(347) 552-2258 [email protected]

820-3332 no power getting to board wine damaged

computercaverva

computercaverva

Member
I have a wine damaged 820-3332 board no major signs of corrosion, when plugged in we get green to orange light when mag safe 2 is plugged in, however would not power on or get a fan spin, measures PBBUS G3H was low voltage between 4.6v and tested found an issue in the isl6259 chip, I ordered a few new chips, when they came in I soldered the new one on and still no post or fan spin, after replacing the island the voltage increased from 4.6 to 5.81v, while troubleshooting multi meter touch down on board and made a small short and now there is no longer a green light or orange coming from the MagSafe charger and now the dc in voltage is .481v. I am not sure on what is going on or where to start trouble shooting here, I could use some pointers in the right direction!

thanks

Computer cave
 
larossmann

larossmann

Administrator
Staff member
Measure resistance of R7005. Measure resistance between pins 17/18 of the U7000, and 27/28 of the U7000. and obviously solder on a non-burned U7000. There's also a good chance of just bad soldering on the 2nd U7000.
 
TCRScircuit

TCRScircuit

Super Moderator
Staff member
If you had a green light and now you don't your soldering might be messed up... Make sure to push down on the chip while soldering... Once your done, Add some flux and then drag your iron across the pins.. Iv'e done it before where the ACOK pin wasn't soldered and resulted in no green light.
 
larossmann

larossmann

Administrator
Staff member
The no green light happened after measuring so he shorted something which killed the ISL and maybe R7005
 
computercaverva

computercaverva

Member
Just removed the U7000 replaced with a new chip, also removed all surrounding resistors and capacitors and replaced form donor board that had a bad Haswell CPU. Still no 3v42 and only ~0.5 coming in at the DC Jack, 4.1v on 17/18 of U7000, 21.1v pins 27/28 could it be that the SMC got shorted?
 
D

dukefawks

Administrator
"we were getting 17/18-24.1v , 27/28-21.3v"

Now look at the diagram and tell me which voltage is waaay to high and what could cause this. Hint PPBUS should be 12.6V
 
You must log in or register to reply here.
Top