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#241783 - 17/11/2004 17:15 Laptop hardware troubleshooting...
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
I've got a Dell 600m that has gone tits up, and I've exhaused everything I can think of.

A month or so ago, the power swtich started having issues where you'd have to press it just right to get it to turn on. I didn't think too much of it, figuring I'd replace the switch when it finally went. Fast foreward a few weeks, and the computer starts refusing to turn on. Now, every once in a while it'll turn on a boot and work for at most 5 minutes before shutting off. Once it's shut off, it'll only manage to blink the LEDs before turning itself back off. No about of unplugging or resetting will fix this. It can die anytime in the startup process, weather the bios has finished loading or windows has finished loading, it doesn't care. At one point the bios gave an error about shutting the computer down because it had been too hot, but it hasn't given that error since the first day it really died.

The odd thing is that the power switch itself is fine. I swapped it out, figuring it would help with debugging, but a new one works just the same, and the old one on the other laptop works fine.

So at this point I can only conclude that the power supply is dead. Of course, seeing as the power supply is on the motherboard, there doesn't seem like there's much I can do besides replace it. Rumor has it that will cost %650, and seeing as new 600m's cost $750, I'll probably replace-and-harvest if I go down that route, but I really would prefer not to.

Is there anything I can do to fix the power suplly myself?

Matthew

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#241784 - 17/11/2004 17:22 Re: Laptop hardware troubleshooting... [Re: matthew_k]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14486
Loc: Canada
Unplug the battery (remove it) and see if that makes a difference or not.

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#241785 - 17/11/2004 17:26 Re: Laptop hardware troubleshooting... [Re: mlord]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
Done that. I've got two batteries and two AC adapters, I think I've tried virtually all combinations. The problem cropped up shortly after starting to use my seccond battery for the first time in a few months, though I suspect that's just coincidence.

Matthew

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#241786 - 17/11/2004 21:45 Re: Laptop hardware troubleshooting... [Re: matthew_k]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
I think Mark was suggesting not having the battery inserted at all while the computer boots. Have you tried that? (Sorry if that's what you already understood, but my first parsing of his suggestion was to simply remove the battery and plug it back in.)
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#241787 - 18/11/2004 07:15 Re: Laptop hardware troubleshooting... [Re: matthew_k]
Shonky
pooh-bah

Registered: 12/01/2002
Posts: 2009
Loc: Brisbane, Australia
Ooh! ooh! me! me!

I had a Dell Inspiron 8000 that was doing something very similar. Symptoms were it would power on, CD drive would reset laser motor, HDD would spin. Then a few seconds later - power off.

Sometimes it would work fine, sometimes it wouldn't work at all. Sometimes it would just turn off the display it seemed. Pressing the power button made it hibernate normally though.

Turns out the problem was a reed switch inside main section near the touchpad. There was a magnet in the LCD/lid that the laptop used to detect when the lid closed. The reed switch had broken, and the two metal fingers inside were contacting sometimes which made the laptop think the lid was shut - so it turned itself off.

I was pulling it to bits in a car while being driven to a customer's factory in Korea when I discovered it I think. One thing that seemed to fix it sometimes was flexing the case a bit. It flexed a fair bit actually.

Very different laptop of course, but it's definitely worth a shot. It's a fair bit of pulling apart though. First stop would be pulling out the keyboard (K screws on the back). The then P ones for the touch pad.
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Christian
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)

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#241788 - 18/11/2004 18:13 Re: Laptop hardware troubleshooting... [Re: wfaulk]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
Yup, Tried it without batteries of any sort. Sorry for not making that clear.

Matthew

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#241789 - 18/11/2004 18:16 Re: Laptop hardware troubleshooting... [Re: Shonky]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
Hmmm. Interesting. I think i've found the display switch, and I'm fairly certain it's on the circuit board with the power/volume buttons that I swapped with a known good. I'll check it out again though.

My only thought left is to disassemble it to the point that I can see the power supply circutry, which looked to involve removing the entire processor cooling system.

If only apple would release a nice shiny new powerbook I'd be in a lot less of a rush to fix this thing.

Matthew

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#241790 - 19/11/2004 00:00 Re: Laptop hardware troubleshooting... [Re: matthew_k]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
Well, I took it apart again, taking the fan/heatpipe assembly off and didn't manage to find anything. Did pull out a ball of lint about the size of an almond, which was probably the source of the death of whatever component has died.

Everything looks as good as can be, no easily identifiable burn marks or anything. Still the same symptoms of almost starting up when it's been left off for a long time, then refusing to do anything but blink the lights when you press the power button after that. Sometimes it blinks them for longer than others, but the more often you do it, the shorter they stay on.

Does this sound like a capacitor or some other component that's dieing as soon as it heats up? Is there any way to diagnose which one it might be?

The only thing left that I could swap out is the processor, which I may try tomorrow. Is there any chance it could be the processor itself?

I'm open to any advice... (Though I think I'm off to find a stiff drink at the moment, so there's no need to reccomend that)

Matthew

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#241791 - 19/11/2004 01:10 Re: Laptop hardware troubleshooting... [Re: matthew_k]
mlord
carpal tunnel

Registered: 29/08/2000
Posts: 14486
Loc: Canada
I doubt the processor. I'd expect it to either keep working same as from the factory, or to stop completely. Not work for a while and then stop.

Mmm... solder joint?

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#241792 - 19/11/2004 21:00 Re: Laptop hardware troubleshooting... [Re: mlord]
matthew_k
pooh-bah

Registered: 12/02/2002
Posts: 2298
Loc: Berkeley, California
Quote:
Mmm... solder joint?

Sounds likely to me. Not sure what to do about that. Perhaps I'll get out the magnifying glass the next time I disassemble it.

Matthew

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#241793 - 19/11/2004 21:45 Re: Laptop hardware troubleshooting... [Re: matthew_k]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
Post it to me and I'll fix it for you. Gizzajob, I can do that...
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One of the few remaining Mk1 owners... #00015

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#241794 - 19/11/2004 23:47 Re: Laptop hardware troubleshooting... [Re: schofiel]
gbeer
carpal tunnel

Registered: 17/12/2000
Posts: 2665
Loc: Manteca, California
I seen it where the power socket has seen so much strain that the solder holding it to the motherboard fatigued and cracked loose.

I've always wondered if there were internal planes in the board that connect to that socket's leads. It would be a pain to reconnect those.
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Glenn

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