820-2915 dont start, green/orange light is there

Dozer

Member
hi, i am just have a problem with this board, no fan spin


PP5V_S3 is 5.0V
PP3V§_S3 is 3.3V

S5_PWRGD is 3.4V
PM_SLP_S4_L 3.3V

P5VS3_PGOOD 0V

red on ground i found there(pin 5) in diode mode 0.091, a good one has there 0.521

i replaced the u7201, no fan spin, on pin 5 now is about 0.521, should be ok.

I replaced a second time to be shure but still the same, pin 5 ok but 0V

i removed R7965 (value is ok) but still u7201 pin 5 0V

R7247, R7256, R7249, R7220, R7221, R7260,R7261, R7216, R7246, R7206, values ok

VREG 5, VREG 3 is good


need some help please
 

dukefawks

Administrator
5V and 3V were present....why did you touch U7201?????

P5VS3_PGOOD is connected to many other power good signals. So another rail is missing and pulling it down.
 

Dozer

Member
R7965 pin 1 has 0.06V and pin2 has 0.06V


I touched u7201 because pin5 measured to ground in diode mode was only 0.091 and compared with a good one should be 0.521
after replacing pin 5 had 0.521 as well

5V and 3V are still present. I found out that 5V_S0 and 3.3V_S0 are present but still no fan spin




PP3V3_SUS 3.3V
PP5V_S0 5.0V
PP3V3_S0 3.3V
PP1V8_S0 1,8V
PP1V8_S0_CPU_VCCPLL_R 1.8V
PP1V5_S0 1.5V

PP0V75_S0_DDRVTT 0V

PP1V2_S0 1.22V
PP1V05_SUS 1.07V
PP1V05_S0 1.06V
PP3V3_S0GPU 3.19V
PP1V8_GPUIFPX 1.81V
PP1V8_S0GPU_ISNS 1.81V
PP1V5_GPU_REG 1.51V
PP1V5_S0GPU_ISNS 1.51V
PP1V0_S0GPU 1.02V
PP1V0_S0GPU_ISNS 1.02V
PPVCORE_GPU 1.13V

PPVCORE_S0_CPU 0V
PPVCORE_S0_AXG 0V

PP1V5_S3_CPU_VCCDQ 1.5V
PP1V05_S0_CPU_VCCPQE 1.07V

PPVCCSA_S0_REG 0V
 

Dozer

Member
No Title

i checked PPVCCSA_S0_REG and it has (diode mode) it has only 0.007, a good board has about 0.030

looked around and found that
 

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Dozer

Member
so wht is PPVCCSA_S0_REG for? of course cpu power. but is it for the core? is it the first power on cpu?
 

dukefawks

Administrator
CPU will be dead probably. You could replace the damaged FET and also replace the controller chip! Maybe you get lucky.
 

Dozer

Member
i replaced the cap and got fan spin and a working machine. is it nevertheless necessary to replaye the fet and the controller chip ?
 

smiba

New member
If the system passes a full ASD test and works without issues there is no reason to replace this
 
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