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

[Dozer]

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

 

[Joesipaq]

What is the voltage from pin 1 and pin 2 to ground on R7965?

 

[dukefawks]

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]

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]

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

 

[Dozer]

i replaced it now and got my fan spin ! yeha

 

[Dozer]

thanks duke and josipaq for help

yes, pin 5 u7201 has now 3.3V

 

[Dozer]

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]

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

 

[Dozer]

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]

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