HP Pavilion 17-ab091ms - white charging light, but no power

[tahc81]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

I think I'm fine.

Still need to check how to do all that.
But if a broken BIOS cannot result in a short, so I don't see a point on trying to reflash it. Or did I get it wrong?

I think the fried BIOS chip is like a Yeti = nobody ever seen him Generally speaking, BIOS issue usually stands for corrupted data preventing PC from starting. If you see BIOS shorted (pins 4 & 8), it's usually something else shorted, not the BIOS chip itself. 3V3 and 1V8 as well are connected to other components, and it can vary from single capacitor or diode to a mosfet or CPU/chipset. When 3V3 is not present and shorted, I usually using voltage injection and checking for the heat spot to identify the short.

Note: if there's a short on 3V3, you will fail to read/write BIOS chip

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

That reminded me that the board is shorted-Where do you find it is shorted??

https://www.badcaps.net/forum/showpo...19&postcount=3

Maybe an issue with the 1V1 line, as both this caps should have 1V1 on it?

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

I think the fried BIOS chip is like a Yeti = nobody ever seen him Generally speaking, BIOS issue usually stands for corrupted data preventing PC from starting. If you see BIOS shorted (pins 4 & 8), it's usually something else shorted, not the BIOS chip itself. 3V3 and 1V8 as well are connected to other components, and it can vary from single capacitor or diode to a mosfet or CPU/chipset. When 3V3 is not present and shorted, I usually using voltage injection and checking for the heat spot to identify the short.

Note: if there's a short on 3V3, you will fail to read/write BIOS chip

I will have a voltage injection tool tomorrow. So for now I was trying to find the issue with testing.
But it does not seem too easy.

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Just to add...
I was watching some BIOS reflash videos and the guy mentioned that there should be 3V on pin 8.
According to the board view I have it should, indeed. And ground on pin 4.
I could find ground on pin 4 but on pin 8 I get only 0.08V.

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Well... I got the voltage injector.
Injected 1.2V on the pad from one of the caps I removed. The mobo is drawing 0.076 amps, which seems very low.
I could not feel anything hot on the board.
Should I up the voltage to 1.8V, which is the next step on the device?

[mcplslg123]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Going by your thread from beginning, i still could'nt understand which "SHORT" you are talking about. can you please elaborate where do you find short??

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Going by your thread from beginning, i still could'nt understand which "SHORT" you are talking about. can you please elaborate where do you find short??

Initialy, on these caps marked in red and green.
On the board view I have they could be PC2012/PC2013/PC2014 and PC6009/PC6010.



After cleaning this in the back of the board,



the ones in red are not shorting to ground anymore. The ones in green were still and I removed them. The pads are still shorting to ground.

And, after all these days tinkering with the board, I can find lots of caps shorting, including all those around the CPU area, in the back of the board.

[mcplslg123]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

I dont think its shorted. What is the exact resistance on those caps?? Remember, caps will show very low resistance near cpu/gpu area and even lower with onboard soc. Resistance above a couple of Ohms is not likely shorted.

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

I dont think its shorted. What is the exact resistance on those caps?? Remember, caps will show very low resistance near cpu/gpu area and even lower with onboard soc. Resistance above a couple of Ohms is not likely shorted.

Ok. Got it.
Those around CPU are like 1.8k ohms.
So, I'm back to squase zero. Almost. :p

[mcplslg123]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Btw, Did you checked LID Switch??

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Btw, Did you checked LID Switch??

I mentioned it here (at least maybe it is this)
https://www.badcaps.net/forum/showpo...3&postcount=12
How should I exactly check it?

If you mean a specific LID switch board, this model does not seem to have it.

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

If I wanted to try turning it on without the daughter board, where the power button is, which pins on the daughter board connector I should short?

[mcplslg123]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Pin#16 to GND should turn it on. Red probe should be on GND and you need to touch pin16 with black probe.

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Pin#16 to GND should turn it on. Red probe should be on GND and you need to touch pin16 with black probe.

Hmmm white light just went down and on again.
CPU not getting hot.

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Please note that BIOS chip is 1.8V device, so you'd need 1.8V SPI adapter. And no, incorrect/broken BIOS image can't cause short on power rail. If the EC BIOS is a part of it, it could make some other issues, but at least 3.3V is completely independent of BIOS and EC.

Hi. I was re-reading the thread, to check if I missed something or had a clue on what to try next, and I think the BIOS on it is 3.3V, not 1.8V.
I even found it for sale stating 3.3V.

[mcplslg123]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Hmmm white light just went down and on again.
CPU not getting hot.

White light at dc jack blinks when you try to turn it on-Right?? That most probably indicates problem with AC-Adapter not properly recognised. Try with another HP Original adapter, if possible, check ADP_ID circuit thoroughly. I Think this model may require a 90W charger.

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

White light at dc jack blinks when you try to turn it on-Right?? That most probably indicates problem with AC-Adapter not properly recognised. Try with another HP Original adapter, if possible, check ADP_ID circuit thoroughly. I Think this model may require a 90W charger.

No, it does not blink. It's a solid white light.
The original charger is a 120W one.

[mcplslg123]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

Hmmm white light just went down and on again.
CPU not getting hot.

What you wrote here, indicates AD_ID problem. This is what i mean by blinking at dc jack. Solid white light when plugged in, try to trigger, light goes down and back.

[BMCappelletti]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

What you wrote here, indicates AD_ID problem. This is what i mean by blinking at dc jack. Solid white light when plugged in, try to trigger, light goes down and back.

Got it.
I tried just once. Hope I shorted the right pins. But I can try to replicate it again.
But, if it is what you say, what should I do next?

[mcplslg123]

Re: HP Pavilion 17-ab091ms - white charging light, but no power

First, confirm what i have described. If it's so then AD_ID needs to be checked.