HP Laptop TPN-C125 15-ac181no dead no lights no fans

[dicky96]

Hi guys
Sorry I am, no expert on laptops, I have fixed a couple before with some help from this forum but that's about it.

I have this HP TPN-C125 here and it's just plain dead

I tried with and without the battery

The PSU is supplying 19.5V, I can measure this voltage across the cable that comes from the jack socket in the laptop to the mainboard so I know voltage is getting as far as the main board.

There is a little LED on the power button but it does not light up. The fan does not even try to spin for an instance when power is applied.

With the battery fitted, measuring across the longer terminal pins either side of the battery connector I read 0.2V when the 19V power supply is off and 0.4V when the power supply is on.

There is no short circuit across the battery pins.

I tried disconnecting the HDD power lead - no difference.

I'm a bit uncertain how to diagnose this fault.

Richard

[dicky96]

Re: HP Laptop TPN-C125 15-ac181no dead no lights no fans

I also have disconnected the ribbons to the keyboard, mouse pad, usb connector board and anything else i could see to disconnect

Rich

[dicky96]

Re: HP Laptop TPN-C125 15-ac181no dead no lights no fans

Does anyone have a schematic for this laptop please?

I have a short circuit to ground from the centre pin of PD2 which is an SMD diode? device is marked VC051 or VCO51 but I can't find a datasheet. 19V comes into the top pin of the device (as seen in the attached pic) and is present

This short is also on the Drain (I think) of PQ206 marked GA5N15 but again I couldn't find a datasheet. There is no short on what I assume is the source of PQ206

Same short from +ve of electrolytic cap PC78

Cheers
Rich

[meritosari]

Re: HP Laptop TPN-C125 15-ac181no dead no lights no fans

Does anyone have a schematic for this laptop please?

I have a short circuit to ground from the centre pin of PD2 which is an SMD diode? device is marked VC051 or VCO51 but I can't find a datasheet. 19V comes into the top pin of the device (as seen in the attached pic) and is present

The centre of pin PD2 is GND, see datasheet and schematic as reference.
https://www.badcaps.net/forum/attach...7&d=1502147827

This short is also on the Drain (I think) of PQ206 marked GA5N15 but again I couldn't find a datasheet. There is no short on what I assume is the source of PQ206

Check Alpha Omega AON7408 datasheet.

Same short from +ve of electrolytic cap PC78

That's mean you have shorted on B+ (19V rails for system). Use DC bench Supply, at first inject with low voltage only 1V, then find what component be hot or warm.