820-2936b ppbus_g3h 15v

[Bouba148]

Hi Team,

I have a strange issue on that board:

First I had a lot of issue on that board and replaced many components because of no green light no PPBUS: C6999, U7000 etc....
Then I had PPBUS_G3H at 15V without green light so I replaced Q7030 and Q7035, when I took them out and mesured the resistance between Pin 5 and 1,2,3 I had almost a short: 1.2 Ohms for Q7030 and OL for Q7035 but if i compared with new one the same mesurements are around 40 Ohms.

Then I reflowed the U7000 area for the components to replace themself ( maybe bad soldering contact ).

Now I have the green light, the board is starting ( fan spinning ) BUT PPBUS_G3H is still 15.55V
Tried with 85W and 60W official chargers.

 

[2informaticos]

Still short D-S on Q7030; change it.
Be sure R/C7025 are OK and pin 24/U7000 is properly soldered.
You may need to change U7000 too...

 

[Bouba148]

Replaced once more Q7030 and U7000: PPBUS_G3H is 12.66V and PP3V42 is OK green light OK, fan spinning, just have to check the board back in the chassis and lcd because I plugged a speaker without RAM memory and it's not beeping .....and normaly it should beep without RAM Memory.
Thanks gracia merci so far 2 informaticos like usually......

 

[Bouba148]

Everything Fine and OK

Can close the topic

 

[2informaticos]

For the future, an USB mouse is good enough to detect an working board on the desk.
Sometime USB mouse can cheat you, so I recommend to use a pendrive with OSX installed.
Pendrive should have LED; if flashes, board is loading OSX...