[SOLVED]820-3115-b , green light, does not turn on , P3V3S5_EN_L missing

[turbo]

this 3115-b board had little water damage , now fully cleaned,

5v and 3.3v is missing,

on Q7221 pin5 P3V3S5_EN_L is missing , but there is P5VS3_EN_L on pin2


P3V3S5_EN_L taking me to to U7941


U7941 here is pin voltage

1=3.49v
2=3.49v
3=3.47v
4=0v


5=0v
6=3.34v
7=0v
8=3.47

any idea why P3V3S5_EN_L missing??

 

[dukefawks]

P3V3S5_EN_L is supposed to be missing hence the L. So either a short on 3V3 bus or bad 51125 or corroded trace around it.

 

[turbo]

here is the voltage on u7200 pin
pin 1 is 0v !!!! and pin 9-7.70v


1. 0
2. 0
3.2v
4. 3.34v
5. 2v
6. 0.78v
7. 3.34v
8 3.34v
9. 7.70v
10. 3.34v
11. 3.34v
12 0v
13. 3.47v
14. 2v
15 0v
16. 12.6v
17 5v
18 un coneected

 

[dukefawks]

You say 3V3 is missing yet there is 3V3 on pin 11. This makes no sense.

 

[turbo]

ya i just notice that too, but 5v missing for sure ,

 

[arghhh]

P3V3S5_EN_L is supposed to be missing hence the L. So either a short on 3V3 bus or bad 51125 or corroded trace around it.

Sorry to hijack this, but question about the _L thing: Isn't PM_SLP_S4_L supposed to be high? Is it just a misnomer?

 

[dukefawks]

I need some dependable measurements. Not this crap you are feeding me now.

Where was the liquid damage? Voltages on RTC circuit R18001/2/3? Checked all coils for shorts?

 

[dukefawks]

SLP is sleep so is low in "sleep" or inactive. So out of sleep it should be high.

 

[turbo]

No Title

Pls chk the pic , water damage was around that area

rtc circuit is which one ,

 

[turbo]

I changed the 51125 still no result , you are right problem is some where else I guess

 

[dukefawks]

Miniature pictures, useless.

 

[turbo]

No Title

 

[turbo]

how ot upload full size pic !!! or any email i can sen you pic ?

 

[SMMRepair]

Upload to imgur, post link.

 

[turbo]

http://imgur.com/01MUdFp
http://imgur.com/KqQAHgE

 

[turbo]

Miniature pictures, useless.

i uploded some new pic with link, pls chk link

 

[dukefawks]

Pictures show nothing. You did not answer my previous questions, it seems you know better.

 

[turbo]

also here is no good one and good one u7200


fixing ------------------------------good one

0	1.15
0	2
2v	2
3.34v	same
2v	same
0.78v	same
3.34v	same
3.34v	same
7.70v	same
3.34v	same
3.34v	same
0v	0.63
3.47v	same
2v	same
0v	same
12.6v	same
5v	same
18 un coneected
0	0.061
0	5
0	5.1
4.4	9.81
0	3.3
0	5

 

[dukefawks]

I didn't ask you this and this is all useless info.

 

[turbo]

Any help from any one ?????