820-3209 no video, no mouse

[MDY]

820-3209 no video, no light at mouse. I have 8.40 at PPBUS and 1.05 at L7630 PPCPUVCCIO_S0_REG
What is next to check?

 

[dukefawks]

CPU Vcore?

 

[MDY]

L7510 - 0V =PPVCORE_S0_CPU_REG
L7550 - 0V =PPVCORE_S0_AXG_REG
L7330 - 0V =PPDDR_S3_REG

No liquid damage

U7300

pin16 - 0.20V
pin17 - 0V

L7220 - 5V =PP5V_S3_REG
L7260 - 3.3V =PP3V3_S5_REG

R2530 - 0V
R2570 - 0V

 

[dukefawks]

Makes no sense, pin 16 on U7300 is the same enable as for 5V_S3 which is present.

 

[MDY]

I confirm u7300
pin16 - 0.20V
pin17 - 0V

as I can see 5V_S3 has another enable named: =P3V3S5_EN

and I miss: =DDRVTT_EN and =DDRREG_EN

Can you check again. I am wrong?

 

[dukefawks]

Look at where 5V_S3 is generated. P3V3S5_EN is enable for the 3V S5 rail. You say there is 5V on L7220 so P5VS3_EN_L which comes from Q7911. Q7911 is driven by the same bus as DDRREG_EN through R7911. So if there is 5V on L7220 the enable for DDRREG_EN must be high.

 

[MDY]

Sorry but I cannot find Q7911 at 820-3209

I started with page 7:

=PPBUS_G3H - 8.40V
=PP3V42_G3H_REG - 3.42V
=PPVRTC_G3_OUT 3.3V
=PP5V_S5_LDO - 5V
=PP5V_S3_REG - 5V
=PP5V_S0_FET - 5V
=PP3V3_S5_REG - 3.3V
=PP3V3_SUS_FET - 3.3V
=PP3V3_S3_FET - 3.3V
=PP1V8_S0_REG - 1.8V
=PPDDR_S3_REG - 0V (U7300 circuit)

As you can see =PPDDR_S3_REG - 0V is the first rail I miss from page 7.

U7300
Pin2 - 0V
pin12 - 5V
pin6 - 0V
pin16 - 0.2V
pin17 - 0V

R2810 pin1 - 3.3V
R2810 pin2 - 0V
=PP5V_S3_MEMRESET - 5V
R2802 - 5V

Finally I found that I miss PLT_RESET_L at Q2810 and this is the reason that I miss MEMVTT_EN => =DDRVTT_EN => which is enable to U7300

R2781 - 0V
R1125 - 0,13V

U2771
pin1 and pin5 - 3.3V
pin2,3,4 - 0V

Suspect U2771, U2780? Or CPU or PCH?

 

[dukefawks]

Could be anything. What happened to this board?

 

[MDY]

Nothing special. No liquid damage. Just one day stoped working.

 

[dukefawks]

Maybe BIOS, try another but backup the old.