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820-2849 green light no power no charge.

nate8organic

nate8organic

New member
got in a 820-2849 appears to have been cleaned. ppbus_g3h giving me 7.65-8.5v with charger plugged in. it bounces around slowly from 8-7 or 6v and then back up to 8 something. battery only is 1.5-2 volts. and it wont stay a steady voltage. checked the res on pin 27-28 and 17-18 on isl swapped the isl with a good one same thing. will not power from battery either. i have pp3v4_g3h. r5403 does not look good its giving 0 to .03 volts not that it should be putting out voltage necessary. im finding some corrostion and obvious liquid around the l6707 up the board d4610 right next to the smc. i did a smc by pass and nothing happened.

not sure if these symptoms have any obvious part / place to look or if need to just check every rail.

Thanks
Nate
 
nate8organic

nate8organic

New member
L7260 is flashing 0 volts to 3.3v back to 0 and just cycling this. reminds me of a blinking light. on and off consistently.

3V3S5_EN going from .34 to 1.2 to 3.4 and cycling through them over and over.
 
nate8organic

nate8organic

New member
pp3v42_g3h = 3.4v
pp3v3_s5 = 3.32v cycling to 0 and back up
pp3v3_s3 = 0.25v
pp3v3_s0 = 0.03v to 0.35v back and forth
pp5v_s5 = 4.28-2.98 jumping all around in between
pp5v_s3 = 0v
pp5v_s0 = 0v
pp5v_s3_isns_r = 0v

voltage drop to ground diode mode.
pp3v42_g3h = 0.093v
pp3v3_s5 = 0.40
pp3v3_s3 = 0.34
pp3v3_s0 = 0.28
pp5v_s5 = 0.404
pp5v_s3 = 0.39
pp5v_s0 = 0v
 
nate8organic

nate8organic

New member
i looked into everything pp5v_s0 is connected to and nothing is shorting to ground on that rail. is something not telling pp5v_s0 to turn on?
 
nate8organic

nate8organic

New member
u3402 is getting the hottest, r3452 is second hottest both up to 97 degrees u3402 gets up to 98.9 degrees. the q4590 was getting hot also but not as hot. The rest of the board is in low 80's..

I tried replacing them both and just pulling them off and checking res. nothing changed. also when injecting voltage trying to inject 5v and it was taking in about 1v up to 5 amps.

is this likely a break in the line? or something i missed here?

I have already gone over every part in the 5v_s0 line previously i replaced every part starting with the liquid damaged areas. i checked res after every part i pulled and nothing had changed.
 
D

dukefawks

Administrator
U3402 and R3452 are both on 3V line. No idea what you are doing....R3452 getting hot would suggest a short on L3404 side. But how they would heat up if injecting on 5V rail is a mystery to me.
 
nate8organic

nate8organic

New member
i am injecting voltage into the c7510, i also have no idea why i'm getting hot on 3v components.. i double checked again an def getting up to 100 degrees on the u3402 and it goes down it temp when im checking over the q4590 witch is on the 5v rail. i double check res to ground on the 3v rails and everything checks out good. really confused here how i'm reading higher temps on a 3v rail than on the 5v that im injecting into.. perhaps something else is getting hot and my temp gun cannot read correctly. its weird how i replaced every component and was not able to find the fault to ground. not sure how i can replace every part on the 5v_s0 line and have nothing change. maybe there is something i missed. it would have to be one of the components on the 5v_s0 rails right?
 
D

dukefawks

Administrator
So R3452 heating up. Tell me why it would not make sense to replace R3452. Also tell me why R3452 would be heating up and which components could be causing that. Also if you doubt your thermometer use your finger and/or alcohol.
 
nate8organic

nate8organic

New member
r3452 is a resistor so it should be good unless its fried up, not exactly sure of the correct answer.. i suppose the j3401 connector could be damaged, or c3421, c3422, c3420 could be bad, not sure why r3452 would be heating up unless somehow 5v was connected to that rail and that would be bad or somewhere there is a voltage leak in a gate, that is my guess not sure how logical it is but thats what i'm thinking..

i tried to feel by finger and dabbing alcohol but is rather hard to find the exact spot with these methods because the components are just not getting hot enough.
 
nate8organic

nate8organic

New member
sorry i didn't mean Celsius i meant Fahrenheit. the only question that i have is if i have a short on 5v_s0 and i remove every component on that rail shouldn't i have been able to find the short? unless its a break in the line right?
thanks for the help Duke.
 
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