Re: HP 840 G6 Laptop CRESCENT-6050A3022501-MB-A01(A1)

Is the 5VALW the one at the bottom left coil? The one reading 5.18V?

I can lift the coil and inject 1V, but there is already 5.18V here when plugged in, this would cause the faulty component to heat up more anyway? Or should I be looking for 5V at another coil?

I'll keep probing and see if anything changes, many thanks

Re: HP 840 G6 Laptop CRESCENT-6050A3022501-MB-A01(A1)

I'm going to try and find the EC chip on this board and hopefully a datasheet at least exists and I'll find the POWER OK signal

I've measured the resistances of the coils to ground and added them to the attachment. No shorts that I can see.

I also reapplied power and can confirm using a different multimeter the coils with 1.06V and 1.04V are still showing the same values....

Re: HP 840 G6 Laptop CRESCENT-6050A3022501-MB-A01(A1)

Thank you for your questions/help so far

Sephir0th - I really hope the PCH wasn't dying, but could well be the case,I don't know the history of the laptop.

However the shorted pins were supplied by the 12V rail so I'm hoping the PCH is okay....

app82 - As you say the 12V bus looks okay and I have checked for shorts and I can find none, the battery area sees okay too, both inductors are conducting.

To help I've added a picture and written on the voltages I can find. The...

Re: HP 840 G6 Laptop CRESCENT-6050A3022501-MB-A01(A1)

Thank you for your reply.

I've checked the BIOS battery and it is full at 3.08V, this is when connected to the board.

I don't think 10 watts is all that much, the power supply itself uses a few watts even when not connected and the fan at full consumes a few watts.

The only components which get slightly warm is an inductor next to the power jack and one near the battery area, this is after leaving the laptop for about half an hour just switching itself on and off.

Is...

Hello - this laptop originally as it had no power at all, battery was flat and wouldn't charge.

I traced the problem back to the connection to the screen, the positive supply for the LED backlight was shorted (not a direct but low resistance) to ground and was stopping the backlight from working and draining the battery quickly.

After taking these wires out of the connector, I connected them directly to a point on the PCB and then the backlight worked and the laptop booted up.

However an hour or so later something has happened to the laptop and now...

Re: New Members - please post your introductions here

Good evening everyone!

I've been involved with electrical and electronic engineering for over a decade and have fixed many TVs, videos, computers, chargers etc.

A few months ago I fixed a Vestel power supply and I found it very helpful reading through other comments about similar problems.

Now I have a difficult problem with a laptop!