No Voltage on Pin 29 of TPS51980A - Mid 2015 MacBook Pro 15 Inch
I was using my MacBook charging at around 70% capacity when, suddenly, it powered off and wouldn't turn back on. The charger showed an orange light still. Trying SMC reset turned the light green, and pressing the power button it goes back to orange. I tried the key combination to force a boot on AC only, but nothing happened
I pulled the board and followed Louis Rossmann's diagnostic video for an A1398 with no power: here
I get 12.7V on PPBus_G3H, 3.6V on PPVRTC_G3H, 0.1V on PP5V_S5 (pin 29). SMC_PM_G2_EN (pin 12 enable) reads 3.4V as expected, and pin 23 getting VIN 12.7V as expected.
In the case of the video, there was some signs of damage around the chip and it was outputting 1.1V. Mine appears to be clean and it outputting no voltage.
Are these chips a common fail item, or should I be digging deeper for a possible other cause? I don't have a schematic or board view currently, just relying on images in videos. The only thing I've done to the machine recently is put in an aftermarket battery, but it's been fine for multiple weeks.
Thanks!
UPDATE: Checked again, and PP5V_S5 is shorted to ground... measured about an Ohm
Is dit een goede vraag?
@x58guy what is your actual logic board. Is it a 820-3662 board or is it a 820-00138, 820-00163, 820-00426? Post some well focused, large images of your board (Top and Bottom) with your Question Voeg afbeeldingen toe aan een bestaande vraag
door oldturkey03
@oldturkey03 it's an 820-00138. New pictures attached.
door X58Guy
@x58guy oldturkey3@gmail.com send me an email. I can share something with you which I can't on here. Thank you for the images but they are not clear or large enough to zoom into :-)
What voltages do you get on pin 22 and 13? Did you check pin 4 and 21? Remove C7505 and see what you get regarding your short to ground
door oldturkey03