HP 15-eh0001nf with a start issue

[alloverme]

It could also be anything else, also check the HWPG line, it's the "power good" connected to several ICs, the EC receives the HWPG "power good" signal

I checked all lien when trying to power on, 0V at all output...

Check also 1.8V and 0.75V, there's 2 0.75V supplies, +0.75V and +0.75VS5, PU9200 and PU9201, the schematics says RT8068AZQW but the chip installed in both boards I have is a G2823D, may be pin compatible

I just find a Voltage in of 3.3V to the PU9200 and PU9201, very strange...

And i didnt get any short when i tested in short mode...

I re checked with my thermal cam and i didnt get any very obvious hot spot... no one up of 35°C

[m1ch43lzm]

I checked all lien when trying to power on, 0V at all output...

HWPG goes 3V when everything is powered on, that's the meaning of "power good"
if you get 0V at HWPG, that means that the power "is not good"
One of the following may be pulling down HWPG
- PU8700 (TPS51486)
- PU8600 (RT6316B), 3.3V supply, unlikely if the 3.3V are stable
- PU8601 (RT6318C), 5V supply, unlikely if the 5V are stable
- PU9201 (RT8068AZQW, but it can be a G2823D), 0.75VS5
- PU9200 (RT8068AZQW, but it can be a G2823D), 0.75V
- PU9300 (RT8068AZQW, but it can be a G2823D), 1.8VS5

The last things to turn on are the CPU and SOC voltages

I just find a Voltage in of 3.3V to the PU9200 and PU9201, very strange...

And i didnt get any short when i tested in short mode...

I re checked with my thermal cam and i didnt get any very obvious hot spot... no one up of 35°C

The input of those chips is 3.3V, the output is at the coils PL9200 and PL9201, should be 0.75V
1.8V you can find at pin 8 of the BIOS, after power on

What's the behaviour of the power LED and charger LED, is the power LED at the keyboard solid white, or is it pulsing quickly?
Same for the charger LED, should be solid white

Where was the liquid damage you mentioned on the first post?

[alloverme]

1.8V you can find at pin 8 of the BIOS, after power on

I have 1.8v at the bios during trying to power on (few second) like the 3.3v on PL9200

The input of those chips is 3.3V, the output is at the coils PL9200 and PL9201, should be 0.75V

I didnt get any output

What's the behaviour of the power LED and charger LED, is the power LED at the keyboard solid white, or is it pulsing quickly?

I get a video to get it easy to understand

I still get the PU8600 getting a bit hot when trying to power on but voltage are good... i tried to resolder it, still same thing

Where was the liquid damage you mentioned on the first post?

It was on the area in the picture (red circle), it was like a white humidity traces... not very obvious water damage...

[alloverme]

video and picture

[alloverme]

To explain the context, it came from a friend who mostely would like to get back his data (but if computer too, i'll be very happy) but there is a bitlocker on a disk and he didnt get any backup of the key.
We didnt find it on his microsoft account... so the only way is to get the pc up to log into it to access on data.

I'm thinking, is it possible to transfert the tpm to another working motherboard and start with it?

I was looking on the schematic of the motherboard at the tpm, it should me on U2205 and U5100 but those two IC are missing... i've look on the board and i cant find the tpm....

[alloverme]

I was looking on the schematic of the motherboard at the tpm, it should me on U2205 and U5100 but those two IC are missing... i've look on the board and i cant find the tpm....

The tpm is included in the processor....

[m1ch43lzm]

I saw the video, it may be a short somewhere else in the power on sequence, as the EC seems to be resetting, indicated by the charge port LED

The heat in PU8600 may be a partial short in the +3VPCU LDO output, I don't have thermal camera to check what's the "normal" heat of that chip

Measuring resistance to GND on the dead board at PC8615 (+3VPCU), i get 67.8Kohm

Check PU9600, it's a load switch, the input is 3.3v at pins 1-2 and 6-7 from PL8600
The outputs are labeled +3VSUS and +3V, check for shorts to GND at pins 13-14 and 8-9
Since the liquid was there, it's also suspect, either the chip itself or the outputs

Also PU9601 (this one is near the RAM slots), input +5VS5 at pins 1-2, output +5V at 13-14
Input +1.8VS5 at pins 6-7, output +1.8V at pins 8-9

The short could be there in the output side

There's no discrete TPM on the board, it's done inside the CPU/BIOS (AMD fTPM), if you copy the BIOS contents to a working board the TPM will be reset as it won't be paired with that specific CPU

For the bitlocker key
https://support.microsoft.com/en-us/...3-056f5ab347d6

It may also be stored in another account, if the laptop was setup by someone else, it could be in that account, or if your friend has a school/work MS account it may also be there