X550jx black screen but cpu heating up

[questore]

Re: X550jx black screen but cpu heating up

P_+3VSUS_CT2_10 and P_+3VA_EC_CT1_10 are both
5.5 volts I think this is not correct.

[questore]

Re: X550jx black screen but cpu heating up

Partial summary:
- GOOD NEW IS: Automatic power on when AC pluged in reason was a bad CMOS battery pin. When I have mesured the cmos battery right in the connector plus side it was only 0.3 volts. After bended the pin 3.05v presented and it won't start automaticaly when AC plugged in.
- BAD NEW IS: durring the last bios chip resoldering I have made something that made the laptop not responding to start button.

Next step is to find out why I cannot turn on the laptop.
I hear a high pitched noise when AC plugged in somewhere around the bios chip but can't realy tell where its coming from.
Inspecting with microscope... to be continued.

[questore]

Re: X550jx black screen but cpu heating up

Current Power sequence:

1 +3VA = 3.31
/ +5VA = 5.06v
2 PS_ON =3.31v
3 +3VA_EC =3.30v
4 EC_RST =3.27v
5 3VDSW_ON =3.27v
6 3VA_DSW_PWGD =3.37v
7 DPWROK_EC =0v

BIOS pins:
1 = 0.3v
2 = 2.84v
3 = 3.1v
4 = GRN 0v
5 = 0.55v
6 = 1.38v
7 = 3.1v
9 =3,09v

Now Help needed

[questore]

Re: X550jx black screen but cpu heating up

- Reflowed PCH since i did not shilded it when replaced BIOS chip.
- did a clean ME on the Original Bios bin file with "Intel Easy Clean Me"

Currently the laptop starts and capslock + numlock + power led lights up. (Still black screen)
Readings:

1 +3VA - 3.3v
/ +5VA - 5.05v
2 PS_ON - 3.3v
3 +3VA_EC - 3.3v
4 EC_RST - 3.27v
5 3VDSW_ON - 3.31v
6 3VA_DSW_PWGD - 3.3v
7 DPWROK_EC - 3.3v
8 ME_AC_PRESENT - 3.3v
9 PCH_SLPSUS# - 3.3v
10 5VSUS_ON - 3.3v
11 3VSUS_ON - 3.3v
12 5VSUS_PWRGD - 3.3v
13 +3VSUS_PWRGD - 3.1v
14 PM_RSMRST# - 3.3v
15 PCH_SUSACK# - 3.3v
16 ME_SuspwrDnAck - 3.3v
17 PWR_SW# - 3.3v
18 PM_PWRBTN# - 3.3v
19 PM_SUSC# - 3.36v
20 PM_SUSB# - 3.3v
21 SLP_A# - 3.3v
22 SUSC_EC# - 3.4v
23 SUSB_EC# - 3.3v
+1.2VS - 0v
24 1.35V_PWRGD - 3.3v
25 1.05VS_PWRGD - 3.3v
26 P_1.5VS_PWRGD - 3.3v
27 ALL_SYSTEM_PWRGD - 3.3v
28 +VCCIN - 1.75v
29 VRM_PWRGD - 3.3v
30 CORE_PWRGD - 3.35v
31 PM_PWROK - 3.3v
32 H_DRAM_PWRGD - 0.5v
33 DRAMPWROK - 2.45v
34 H_CPUPWRGD - 1.04v
35 SVID BUS - did not found any (VR_SVID_ALERT# 1.00v)
36 PM_SYSPWROK - 3.3v
37 BUF_PLT_RST# - 3.3v

After watching closely the integrated ram i noticed a high pitched sound is coming from around U1501 RAM chip.

So My guess is one of C1316, C1412, C1522, C1424, C1414, C1415 is partialy wrong.
Im going to remove them one by one and see if the high pitched sound disappears. If you have better idea then tell me please.

[questore]

Re: X550jx black screen but cpu heating up

Capacitor changed no result. Nothing changed.
I have no other idea
Anyone can help me why H_DRAM_PWRGD is low?

[questore]

Re: X550jx black screen but cpu heating up

I Have noticed something. H_DRAM_PWRGD is a signal that supposed to go from PCH to CPU. I'm I right?
So why does it not going to CPU? Both R0338 and R0341 are not existing Resistors.

[questore]

Re: X550jx black screen but cpu heating up

ACZ_SDOUT has a sort to ground.
I have to replace the PCH

[piernov]

Re: X550jx black screen but cpu heating up

What's the exact resistance to ground on ACZ_SDOUT?

[questore]

Re: X550jx black screen but cpu heating up

ok false alarm multimeters red wire was not plugged in correctly,sorry.

[questore]

Re: X550jx black screen but cpu heating up

I managed to get a good board and did some readings on resistors.

The main differences are:

R0347 - 10kohm ( 90Kohm on good board)
R0338 - 3.2Kohm (this was 1.7Kohm when i started the diag and 1.75Kohm on good board)
R0336 - 3.1Kohm (1.75 Kohm on good board)

Should I replace R0338 and R0336 with 1.8Kohm resistor?
What about R0347? Is iteven possible that a resistance is lowered when a resistor fails?

