HP CQ58: Power on; No Display

[speedypro]

Got here a HP CQ58 and as in title.

The thing that bothers me is that when you touch positive and negative of few caps I get a short (continuity test). Once CPU is removed, no short. This really puzzled me. Change CPU chip and same issue.

Not sure if the GPU chip is at fault with label "sjtnv" as it has no heatsink. Could it needs a reball? Reflow has no effect.

OR....I may need to remove all these caps to see if any is at fault?

Thanks!

[Pragmatiko]

Re: HP CQ58: Power on; No Display

Got here a HP CQ58 and as in title.

The thing that bothers me is that when you touch positive and negative of few caps I get a short (continuity test). Once CPU is removed, no short. This really puzzled me. Change CPU chip and same issue.

Not sure if the GPU chip is at fault with label "sjtnv" as it has no heatsink. Could it needs a reball? Reflow has no effect.

OR....I may need to remove all these caps to see if any is at fault?

Thanks!

CPU fan? start?

[speedypro]

Re: HP CQ58: Power on; No Display

CPU fan? start?

Yes. Spins for few seconds then stops.

[Pragmatiko]

Re: HP CQ58: Power on; No Display

i suggest you reflash bios before

[dj_ricoh]

Re: HP CQ58: Power on; No Display

You need to consider a reflow to.
First write down the values you measure and then reflow.
Start with a low reflow if it does change reflow it properly.
My opinion

[tiak]

Re: HP CQ58: Power on; No Display

Where is the caps? If they are around the CPU then it is normal. But you didn't told that the laptop remains on or turned off?
If this model of HP have Smart Fan technology (I think it have) it is normal too. (fan spins stops) For more details you can check the cpu and bga chips (bga chips that they are under the heatsink) temperature by touching them ,If any of them have a high temperature and still fan spins stops,then maybe it caused by I/O ic , because the one of the I/O duties is controlling the fan spins.
But before resold the chips or changing the I/O ic,I am agree with Pragmatiko,first check the backup battery voltage and if it was true then program the bios ic.
Sorry if I had fault in English writing or grammar and hope that was be useful for you.
Good Luck

[speedypro]

Re: HP CQ58: Power on; No Display

Where is the caps? If they are around the CPU then it is normal. But you didn't told that the laptop remains on or turned off?
If this model of HP have Smart Fan technology (I think it have) it is normal too. (fan spins stops) For more details you can check the cpu and bga chips (bga chips that they are under the heatsink) temperature by touching them ,If any of them have a high temperature and still fan spins stops,then maybe it caused by I/O ic , because the one of the I/O duties is controlling the fan spins.
But before resold the chips or changing the I/O ic,I am agree with Pragmatiko,first check the backup battery voltage and if it was true then program the bios ic.
Sorry if I had fault in English writing or grammar and hope that was be useful for you.
Good Luck

Caps are located beside CPU. backup battey reads 3v so thats ok.

Laptop stays on as in the power button light. Did a bios reflashed and still same thing. Nothing on display.

[tiak]

Re: HP CQ58: Power on; No Display

Ok,now what's about the temperature and fan spins? Cpu or bga chips gone hot but still fan spins stops? If answer is "yes" ,so first change I/O ic and if "no" first check with RGB port by a monitor and see you have display or not? now:
1-If you have display on RGB port then GPU chip is ok but it may loosed some connections with motherboard and you can first resold it and if still haven't display then you must reball this chip (if your laptop haven't GPU chip,it is in northbridge)
2-If you haven't display on RGB port,you must desolder the GPU chip,after desoldered it you check the SMD caps on it,if you see even 1 short cap on it so you must change GPU 100% ,and if not, you can reball it.

[speedypro]

Re: HP CQ58: Power on; No Display

Ok,now what's about the temperature and fan spins?

No temps; yes fan spins then stops (thats normal)

Cpu or bga chips gone hot but still fan spins stops?

No temps.

1-If you have display on RGB port then GPU chip is ok but it may loosed some connections with motherboard and you can first resold it and if still haven't display then you must reball this chip (if your laptop haven't GPU chip,it is in northbridge)
2-If you haven't display on RGB port,you must desolder the GPU chip,after desoldered it you check the SMD caps on it,if you see even 1 short cap on it so you must change GPU 100% ,and if not, you can reball it.

No display on vga. I was thinking a reball lol

[dj_ricoh]

Re: HP CQ58: Power on; No Display

No temps; yes fan spins then stops (thats normal)


No temps.



No display on vga. I was thinking a reball lol

did you manage to fix this notebook?

[speedypro]

Re: HP CQ58: Power on; No Display

did you manage to fix this notebook?

I need to remind myself to update posts lol. But yes, replacing gpu solved it, reballed never worked so I gues chip was bad in the first place.