#1 Hp ZBook 17, MB: Compal LA-9371P, Rev: 1.0 No picture, missing "+VCC_CORE"
by matic • 15 June 2025, 13:13
Brand: Hp
Model: ZBook 17
Motherboard: Compal LA-9371P (VBK10), Rev.: 1.0
*******************************************************
Hello!
There was two completely burned capacitors - PC204 and PC205. They were burned to the point that they didn't cause a short circuit or low resistance to ground on the man power rail "B+". I think the laptop continued to work for some time after the capacitors burned out.
After replacing the capacitors, nothing changed - laptop reacts to the power button, all voltages on the coils are present (except the "+VCC_CORE"), there is no picture on the screen.
The CPU is completely cold, PCH gets a bit warm, the GPU slowly heating up.
Power consumption of the board is about 470mA and slowly increases to about 530mA (depending on the temperature of the GPU chip).
Resistance to ground on the "+VCC_CORE" (coils PL202, PL203, PL204) is about 3kΩ without the CPU and 48Ω with the CPU connected.
Voltages to ground on the CPU power supply controller chip PU201 (TPS51631A):
1 (SDIO)= 0V
2 (VDD)= 3.4V
3 (PGOOD)= 0V
4 (PWM3)= 1.7V (DC voltage without transitions)
5 (PWM2)= 1.7V (DC voltage without transitions)
6 (PWM1)= 1.7V (DC voltage without transitions)
7 (SKIP)= 5.0V
8 (VR_ON)= 3.4V
16 (VBAT)= 18.8V
27 (VREF)= 1.7V
28 (V5A)= 5.0V
30 (VR_HOT#)= 0V
31 (VCLK)= 0V
32 (ALERT#)= 0V
The data line connections between the CPU and CPU power supply controller chip PU201 (pins 1, 31, 32) are fine.
What has been done:
- Original CPU i7-4700MQ (SR15H) replaced with i5-4340M (SR1L0).
- Replaced CPU power supply controller chip PU201 (TPS51631A).
- Reflashed BIOS chip UH5 and VT memory chip U18.
I'm out of ideas, please help.
Model: ZBook 17
Motherboard: Compal LA-9371P (VBK10), Rev.: 1.0
*******************************************************
Hello!
There was two completely burned capacitors - PC204 and PC205. They were burned to the point that they didn't cause a short circuit or low resistance to ground on the man power rail "B+". I think the laptop continued to work for some time after the capacitors burned out.
After replacing the capacitors, nothing changed - laptop reacts to the power button, all voltages on the coils are present (except the "+VCC_CORE"), there is no picture on the screen.
The CPU is completely cold, PCH gets a bit warm, the GPU slowly heating up.
Power consumption of the board is about 470mA and slowly increases to about 530mA (depending on the temperature of the GPU chip).
Resistance to ground on the "+VCC_CORE" (coils PL202, PL203, PL204) is about 3kΩ without the CPU and 48Ω with the CPU connected.
Voltages to ground on the CPU power supply controller chip PU201 (TPS51631A):
1 (SDIO)= 0V
2 (VDD)= 3.4V
3 (PGOOD)= 0V
4 (PWM3)= 1.7V (DC voltage without transitions)
5 (PWM2)= 1.7V (DC voltage without transitions)
6 (PWM1)= 1.7V (DC voltage without transitions)
7 (SKIP)= 5.0V
8 (VR_ON)= 3.4V
16 (VBAT)= 18.8V
27 (VREF)= 1.7V
28 (V5A)= 5.0V
30 (VR_HOT#)= 0V
31 (VCLK)= 0V
32 (ALERT#)= 0V
The data line connections between the CPU and CPU power supply controller chip PU201 (pins 1, 31, 32) are fine.
What has been done:
- Original CPU i7-4700MQ (SR15H) replaced with i5-4340M (SR1L0).
- Replaced CPU power supply controller chip PU201 (TPS51631A).
- Reflashed BIOS chip UH5 and VT memory chip U18.
I'm out of ideas, please help.
