820-3115-B gets power, fan spin but shuts off after a moment?

[2informaticos]

Board should start and get voltages without RAM.
Check if all secondary voltages try to appear at least.
Be sure 3V42 and PPBUS_G3H are stable, as other voltages too.
Check for short on all S3 and S0 rails.
ALL_SYS_PWRGD appears?

 

[Hardwood T/S]

It does stay on in SMC bypass mode! I should remember to troubleshoot that when I see problems like these.
So I did a bit of further troubleshooting:

Tried multiple batteries before, all of which didn't work. Got a fresh new battery with a charge today tho to test, the machine boots just fine with a battery. No beeps, nothing awry, you get a chime and everything.
Just with AC, computer does not turn on fully. Also doesn't charge the battery, never changes from green.
How would I test resistance on those pins? They're way too small for my multimeter to reach accurately.

 

[2informaticos]

Get special SMD probes for your DMM; few bucks on eBay.

You can measure direct on the caps connected to these pins.
But this will not discard bad solders on the ISL6259.

 

[Hardwood T/S]

In resistance mode I checked C7020, since pad 1 was pin 27 and pad 2 was pin 28--I got 20ohms, but I'm guessing that's just the inherent resistance of the capacitor.
You think it's either a bad U7000 or bad SMC at this point?

I'll get those probes tho!

 

[2informaticos]

That is correct value.
I hope you have good contact from that cap to U7000.
Now check 17/18 too.

 

[Hardwood T/S]

Hard to get a good read on it, but my meter is saying 300ohms... seems a bit off. Should I try replacing C7050?

 

[2informaticos]

If no liquid signs, then should be one of R7051/52...

 

[Hardwood T/S]

Yeah, it was R7052!! Thanks a bunch guys! While I was taking it off I accidentally ripped the solder pad, so I ran a jumper wire. You guys are the best thanks again!! Now I just have to resolder a display connector since I had relegated this guy to parts earlier... lol