[SOLVED]820-3330 Fan spins for a second then dies and repeats. PM_SLP_S4_L

[Therealkilometers]

So i have a 820-3330 board that will spin the fans for a second then turn off for a few seconds and repeat. I think it might be a dead SMC but not positive? Board has no liquid damage. Any help with thisi board would be great. Thanks

PM_SLP_S4_L - 3.3V when fan spins. 0 when not

PM_SYSRST_L - 3.3V when fan spins 0 when not - Comes from SMC
PM_PCH_SYS_PWROK - 0V all the time = SMC_DELAYED_PWRGD - 3.3V when fan spins 0 when not - Also From SMC
PM_S0_PGOOD = 0V all the time
CPUIMVP_PGOOD = always 0V
ALL_SYS_PWRGD - 3.3V when fan spins 0 when not
PM_PCH_PWROK - 3.3V when fan spins 0 when not
PM_RSMRST_L -Always 3.3v
PM_PWRBTN_L - Always 3.3V
SMC_ADAPTER_EN - Always 3.3v


PM_PWRBTN_L - Always 3.3v - Comes from SMC
SMC_PM_G2_EN - Always 3.3v
PP3V3_S5 - Always 3.3
PP5V_S5 - Always 5v
PP3V3_S4 - 3.3 When fan spens .6 when not
PP3V3_S3 - 3.3 V when fan spins. 0 when not
PP5V_S3 - 5V when fan spins. 0 when not
PP3V3_S3 - 3.3 when fan spins 0 when not
PP3v3_S0 - 3.3V when fan spins 0 when not

SMC Power - PP1V2_S5_SMC_VDDC - 1.2V when fan spins - .9 when fan off

RTC Clock Seems fine

 

[aprendiz]

85W original adapter???

 

[Therealkilometers]

Yes. I have tried with 2 different adapter that both work on other machines.

 

[aprendiz]

Check with oscilloscope if PP5V_S3 is coming high for a fraction of second

 

[dukefawks]

Vcore present on L7510?

 

[Therealkilometers]

Yes i do get PP5V_S3 going high for a second. But no Vcore on L7510. VVC and enable are both at U7400, But no CPUIMVP_UGATE1. Also Between L7510 and ground im only getting 1ohm. Is that normal for this board or is that to low

 

[dukefawks]

If this is not a BIOS issue this one is going to suck
Back up your old BIOS and try this one: https://drive.google.com/open?id=0By...WJfQll3MktCMWs
If this works then upload your original here to have the ME transferred. If it does not help you can put back the original.

 

[Therealkilometers]

I saw that yesterday on another post and went ahead and tried it but sadly we have the same results.

 

[dukefawks]

Then we have a problem
Ask owner for any history as how this could've happened.
Are you sure there was no liquid? R7402 and 7403 ok?

 

[Therealkilometers]

No liquid at all computer is in great shape. Looks well cared for. I did some more digging and removed L7510 and found that the CPU side has a .001 voltage drop to ground and that seams way to low. Im thinking its a bad CPU now. Is it fine to inject 1V on the CPU line to see if its something else that may be shorted?

 

[dukefawks]

These CPUS have very low resistance to GND so nothing strange there.
Again, ask the owner what happened, need some clues.

 

[Therealkilometers]

They claim it just died one day. No liquid or anything. from the looks of the board this looks to be true

 

[dukefawks]

What voltages are you getting on Y2605? No spikes over 1.6V?

 

[Therealkilometers]

No Title

Remember as louis says "The customer never lies" Found these little fuckers after noticing the PP3V3_ENET_FET was shorted to ground preventing me from having a 25Mhz System clock. After removing them the board works. On the plus side i now have a nice oscilloscope.

 

[dukefawks]

Not seeing much in that pic. Was it liquid that shorted a cap?

 

[Therealkilometers]

Yeah it was C7737 and C7738. Not positive that it was liquid as it really didn't look to green but it was a shorted cap that killed it. But its all working now. Thanks for the help Duke!!