[SOLVED]820-3024 - liquid damaged, POST but sensors failed.

[Alan.L]

AXG sensor failed, - u7400 looks clean. Q7550 area looks clean

CPU highside sensor failed -

Pbus sensor error - some liquid got here. i've replaced Q5300, no change.

 

[2andrewd]

Look close at u5450, u5400.

 

[Alan.L]

R5400 has been replaced initially, would make sense to replace U5400. i dont have U5400 from 3023 donor board in-stock. Can i use one from 3435 donor board?

found a small green shit on u5400. so i've replaced.

AXG sensor is fixed.


i bet its SMC, i need to replace. reflowed but no change.

 

[2andrewd]

Idk off top, more likely than not. Check the part numbers on schematic against each other.

See what Duke has to say before replacing, it may be something simple.

 

[dukefawks]

VP0R will be corrosion on Q5300.
VC1R is not common, measure on R5320. Check in hardware profile to see what the limits of the sensor are, will give a clue as where to look.

 

[Alan.L]

replaced Q5300, still no change. i'll try again.

 

[Alan.L]

thank you, i didn't know i can read voltages in Hardware profile.



This board:

has to be smc.

A Good known working board that i've fixed:

 

[dukefawks]

Are all voltage reading slightly low? Could be the reference voltage for the SMC is off. AVREF comes from U5010.

 

[Alan.L]

changed U5010, made no differences.

is it normal for this model. it always power on with a charged battery then plug a charger?

ppbus_g3h:

8.38v with charger, no battery
7.63v with battery and charger.



can i use a SMC from 3023 board? i ordered some 3024 donor boards but will take a week to arrive.

 

[dukefawks]

Why do you change U5010 without verifying AVREF?

 

[Alan.L]

sorry duke, i meant i've changed Q7630. as this part looked like liquid got there.

i havent measure U5010 yet. i do it in the morning.

but i remember i've changed this part before i made this thread because it got corroded .

 

[Alan.L]

U5010

pin1 - 3.418v
​​​​​​​pin3 - 3.418v
​​​​​​​pin4 - 2.5v
​​​​​​​pin5 - 3.387v
pin6 - 3.402v
​​​​​​​pin7 - 3.415v
pin8 - 3.296v


U5010 and U7941 was corroded when i got the board. they both have been replaced before.

 

[dukefawks]

What is the actual VP0R voltage when measured on the board? Check the same with VD0R. If all voltages are reported low by the SMC it would indicate a AVREF issue.

 

[Alan.L]

where do you measure VP0R on the board ?

is it Q5300?

pin2 3.32v
pin3, 8.37v
pin4, 8.37v
pin5 4.166v
pin6 0.1v

VD0R will be Q5310 right?

 

[dukefawks]

pin3 or 4 on both Q5300/10. Compare to what SMC is reporting in ASD.

 

[Alan.L]

with battery:

Q5300
pin3 6.82v

Q5310
pin3 - 0v

ASD hardware profile:
VP0R - 6.916v
VD0R - 0v




with charger & battery:


Q5300
pin3 7.80v

Q5310
pin3 - 16.40v

ASD hardware profile:
VP0R - 7.90v
VD0R - 16.40v

 

[dukefawks]

Uhm, isn't this a very discharged or dead battery?

 

[Alan.L]

mm battery was at 20%, now i've charged up fully.



just tried ASD EFI, all passed. why?? how can a low battery caused these two sensor errors?

 

[dukefawks]

Dunno, but a totally discharged battery will pull VP0R under the low limit. Case closed.