflashing the EFI BIOS and the readings were 1.078 on pin 2 and 1.08.2 on pin 1. Now that reading is 0.544v. PPVCC_S0_CPU is 1.074v

5.1v at L3500 and 36.3mv at LB700. I've done PRAM and SMC reset a few times, but no luck. After disconnecting J800 and having the external display connected on the usb-c port, still no display. Two things that might also be worth mentioning. 1. I only have 3 of the 4 USB post working, as one...

It does not appear to have any activity on a USB thumb drive with a light on it, nor does it show video on an external display.

I picked up a CH341A programer and was able to get a clean EFI BIOS written with my own serial numbers. It's back on the board and the voltage IS now going down after 10 -15 seconds, but it's going down to 0.544 volts and still no image. still 19.8v and 2.50a (after half hour or so it goes to...

Oops! Yes, you're correct. Injecting 1v through that pad shows nothing individually getting hot, but the entire area at 10.48a and when touching the power probe it's hot at the tip with a little spark. I guess CPU is done.

After injecting 1v into that pad the PSU goes up to 0.20a. I've have looked carefully under thermal camera on both sides of the board and I don't see anything. Nothing seem even warm.

Thanks, I will give that a try. I have the lab PSU. Will any of the caps on that line be fine as the injection point?

For sure it's zeros anywhere on those lines, so I guess the CPU is done. Thanks for the info!

So I guess the CPU is dead then? The readings are not the same with a working board. On the working board the same lines all read 1 ohm and in continuity mode they will give a quick beep then stop on the multimeter, but on the broken board they go straight to zero, and a solid beep on the...

On a known working board I see the none of the same lines appear to be shorted to ground, although they do have a very low resistance to ground. How in the world would I be able to isolate if there is one bad cap on these lines or does it indicate an internal short on the CPU? None of the caps...

Everything on that line reads 0 resistance to ground. With the board out of the case and not plugged into anything else, the voltage is 20v and it goes from 0.07a then to zero every few seconds. the only two chips that even get warm are the T2 and U7650 and they just pulse on and off along with...

I have a A2179 with a 820-01958-A board that seems like it's bad. Here is a photo of the shorted area. Everything on these lines are shorted...

Ok, thanks for the info. I understand what you mean now. I had checked the diode mode to ground on all big coils, including the small ones corresponding to SDD, but wasn't sure exactly what the readings should be. I get some of the small ones that are 4.11 and some that are 0.11. The big ones...

PPBUS_G3H is at 12.64v then drops to 12.33v when the amps drop to 0.00a from 0.05 now that it's just the board. When i first plug the board in it starts at 5.17v and 0.25a then goes to 20.2v and 0.05a. Coils look ok around U7800.

AWAKE voltage is 1.206 at pin 1 of C7914 and SLPS2R voltage is 0.799 at pin 1 of C7905 ... and both go to zero and back to those voltages after around 20 seconds. i do not see any knocked off components, but the MacBook died while it was being used and that's why he replaced the battery in the...

I just checked and it is 87w charger. No power to CPU rail with or without board connected. With everything connected in the housing it goes to 20v then ramps up to around 0.77a then goes back to zero and starts again. Board alone goes to 20v and goes up to around 0.05a and bounces around from...

I have changed the mux twice with a brand new one, but it did not change the result. :(

I’m working on a 820-01700 that was liquid damaged. The LCD assembly was fine looking, but the connectors were completely corroded and burnt away. The connector on the logic board looks perfect. I installed a new flex cable between the new display assembly (tested and working by the way) and...

The MacBook was working fine, but then it seemed like the battery was dying fast, almost suddenly, then it just stopped turning on. The guy that owns it did a battery replacementI, but had no luck getting it running. After opening it up I noticed the lock clip missing from the battery connector...