820-00165 short

[wirelessplanet]

water damage 820-00165. U7100 has short on pin 6 CHGR_CELL

has no fan spin or orange light. whats best way to find the short on this guy?

 

[dukefawks]

Define short. Pin 6 is connected with 100Ohm to GND. Need the basic voltage measurements.

 

[wirelessplanet]

on diode mode its beeping

PPBUS_G3H = 1.57
PP3V42_G3H = .08
PP5V_S5 = 0v
PP3v3_S5 = 0v
PPVRTC_G3H = 0
U6100 Pin 8 = .03

 

[dukefawks]

Beep on diode mode != short!!

PP3V42_G3H = .08
I would call that problem number 1. Check voltages on D7005 and check for short on 3V42 rail.

 

[wirelessplanet]

D7005- starts at .8 and slowly rises to 1.6 and levels off there. Diode mode beeps on pp3v42_g3h rail. where would you recommend i inject power and check to see what gets hot?

 

[dukefawks]

D70005 has 3 pins.....
Diode mode beeping does not tell me anything, measure resistance.

 

[wirelessplanet]

sorry

d7005:
Pin 1: 1.57
Pin 2: .034
Pin 3: 1.46

PP3V42 resistance is: .5 ohms

 

[dukefawks]

That would be a short on 3V42, you know what to do.

 

[wirelessplanet]

Any place you would recommend to inject power or any cap is good?

 

[Gurmon]

Remove L7095, Then inject power into the pad that has a short. Start at 1V.

 

[wirelessplanet]

alright guys i have weird issue with PP3V42 line... when J9500 cable is plugged in which it was while originally testing, the resistance to ground was .5 ohms. While disconnected its 53k. i noticed this becuase i diconnected the magsafe from the board when injecting voltage and pp3v42 wasn't drawing any current. while that cable is connected it draws max current. weird thing is even with freeze test with cable connect nothing is heating up.

 

[dukefawks]

Are you plugging in the flatcbale the wrong way around? If not just get another IO board and cable.

 

[wirelessplanet]

tried with two different io cable with board. cable is on right way, and one of them was taken from a working computer... also noticed that the cable doesn't even have to be plugged into the io board. pp3v42 gets that way when cable i just plugged in by itself as soon as you plug in the flat cable.

 

[dukefawks]

Nothing else besides a connector issue then.

 

[wirelessplanet]

okay removed the j9500 port and fixed the problem. computer boots up now. do you know anyone who sells them or am i going to be stuck having to buy a bad board from china to steal it from.

 

[dukefawks]

Donor board is the only source I use.