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820-4924-A Water damage, PPBUS_G3H fluctuate

2informaticos

2informaticos

Administrator
Staff member
$10 should be good too.
Is not multimeter problem; you have a problem on the board.
Check if voltage on big coils fluctuate too.

Also try to start in SMC bypass mode.
 
2informaticos

2informaticos

Administrator
Staff member
Does it start with both charger and battery connected?
You only need board, charger and battery.
Just connect an USB mouse and see if gets light.

You can measure direct on the caps close to pins 17/18 and 27/28; ISL6259, of course.
Be sure there are good traces to ISL...

Press power button, connect charger and maintain pressing 5-10s (SMC bypass).

BTW, search for "fine multimeter probe".
 
P

PatricF

New member
2informaticos said:
Does it start with both charger and battery connected?
You only need board, charger and battery.
Just connect an USB mouse and see if gets light.

You can measure direct on the caps close to pins 17/18 and 27/28; ISL6259, of course.
Be sure there are good traces to ISL...

Press power button, connect charger and maintain pressing 5-10s (SMC bypass).

BTW, search for "fine multimeter probe".
Click to expand...

If I do this correctly I get 5.2 Kohms on 17/18 and on 27/28 I get 20 ohms
I measured 17/18 on C7150 and 27/28 on C7120 if that is correct.

I plugged in the mouse and it lights up both when power+battery is connected and also lights up when only power or only battery connected. When only battery was connected it took a couple of seconds for it to light up.

Also tried SMC bypass but it wouldn't boot.
I never get any fanspin.
 
2informaticos

2informaticos

Administrator
Staff member
"If I do this correctly I get 5.2 Kohms on 17/18"
There is your problem; you should get 3 ohms aprox!
Check R7051/52 ans their traces to R7050.

"I never get any fanspin."
Fan will start after looong time on this machine; CPU must get hot first.

BTW, do NOT quote an entire post from few cm above...
 
P

PatricF

New member
Ah thanks.
I can't find R7051 and R7052 in boardview though. I can find R7050 and that is exactly where the corrosion happened.
I'm at work at the moment but I will check this when I get home tonight.
 
2informaticos

2informaticos

Administrator
Staff member
"Check R7051/52 ans their traces to R7050.
----------
I can't find R7051 and R7052"
Sorry, I should write R7151/52...
 
P

PatricF

New member
R7152 2.4 ohm
R7152 5.8 Kohm

So I'm guessing R7152 is shorted to ground/faulty here?

When trying to measure R7152 I just touched C7150 and it broke of. So I will need to get replacements for at least R7152 and C7150

Is it possible to order these parts online somewhere like Mouser or do I have to get a donor board for these parts?
 
J

JohnB8812

New member
Just replace them from a donor board so much easier. Replace R7152 and C7150 and this should be fine would be my guess
 
P

PatricF

New member
Thanks. I just ordered a donor board.
Will replacing these components fix the fluctuating voltage when the battery is not connected?
 
P

PatricF

New member
Great. Thank you for all you help.
I guess I can try to put wires there if it will work. Is it magnet wire that I should use or could I use any copper wire for this since it only a replacement for a component?
 
P

PatricF

New member
I bought a soldering iron and a hot air station to try and put wires in place of R7152. I ended up screwing up U7100 with the soldering iron and couldn't get the pins to connect to the board again and then I fucked up the pads on R7152 as well. The hot air station couldn't even get a resistor of the board so I guess it was a cheap piece of crap.

Thank you for all you help. To bad I suck at soldering so I couldn't fix it.
 
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