Quanta R22 (HP G6-1001sa) no power

[944longdrift]

Hi, I have an HP G6-1001sa with Quanta R22 motherboard DA0R22MB6D0
It has no power LED.
The 19V Vin is present.
There is no 3V or 5V, however neither of these two rails have shorts to ground.
Ive checked MOSFETS like PQ39,40,41,42 and no shorts.

My knowledge is limited so I am not sure what to check next?

Also does anyone have the boardview file for this motherboard?

Thank you!

[bicalov]

Re: Quanta R22 (HP G6-1001sa) no power

As you noticed in my thread, I burned my fingers on the R33 board, so although I would like to help out, I only can supply you with the schematics if needed.
In the end it came down to the PU8, which in your schematic is PU3. being the problem.
There the 3V and 5V are made..

[subroto]

Re: Quanta R22 (HP G6-1001sa) no power

Have you schematic?
I think it's the problem with 5v/3v3 IC.
You also have to check DCBATOUT voltage on these two MOSFET Rail.

[944longdrift]

Re: Quanta R22 (HP G6-1001sa) no power

Thanks guys, im going to order a new power IC and see if it works.

[944longdrift]

Re: Quanta R22 (HP G6-1001sa) no power

I just found pins 20 & 21 on PU3 are shorted together.
I guess that confirms this is where the fault lies?

[subroto]

Re: Quanta R22 (HP G6-1001sa) no power

Please mention the IC model.

[944longdrift]

Re: Quanta R22 (HP G6-1001sa) no power

its RT8223

[subroto]

Re: Quanta R22 (HP G6-1001sa) no power

It's a MOSFET Shorting problem in phase line 1. That's may be 5v line.
It seems that upper MOSFET short in 5v MOSFET rail which drain is connected to power line like 19V or something like that. The power is also known as DCBATOUT.

[944longdrift]

Re: Quanta R22 (HP G6-1001sa) no power

Hi,

I replaced PU3 (the 5V/3V source) and still dont have any 5V or 3V.
I also changed PQ40 and PQ42 which are mosfets on the 3V and 5V rails and no help.

I guess its not that surprising as there were not shorts to ground on either of those rails.

Has anyone got any idea what it could be?

thanks

[BlueMidnight]

Re: Quanta R22 (HP G6-1001sa) no power

For the upper MOSFETs, The voltage on the gate swings between PHASE1/2 (OFF state) and BOOT1/2 (ON state). So in the off state the UGATE1 is set to the PHASE1 voltage to turn the MOSFET off.

If just that one pair of pins are reading as shorted, that would be weird. But, if the other 3 corresponding pairs for the other 3 MOSFETs read as shorted, then that would make perfect sense since both outputs are off. Whatever way the IC changes those voltages internally, it should be consistent.

The best way to check a regulator IC like this:

1) Check all the output voltages. You're not getting the buck controller (switching) outputs, but are you getting the LDO outputs? (pins 8,17) Just make note of these voltages (or lack thereof) for now.

2) If any outputs are missing (the 2 switching outputs or the 2 LDO outputs), then check those lines for shorts to ground. If shorts are found then investigate. It looks like you checked this for the switching outputs already, but did you check the LDO outputs?

3) Check the supply voltage and enable signals. You already mentioned it's getting the 19V supply, but is it actually being told to turn on? (pins 1,6,13,18 should be high) Compare what it's being told to output and what it's actually outputting. If it's not receiving all the enable signals, then start checking those specific signals.

4) On an IC this small, just check all the remaining pin voltages to make sure you get what you expect. If everything is just what it should be (other than the missing output voltages), then you probably have a bad IC and/or MOSFETs. Since you've already replace those, hopefully you'll find the problem before you get all the way to the end of this step.