Laptop Dead except for the lights and fans.

[I_am_learning]

I had this compaq presario v3500 model laptop running fine. But yesterday, It suddenly won't start. When I press the power button, the fan runs, the power leds (on the motherboard and on the power button) lights continuously and nothing happens. It remains like that for eternity. .
Doing 'HARD RESET' don't solve the problem, neither does playing with RAM. In fact, even when I remove RAM and Harddisk, the poor thing can't even complain (no blinks or beeps).
No its not display problem, even when leaving it for hours, the CPU is dead cold.
(if it were only the display then, cpu should have been quite hot (or atleast warm) becasue of doing *some* work)

It had similar issue few months back, at which case, cleaning the mobo with petrol and giving a full day sunbath healed it. It won't do now.

Help please?
(I have all the tools and skills to replace ICs or measure voltages on the mobo if needed.)

[gabik111]

Re: Laptop Dead except for the lights and fans.

When you removing RAM usually system won't start .
Try to reseat CPU but better if you got diferrent CPU to see if this is not dead CPU. Also do the same with RAM.
First get the schematic then check 3.3V and 5V or Vcore to make sure you got all voltage.

[ala_borbe]

Re: Laptop Dead except for the lights and fans.

if it has nvidia graphics or chipset so some research and then do reflow like on dv6000/dv9000 series of HP

[sasser]

Re: Laptop Dead except for the lights and fans.

reball or reflow your nvidia graphics. set your hot air blower at 230c the reflow about 3minutes. try start your machine

[I_am_learning]

Re: Laptop Dead except for the lights and fans.

Thank you all.
Yes, reflowing (or reballing?)the nvidia GPU seems like the only solution. I checked the Vcc_core voltage and it was 1.5Volts.
What I am wondering is, in the schematics, I can see that the Power led can *only* glow when the GPU wants it. (i.e. it is connected to one of the GPU pin, or atleast controlled by it.) So, if GPU was disconnected from the pads, then the LED shouldn't have glown either.
But, maybe only some of the GPU pins are disconnected, and those that are required to glow the Led are still connected.
I will try reflowing and let you people hear, what happened.

[sasser]

Re: Laptop Dead except for the lights and fans.

not at all led power is glow eiter the bga ok or not coz the led power when the motherboard startup power is enough and u got 18.5 with no drop. The led is not the indicator the balls under gpu its ok. Try reflow n tell we all what happen.

[I_am_learning]

Re: Laptop Dead except for the lights and fans.

Rflow and Kaboom!
It won't even light the LEDs now. Completely Dead.
Someone please help.

[RJARRRPCGP]

Re: Laptop Dead except for the lights and fans.

Did a cap pop on you?

[DerStrom8]

Re: Laptop Dead except for the lights and fans.

Funny you should mention this. I just started a thread here today regarding a similar problem. I haven't yet got around to reflowing, but have been doing research on the technique for a while. When you do the reflow, it's VERY important that you protect sensitive components (electrolytic caps, for example) with aluminum foil at the very least, if not remove them entirely. It's also important that you set the board up an inch or two to ensure airflow so that you don't fry the underside of your board. Finally, make sure you remove all the important modules that can be removed safely (CPU especially). You also need to remove plastic parts, wires/cables, and labels from the board. All that can be left there are the components and board.

If nothing works now I'd have to say you're pretty much screwed. I'm sorry to say it. Your only chance would be if it was just the electrolytics that are damaged. They are easily replaced. But if it's something inside one of the chips, or a fried SMD resistor or capacitor somewhere, it'll take a LONG time to troubleshoot. You'd be lucky if you can even find it.

So the question now is, how did you reflow your board? What precautionary measures did you take to protect the sensitive parts?

I wish you all the best.
Regards,
Matt

[RJARRRPCGP]

Re: Laptop Dead except for the lights and fans.

Symptoms remind me of when I cracked my T-bird 1.3 core when putting the heatsink on.

Had to pop my T-bird 900 back in!

(October 13, 2002)

[I_am_learning]

Re: Laptop Dead except for the lights and fans.

Funny you should mention this. I just started a thread here today regarding a similar problem. I haven't yet got around to reflowing, but have been doing research on the technique for a while. When you do the reflow, it's VERY important that you protect sensitive components (electrolytic caps, for example) with aluminum foil at the very least, if not remove them entirely. It's also important that you set the board up an inch or two to ensure airflow so that you don't fry the underside of your board. Finally, make sure you remove all the important modules that can be removed safely (CPU especially). You also need to remove plastic parts, wires/cables, and labels from the board. All that can be left there are the components and board.