[questore]

Re: X550jx black screen but cpu heating up

I managed to get a good board and did some readings on resistors.

The main differences are:

R0347 - 10kohm ( 90Kohm on good board)
R0338 - 3.2Kohm (this was 1.7Kohm when i started the diag and 1.75Kohm on good board)
R0336 - 3.1Kohm (1.75 Kohm on good board)

Should I replace R0338 and R0336 with 1.8Kohm resistor?
What about R0347? Is iteven possible that a resistance is lowered when a resistor fails?

Changed battery on multimeter and Remeasured everything.
R0347 - 89.7Kohm on bad boards so its good.
R0338 - 3.75Kohm (1,75 on good board)
R0336 - 3.2Kohm (1.2 on good boad)

Thinking on what has changed durring the u0303 replacement.
It is possible that R0336 resistance is risen because of u0303 replacement heat was too high.

Since R0338 is a non existing resistor and it can be that it connected through a 0.5kohm resistor somewhere to R0336 and it raised because R0336 raised.

Ordered new 1.2Kohm resistor with sample book (30 days) be back withthe result when replaced R0336.

[questore]

Re: X550jx black screen but cpu heating up

Replaced R0336
Now Resistances are same as a good board.
Only thing that has changed is H_DRAM_PWRGD risen to 0.74v

Searched for more clues on the board and found that PU8501 nvidia power management has a short on pin #10
P_NVVDD_FBRTN_10 0v and short tu ground.
pins readings are:

1 P_NVVDD_BST1_30 - 5v for a sec then 4.37v
2 P_NVVDD_HG1_30 - 0v
3 P_NVVDD_EN_10 - 2.84v
4 P_NVVDD_PSI_10 - 3,36v
5 P_NVVDD_VID_10 - 1.5v
6 P_NVVDD_REFADJ_10 - 1v
7 P_NVVDD_REFIN_10 - 0,9v
8 P_NVVDD_VREF_10 - 2v
9 P_NVVDD_OCS_10 - 1.33v
10 P_NVVDD_FBRTN_10 0v (short to ground)
11 P_NVVDD_FB_10 - 0v
12 P_NVVDD_COMP_10 - 0v
13 P_NVVDD_PG_10 - 0v
14 P_NVVDD_HG2_30 - 0v
15 P_NVVDD_BST2_30 - 5v for a sec then 4.37v
16 P_NVVDD_LX2_30 - 0v
17 P_NVVDD_LG2_30 - 0vs
18 P_NVVDD_PVCC_20 - 5v
19 P_NVVDD_LG1_30 - 0v
20 P_NVVDD_LX1_30 - 0v

Seem like PU8501 is bad. Removing and lets see what happens

[questore]

Re: X550jx black screen but cpu heating up

Removed PU8501.
Ripped off half of the board with it cause of f*cking cheap heatgun.
Board is a Junk!
Thanks for the help!
Bye

[piernov]

Re: X550jx black screen but cpu heating up

P_NVVDD_FBRTN_10 is connected to ground so "short to ground" is expected.

[questore]

Re: X550jx black screen but cpu heating up

P_NVVDD_FBRTN_10 is connected to ground so "short to ground" is expected.

Thanks. I decided to make this board a "lab rat" and go on. I can't make it worse

[paulo66]

Re: X550jx black screen but cpu heating up

Thanks. I decided to make this board a "lab rat" and go on. I can't make it worse

Heh if you're like me I think you can! For instance, I've turned a board into a gooey mess just for trying several DIY fluxes.

[questore]

Re: X550jx black screen but cpu heating up

After Chip removed:

1 P_NVVDD_BST1_30 - 5v
2 P_NVVDD_HG1_30 - 0v
3 P_NVVDD_EN_10 - 3.05v
4 P_NVVDD_PSI_10 - 3,36v
5 P_NVVDD_VID_10 - rapidly rising and lowering from 0v-2v fastly
6 P_NVVDD_REFADJ_10 - 0v
7 P_NVVDD_REFIN_10 - 0v
8 P_NVVDD_VREF_10 - 0v
9 P_NVVDD_OCS_10 - 0v
10 P_NVVDD_FBRTN_10 0v (2 Ohm to ground)
11 P_NVVDD_FB_10 - 0v
12 P_NVVDD_COMP_10 - 0v
13 P_NVVDD_PG_10 - 0v
14 P_NVVDD_HG2_30 - 0v
15 P_NVVDD_BST2_30 - 0v
16 P_NVVDD_LX2_30 - constantly changing slowly between 0.7v-8v
17 P_NVVDD_LG2_30 - 0vs
18 P_NVVDD_PVCC_20 - 5v
19 P_NVVDD_LG1_30 - 0v
20 P_NVVDD_LX1_30 - 0v

[István Bornemissza]

Hello everyone. If possible, I would like to continue this topic because I have the same issue. I have thoroughly measured the power sequence, and everything seems fine, yet it exhibits the same symptoms as the machine in the initial post.
What I have as additional information is that there is no communication on the LPC lines. The PCH reads part of the BIOS from the flash IC. As far as I know, the crystals are working (25MHz crystal vs. 20MHz oscilloscope).
The PCH SUS_CLK# clock signal is present.
What could be worth investigating?