2015 13" Macbook Pro 820-4924-A green and orange light no fan spin

Mac-N-Sauce

New member
Have a 2015 13" retina. Do not have schematic so using and earlier model, but appear the same. Gets green and orang light, no fan spin. Some minor water damage.
Hit the U1950 area. Someone before me tried to replace U1950(Failed). I replaced it, Plugged it in and got fan spin. YEA!
Then I reinstalled board and connected everything. Would not turn on. Took it back out, checked it all again. I am missing PM S0 PGOOD, have ALL_SYS_PWRGD and CPUVR_PGOOD
Any, thoughts? Lost on this one.

Could the chip be bad?
 
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Mac-N-Sauce

New member
No, I didn't before , but I have and its blown. So I tried to run a wire from the capacitor to the pin and replaced the U1950. Fans spun, then shut off and never turned back on. Not sure if its just the wire not connecting or what. There is only a small portion of the trace under the U1950 so I am guessing I am not getting a solid connection. Any thoughts on repair options?

Thanks G.Beard for the schematic! :D
 

Mac-N-Sauce

New member
so, this is driving me crazy! get the wire run, replace the capacitor C1950. Plug it in, get green and orange light. Fan spins, stops, then spins and stays on. Yea! Then I unplug it and take it to the computer to install, try it again just to be sure.... Get green and orange but no fan spin. Start checking U1950, have 3.42 v and nothing else. Check 3.3v its there, 1.05v its there, then all of a sudden they are both gone.

Is that U1950 finicky or is there some other issue?

HELP!
 

Mac-N-Sauce

New member
so, this is driving me crazy! get the wire run, replace the capacitor C1950. Plug it in, get green and orange light. Fan spins, stops, then spins and stays on. Yea! Then I unplug it and take it to the computer to install, try it again just to be sure.... Get green and orange but no fan spin. Start checking U1950, have 3.42 v and nothing else. Check 3.3v its there, 1.05v its there, then all of a sudden they are both gone. The voltage seems to be fluctuating.

Not understanding if the U1950 died again or is there something else causing the voltage fluctuation.
 

dukefawks

Administrator
I'm sorry it is impossible to diagnose something intermittent like this over the internet. When replacing U1950 something else is probably heated up and working again.
 

Mac-N-Sauce

New member
Ok, so I am back at this one again. Replaced u1950 and fans spin, put it back in the computer. It will power when plugged in. I can shut it off with power button, turn on with power button, but I get no boot, no screen, no keyboard caps lock. I know the track pad must be bad because it doesn't click. What could be keeping this thing from booting?
Thanks
 

Mac-N-Sauce

New member
Duke, yes PPVCC_SO_CPU is 1.857v, what Additional info can I give you? All the power rails seem to be present. No PPVOUT_SO_LCDBKLT
 
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Mac-N-Sauce

New member
NO it does not, strange though the track pad clicks. the cpu gets warm then gets real hot before the fan spins. i have a know good hard drive that gets really hot to the touch on the first chip out from the connector
 
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dukefawks

Administrator
No way to diagnose this more. If CPU Vcore is there it means POST is hanging somewhere. Most likely cause is corrosion under SMC/CPU or corroded trace/resistor. First area is always around SPI ROM and clock chip.
 
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