If nothing works now I'd have to say you're pretty much screwed. I'm sorry to say it. Your only chance would be if it was just the electrolytics that are damaged. They are easily replaced. But if it's something inside one of the chips, or a fried SMD resistor or capacitor somewhere, it'll take a LONG time to troubleshoot. You'd be lucky if you can even find it.

So the question now is, how did you reflow your board? What precautionary measures did you take to protect the sensitive parts?

I wish you all the best.
Regards,
Matt

Well, I did remove all removable parts, including CPU. I did use aluminum foil to protect other parts. I practiced reflowing in a scrap desktop mother board before trying on this one.
There were like three small globs (of size comparable to solder ball)of black things on each corner of the chip. I believe they are some kind of adhesives to keep the chip on place. I tried to scratch them out before reflowing but they were hard, so I couldn't. I thought they will just melt away when I do reflowing so moved on. But even after about 5 minutes of heating, I wasn't able to nudge (slight movement) the chip. Since a successful reflow requires that you nudge the chip (and it will come back to its place itself), I continued to heat and after sometime a cracking sound came. I could see that from the rim of the top shiny rectangle of the chip some shiny solder like metal was squeezed out. I stopped immediately and let the things cool. I tried to scrub off the squeezed out shiny metal and it came out clean. I did partial assembly and found that my motherboard was now completely dead.
I hope the story was interesting to you.

PS: no electrolytic caps were nearby. And no component on the mother board looks damaged.

[DerStrom8]

Re: Laptop Dead except for the lights and fans.

Well, I did remove all removable parts, including CPU. I did use aluminum foil to protect other parts. I practiced reflowing in a scrap desktop mother board before trying on this one.
There were like three small globs (of size comparable to solder ball)of black things on each corner of the chip. I believe they are some kind of adhesives to keep the chip on place. I tried to scratch them out before reflowing but they were hard, so I couldn't. I thought they will just melt away when I do reflowing so moved on. But even after about 5 minutes of heating, I wasn't able to nudge (slight movement) the chip. Since a successful reflow requires that you nudge the chip (and it will come back to its place itself), I continued to heat and after sometime a cracking sound came. I could see that from the rim of the top shiny rectangle of the chip some shiny solder like metal was squeezed out. I stopped immediately and let the things cool. I tried to scrub off the squeezed out shiny metal and it came out clean. I did partial assembly and found that my motherboard was now completely dead.
I hope the story was interesting to you.

PS: no electrolytic caps were nearby. And no component on the mother board looks damaged.

I'm not so sure about the part in bold above. Nudging the chip will do little but cross the solder beads underneath and create shorts. You'll probably need to put vertical pressure straight down on the chip, but horizontal movement must be avoided.

How exactly did you heat up your board? Did you put it in an oven, or did you use a heat gun?

You did not mention the cracking sound before. That could mean the hair-thin wires within the chip are now broken, and your only chance would be to replace the chip, or the entire mobo.

Matt

[gabik111]

Re: Laptop Dead except for the lights and fans.

Well, I did remove all removable parts, including CPU. I did use aluminum foil to protect other parts. I practiced reflowing in a scrap desktop mother board before trying on this one.
There were like three small globs (of size comparable to solder ball)of black things on each corner of the chip. I believe they are some kind of adhesives to keep the chip on place. I tried to scratch them out before reflowing but they were hard, so I couldn't. I thought they will just melt away when I do reflowing so moved on. But even after about 5 minutes of heating, I wasn't able to nudge (slight movement) the chip. Since a successful reflow requires that you nudge the chip (and it will come back to its place itself), I continued to heat and after sometime a cracking sound came. I could see that from the rim of the top shiny rectangle of the chip some shiny solder like metal was squeezed out. I stopped immediately and let the things cool. I tried to scrub off the squeezed out shiny metal and it came out clean. I did partial assembly and found that my motherboard was now completely dead.
I hope the story was interesting to you.

PS: no electrolytic caps were nearby. And no component on the mother board looks damaged.

Looks like you overheated GPU and the core of GPU separated from rest of it. Only you can do is replace chip.
Normally when I'm doing reflowing I'm using machine with special hot air exhaust tip and thermocouple that measuring temperature (thin hair that you can slide underneath chip). Depends on board thickness , solder ball used (leaded or not) and chip itself the temerature is diferrent up to 230C (with RoHS compliant solder balls) but temperature at the exhaust tip can reach even 400C. Reflowing is not easy process and if you do not want to damage your board you should use preheater installed on bottom of you board to avoid deformations and heat stress of the motherboard. Reflowing lead-free solder balls is much difficult and needs more heat .