[SOLVED]820 3332 charging issuse

EJS

New member
820 3332 no liquid damage, light on magsafe very intermittently while the machine is assembled. I get green light on magsafe for a split second then it goes off when the board is pulled. I get votage starts at around 2v then drops rapidly on pins 1 & 2 @ j6900.
 

EJS

New member
On PP3v42 votage starts cycling from around .040v down to .010v

PPBUS voltage Cycles from around 1.5v to around 1v

I was getting 0v on ACIN ISL, R7010, R7011 are good, thought ISL may have been bad, I replaced, but no change
 

dukefawks

Administrator
112.7 Ohm is way to low. It is also too high for anything to heat up when injecting voltage. So this is going to be one of those boards that you will need to pull every component on 3V42 until you find it. Could be one of the tiny caps or even inside the board. Got time to waste?

You could go over the board with heat and cold spray to see if that 112 changes with temperature to narrow down the area where the bad component is.
 

EJS

New member
Duke when I measure the resistance of PP3v42 on a working board I get 108 Ohm, are you sure 112 is not good? Diode mode measurement is also nearly identical compared to my board with issues.
 

dukefawks

Administrator
I have no idea what you are measuring but on a known good board I have diode mode .330 and resistance 85K. You checking this with power applied or something?
 

EJS

New member
Our diode measurements are not that far off my .302 vs your .330. Your getting 85kohms, maybe i fucked up, and misread kiloohm instead oh Ohms, in that case we would not be that far off 112k vs 85k, but you said 112ohm is very low, I do not under stand how that would be anywhere close to low compared to 85k. Sorry Duke, I don't mean to be a pain in your ass, but I am very confused now.
 

EJS

New member
PP3V42 on my bad board, is extremely close to the same measurements taking off of a known good working board, and a donor board I have in my drawer. What gives....
 

EJS

New member
John, yes, we are both on the same page there. Duke said that 112ohm was way to low, but that is a much higher resistance then 85k. Anywho, PP3V42 on my bad board is 112kohms, sorry that was my fault for the bad info. .302v diode mode measurement and 112kohm resistance measurement. This is not too far off from the working board Duke is measuring on, and it is also even closer to a working board that I am measuring. PP3V42 does not seem to be short at all. Do you guys have any other advice?
 

EJS

New member
D6905
pin 1 .013v
pin 2 and 3 start at around 1.5v, voltage drops to around 1v, cycles back to around 7.5 then starts rapidly dropping again.

q6910
pins 1-3 .015v
pins 4-6 all look very similar to pins 2 and 3 on D6905
 

dukefawks

Administrator
So charger is shutting down. Q7080 is a common suspect. A good test for that is to plug in a battery that has charge in it so that PPBUS has power. Then measure on the magsafe connector if there is any voltage leaking through. Should be very close to 0V. Also check resistance on the magsafe connector, should be around 22K to GND.
 
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