Laptop not reaching POST

[Gwalchgwyn]

Anyone fancy a guess at what might be wrong with this laptop?

After pushing power button, HDD light flickers on, then off again. Fan whirrs up and sometimes CD tray makes noise. Screen is completely blank - no backlight. Shuts down again after about 10 seconds and tries to reboot. Does this indefinitely.

Battery light flicks off and on metronomically when charger cable is in

Has booted up normally twice after having the battery removed and the power button held for 30 seconds, but doesn't anymore.

Won't boot up at all without battery in place

If i leave power cable plugged in overnight, the battery light stays on - it doesn't flicker.



Thinking either a battery, motherboard or processor problem. Any way to check without swapping parts out? Don't have any spares :/ I've completely dismantled it, cleaned everything and rebuilt it - nothing was noticeably wrong aside from an abundance of dust. Tried swapping the fan for another in case it was an overheating problem but nothing.
Any ideas?

Oh its an Advent Roma 1000 if that means anything.

 

[DocGreen]

Anyone fancy a guess at what might be wrong with this laptop?

After pushing power button, HDD light flickers on, then off again. Fan whirrs up and sometimes CD tray makes noise. Screen is completely blank - no backlight. Shuts down again after about 10 seconds and tries to reboot. Does this indefinitely.

Battery light flicks off and on metronomically when charger cable is in

Has booted up normally twice after having the battery removed and the power button held for 30 seconds, but doesn't anymore.

Won't boot up at all without battery in place

If i leave power cable plugged in overnight, the battery light stays on - it doesn't flicker.



Thinking either a battery, motherboard or processor problem. Any way to check without swapping parts out? Don't have any spares :/ I've completely dismantled it, cleaned everything and rebuilt it - nothing was noticeably wrong aside from an abundance of dust. Tried swapping the fan for another in case it was an overheating problem but nothing.
Any ideas?

Oh its an Advent Roma 1000 if that means anything.

Remove everything... HDD, DVD, MiniPCI(s), Unplug any USB cards attached to the board, and if you have a stick of good ram, remove the old and put just one stick of known good ram. Try powering it on then, see if you can get it to post. If not, you're pretty much guaranteed it's a board-level problem.

Judging by the issues you mentioned with the battery, I would check the charging circuit first.

 

[Gwalchgwyn]

Hi, i've stripped the laptop down to bench and also my laptop that i know works. I've tried the dodgy laptops monitor on mine and it produces the same fault. However, i tried booting my laptop without RAM and it produces the exact same fault (no RAM failure beeps) - keeps trying to boot indefinitely. I've tested both sticks of RAM in the dodgy laptop in both ports separately and together and nothing changed.

I'm fairly confident its a power supply problem but worried it could be also be a motherboard failure or even a problem with the monitor or its power inverter. I don't have spares of these parts to test so this looks pretty dire :/

 

[JustInspired]

...Oh its an Advent Roma 1000 if that means anything.

Yes, it means it's a total piece of rubbish. We've seen a lot here and they are (including pretty much any Advent) crap.

Anyway, we have one that comes in every few months or so with similar issues. We remove the cmos battery for a few minutes, replace it and it starts working properly again. It's like a ritual now.

Have you tried removing it?

 

[Gwalchgwyn]

Yeah i['ve removed the cmos battery but only for 10-20 seconds or so.

 

[Gwalchgwyn]

Just one last opinion before i go ahead and buy parts for replacement.

I've stripped it down to bench, and tried a known working screen in the laptop, but produced the same fault. Funnily enough though, if i tried its screen on a working system, that system produced the same fault. I don't know whats going on there but that concerns me a bit.

I bought a new working battery for that laptop but that did nothing as suspected. I've tried removing the CMOS battery for an extended period of time (24 hours) as suggested but that did nothing different.

I'm pretty sure its a defective motherboard. Two working batteries have been used in the laptop with the same effect. Two working screens tested and brought the same effect. I haven't been able to test the RAM properly as i don't have known working spares but i tried each stick in each port separately. It produces the same fault when run on bench through mains without a battery. The battery light does turn on when the mains lead is plugged in, so the wire to the mobo isn't defective.

It feels like the motherboard isn't moving power around correctly or something has happened to its ROM and/or BIOS, as nothing comes on screen, not even a backlight when powered on.

Reckon a new motherboard will do the trick? I'm only asking because i really can't afford to spend £50 on a motherboard, find that that isn't the problem, and tell my customer i can't repair it and charge them nothing.