HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

[A1yn88]

Hello everyone.
An HP Pavilion - 15-bc414nq laptop that restarts every second came into service. I took it apart and found 3 burnt capacitors on the 19v line. I took them down. Now the laptop starts and restarts once after 20 seconds, after the restart it stays for 20 seconds and then stops.
I noticed that I have 0V on Bios pin 5 / 6 (PCH_SPI1_SI_R / PCH_SPI1_CLK_R) and I don't know if it's normal or if I should have something.
There is another coil near the processor that is 0V, but it is not the exact diagram for this laptop and I don't know what exactly should be there.
I have attached some pictures, maybe someone can help me.
Thank you.

[mon2]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

Can you post or link the schematic in the schematic forum?

Check if the same SPI flash is being powered.

On the board, the PCH is the SPI bus master so the PCH is driving the PCH_SPI1_CLK_R line.

Confirm the presence and integrity of the series resistors on the same lines of the SPI bus interface. Check the voltage on each side of the SPI resistors.

[A1yn88]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

Can you post or link the schematic in the schematic forum?

Check if the same SPI flash is being powered.

On the board, the PCH is the SPI bus master so the PCH is driving the PCH_SPI1_CLK_R line.

Confirm the presence and integrity of the series resistors on the same lines of the SPI bus interface. Check the voltage on each side of the SPI resistors.

Here is what I found out about the schematic or boadview.

[mon2]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

Please post these files in the schematic section (not here).

[A1yn88]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

The resistors are good. I saw that pin 5 from the BIOS reaches ITE IT8987E in pin 102 and pin 6 in 105.
If I measure when it starts it is for a fraction of a second approx 2V on each pin, after which it disappears.

[mon2]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

Perhaps a corrupt bios? Do you see pulsing on the chip select (PCH_SPI_CS0#) of this bios? Some data has to be exchanged to confirm if it is a corrupt bios.

[A1yn88]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

Perhaps a corrupt bios?

I have change the MAIN Bios, may be the EC, but i don't have a progremmer for EC. I read somewhere that a new ITE can be installed and programmed from the MAIN Bios, automatically.

[mon2]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

Wait on feedback from others with experience on the bios topic. Do check to be sure there is not a shorted power rail which may offer the same symptoms. That is, the PCH is attempting an access to the SPI bios but then a shorted power rail shuts down the entire boot process.

Remove all power -> meter in resistance mode -> check the resistance to ground of each and every coil which is linked to a local buck mode switching power supply. Some rails will be with a low resistance, by design.

[Vesko356]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

Here is what I found out about the schematic or boadview.

Please follow mon2's advise, all schematics and BV should be posted only at Schematics section:
https://www.badcaps.net/forum/forumdisplay.php?f=41

If the schematic is missing in this section, please upload it and give a link to it.

.

[A1yn88]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

Please follow mon2's advise, all schematics and BV should be posted only at Schematics section:
https://www.badcaps.net/forum/forumdisplay.php?f=41

If the schematic is missing in this section, please upload it and give a link to it.

.

It was from this site. And is not for this motherboard. This is what I found approx for my motherboard.

[A1yn88]

Re: HP Pavilion - 15-bc414nq DAG35MMB8C1 REV:C restart loop

IT working!!! I have changed the ITE.