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Started with 1V, nothing was heating, bumped to 2V, SMC got a little bit warm and DCPS showed around 250mA draw. Tried again 3V, draw was 150mA. SMC was again little bit warm. PP3V42 is now present, PPBUS_G3H is 12.54V. Green light present. No fan spin. When I connect the charger, SMC is warm...

PP3V42 has 0 Ohms on System side. Inject 3.42V and see what gets hot?

Doesn't work. I'm holding Alt key, no image on screen, just backlight works. It's stuck with bad SSD. I plugged OSX pendrive in case it boots directly from it, but nothing. The pendrive doesn't flash.

Currently, I have not way of testing it. I see that the computer doesn't want to display anything when bad SSD is connected. As said, it chimes and gives backlight, but that is. With good SSD, it works. When measuring pins on SSD itself, they show 0.018V instead of 0.335V. Is there a way to...

I'll try that. I took measures from both drives when connected, bad drive pulls 2 signals short (pins 30 and 31) Good SSD: Pin 30 - 0.337 Pin 31 - 0.342 Bad SSD: Pin 30 - 0.018 Pin 31 - 0.019

Well, tried OSX pendrive, it boots. Tried another SSD, it shows a question mark (it's empty), so that's good. Bad news I guess - bad SSD. Repairable?

Alright, I’ll first replace a couple of bad looking components, mentioned above, and report back. If SSD power is not good, should I get to Question Mark screen eventually after a minute from starting laptop?

Orange light, chimes, backlight on, no picture. The battery had no juice, I plugged the charger for few seconds then unplugged it. The screen showed "battery charging symbol" which concludes pictures is there after all, the screen is good. Inspected motherboard for visual signs, found water...

Thank you very much. Please mark as solved.

I'm back to this post after a while. Does someone mind correcting this BIOS file after all? (delete ME Region and Fsys area) Here is the link: https://www.dropbox.com/s/05anvm78xurgbai/C02G4B7FDRJ7.BIN?dl=0 Thanks

I have replaced the cap and laptop works fine. Mark as solved, please. Onto the next one...

There's still so much to learn. Okay. So none of the big coils had odd values. I took a look at C7333 from the side and to my surprise, it did have a slight crack. I removed it, PPBUS_G3H measures 0.8MOhms. Is it safe to attach the charger to see if the fans spin or shall I first replace...

So it is safe to put 5A (which is what DCPS can be set at) with, for example, 3V and let it flow through PPBUS_G3H without damaging CPU? I'm going through coils with multimeter and resistance mode now, didn't inject any power yet. Note: when the adapter is connected (only once I did it)...

Excuse me, my bad. I didn't express myself right. 1V with 500mA is 1V set with 500mA as a limit for current on my power supply. It depends on the device itself, resistance on that rail, how much it will draw. The exact value of the short is 0 Ohms. On to the hunt for big coils with the same...

I have removed F7140 and F7141 and the short is on the TO SYSTEM line. What would be the next step? To inject 1V and 500mA to PPBUS_G3H?

Okay. Mark as solved then please.

No short between pads. Simply PCH failed for some unknown reason. Can it be replaced?

I’ve removed the caps too. Still 0 Ohms. Prior to reflow, PPVRTC_G3H measured around 36kOhms. I didn’t connect any power after. Could PCH reflow help?

So I have reflowed U1900 nice and easy since I thought it was not making a good contact. U1100 looked clean. After reflow, I get 0 Ohms on PPVRTC_G3H... I've removed then U1900, still 0 Ohms...

I went through the list of rails and noticed PPVRTC_G3H is 2.7V instead of 3.42V. Resistance to ground on PPVRTC_G3H is 36.5kOhms or 0.391V diode mode. So to inspect that rail first?