Dead System

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My home system – p233/w95/off97 – is dead. I switch on the power and the monitor LED comes on but the box does absolutely nothing. No lights, no noise. I assumed initially that this was a dead power supply – broken somewhere after the feed to the monitor- and was all ready to switch it when I thought I remembered something about dead monitors causing the same symptoms. Can anyone confirm that?

Thanks

Brooke

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The first thing I would check is that the brightness and/or contrast control on the monitor has not gotten turned all the way down. Also check that the monitor cable has not come unplugged. Is the power cord to the processor box plugged in on both ends?

Do any lights on the processor box come on or flash?

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Is the power cable to your monitor plugged into the back of your PC – i.e. do you have one power switch on the front of the box that powers on both PC and Monitor?

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Legare,

I tried all the leads to make sure they were seated and twiddled all the knobs – no joy.

Leif,

Normally I run the monitor out of the back of the PC, but I’ve tried it from a separate source as well with the same results – no sound, movement or lights from the box and a blank screen, though the ‘power on’ LED on the monitor is on.

Thanks,

Brooke

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That does sound a bit terminal as far as the PSU is concerned, I’m afraid.
If you are getting a power feed to the monitor when it is connected to the back of the PC I think it is safe to assume there is power getting to the PC PSU. These, as a rule, are self contained units and internally fused. If a fuse has gone, it will have gone for a reason.
Unless you are competent at fixing PSU’s I would not recommend having a go yourself. If you insist on opening the PSU, be VERY careful – they tend to have capacitors that may be holding upward of 400V, depending on where the fault lies.
Unless this all turns out to be something silly and obvious, I suggest a quick trip to a local repair shop. I know of a few in Bucks if you need suggestions.
Otherwise, depending on your system, you may be able to buy a replacement and fit it yourself. If it is not a big name like Dell (who most likely make their own), I think they are industry standard sizes.

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Leif,

Don’t worry, no fried Brooke for tea tonight – I’d just swap the entire unit over – I’ve got several spare. I just don’t want to do that if it’s not the power supply. I was just curious because I vaguely remember hearing something about pc’s not booting if the monitor has gone and the pc doesn’t get a sensible signal back from it (presumably because you can’t see what you’re doing so wouldn’t want to go any further?) Unfortunately, whilst I’ve got PSU’s coming out of my ears, I’ve only got the one monitor, (unless i can somehow rig a feed to my laptop?) so i guess i’ll swap the PSU and see if that works.

I would be interested in your top ten list of computer corner shops, though.

Brooke

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Not heard of the No Monitor – No Startup scenario before, I’m afraid. I think there is software you can get to control another PC over a LAN (as opposed to a KVM switch) which just wouldn’t work …
Otherwise, it sounds like you know what you’re doing.
Touch wood, I’ve not yet needed a corner shop – just what I’ve heard thru’ the grapevine…

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I’m not sure I’d go as far as saying that I know what I’m doing, but I do know a few of the things not to do…

Thanks for the advice – I’ll try swapping the psu over and hopefully that’ll fix it.

Brooke

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PCs should boot without a monitor, they just revert EGA mode. I’ve experienced this with a setup where 3 PCs share a single monitor via a data switch. (Thay act as interfaces between a number of systems in our property and only get looked when the interfaces don’t work.)

I’d say your problem is likely to be in the system box itself. (Hope I’m not dense but is PSU=PC System Unit??)

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PSU = Power Supply Unit

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Should have realised, mind I just pull ’em apart, didn’t say I could put it back together.

Thanks.

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Are you saying you’re not going to nip round and fix it for me? I’ve tried two spare power supplies and i get exactly the same symptoms(i.e. none). I’ve now replaced the original, though I’m not 100% sure why, and rechecked all the leads. Nothing. Maybe it’s time for professional help… And no – I didn’t take any part of the system into the shower.

Brooke

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Is your ‘Power On’ switch an little dinky push-on-push-off type, or a mechanical switch?

If the former, it is what I’d call a ‘logic’ switch – it is most likely sending a low-power signal to the MB to toggle the previous state and from there controlling the PSU. Can you check the wiring from the front of the box – there is usually a lightweight cable & plug connecting to near the switch.

If the latter, this is likely to be switching the mains power itself. It is feasible that it is a multi-pole switch – i.e. it switches power to the monitor output socket and the PSU (separately but together, if you follow my drift). If one of the switch contacts has broken down, that’s your problem.

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I’ll have a look at that tonight. Wish me luck….

Brooke

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Good luck, disconnect from mains before playing, and don’t have nightmares.

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The strangest encounter i’ve had with hardware problems was a system that didn’t respond.. After HOURS of troubleshooting, I found the hard-drive to be the culprit. After I replaced the HD, it booted fine.. You might give that one a try! (It never occured to me, and I was shocked )

Drk.

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My life’s on that hard-drive! What’s the smilie for blind panic? I’m off home to see when I last took a backup.

Brooke

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I know there are data recovery experts out there, i’m sure they charge a pretty penny or two, but if the data’s critical..

Try tossing a junk hard-disk into the system, or take it out completely and turn it on… Then you’ll know for sure!

Drk.

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Actually, send me the air ticket and…

Good luck tonight/today, let’s know how it pans out. if it is HDD.

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Well, I tried three power supplies to no avail, had a look at the switch, still nothing, put it back together with the original power supply, checked it, same symptoms, and took the rest of the afternoon off.

Got back in an hour ago and pressed the power switch for the hell of it…. it powered up perfectly. I’ve done quite a few hard restarts since and it seems that about one in ten start-ups succeed. Once the box ‘catches’ everything seems fine, everything working perfectly.

It would seem that something is on the way out, but I guess I’ll just have to wait until it becomes terminal to find out what, though I’m going to replace the power switch anyway as i figure that’s not going to be too expensive and is the most likely culprit.

In the meantime my backups will become a little more frequent – the last one was only a fortnight ago as it happens but that is pure luck: the one previous to that was taken last year.

If I ever get to definately locate the problem I’ll let you know what it is/was but in the meantime thanks for all the advice.

Brooke

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I replaced the switch and everything worked fine til last saturday. Then absolutely nothing – not even power to the monitor. I replaced the power unit and everything seems fine – so far. I would guess that my problems were both going together.

Brooke

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If you have been in and out of the box a bit before these problems, have a VERY good look for a loose part which may be causing an intermittent short. I had two weeks of very stressful and ultimately embarrassing experience several years ago when I shorted out an MB with a lost screw, and the PS would start to fire up and sometimes shut itself down (due to the short), and sometimes not, but either way the MB wouldn’t run!

Imagine the feeling in the pit of my stomach when in desperation I pulled the MB and … CLINK! Lost screw reappears, reassemble it all, and she’s good to go.

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