Questions

PC is Dead????

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PC is Dead????

Judasin
Hello there,

I recently was asked by my kids teacher to repair her computer. Generally I am very good at these things, I spent a lot of time in school and learning by breaking and fixing my own computers for years. Just so you understand that I have already gone thru the standard trouble shooting procedures. Here goes.

This computer did not power up at all. The MoBo light did come on but otherwise the system was dead. None of the fans came on, power LEDS didnt light, nothing. I have seen this before and immediately decided that the MoBo was dead and replaced it (I can get parts at a very reasonable rate), I also replaced the Power supply as its just good practice. Again, I got the light on the MoBo but again got nothing else.

Perturbed, I pulled all the parts. Down to the Front USB cables and checked each one in a system that I have especially set up for this type of parts checking. Every part worked like a champ including the processor. The only thing I couldn't test was the CPU fan, but I tried to boot without it connected and still got zero response from anything but the MoBo light. I even replaced the case, as I thought perhaps the the front panel pwr switch was faulty. Nothing.

So now I have a system with a new case, Mobo, PwrSupply, cables, everything and its no more along than it was. I am very distressed by this and would very much appreciate any helpful responses.
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HAL 9000 Moderator

Is to run the system out of a case without anything connected except the bare minimum attached. You can short out the front Power Pins to get the system to start.

Also test the RAM as while it may work on one M'Board it may not be compatible with another M'Board.

Col

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mjd420nova

I"ve serviced a large number of units that had compatablity issues that stopped it dead. One of the biggest was the memory, and the other was the bad routing and mounting of interface cables for the drives. If plugged in backwards, they will give you the same indications. Use a magnifier to check the pin one locations for all drives. I have seen a few mfgrs that will swap the connector orientation to clean up the insides and shorten cables.

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karmashock

Look up the mobo, cpu, ram, vidcard (if it has one), etc and see if it all is to spec.


if it is and I assume the initial stuff had to be because I assume it worked at some point.

Then you have effectively four to five things to worry about. PSU, MoBo, CPU, Ram, and vid card (if it has one) in that order.


The best way to test is to have compatible spares of the above. Then it's just a process of elimination.


You pick up little tricks over time that let you "guess" what it is by things like sound, the type of blinking, etc.

I would personally download the manual for whatever Mobo you're trying to boot. The mobo is the smartest thing at bootup... yes... pretty dumb but it generally knows what's going on. I stick to Mobo's that will tell you specifically what's wrong when they boot. Abit is especially good about that.


Also consider what your time is worth here... I know it might be a **** to your pride to let this go... but it sounds like you've already wasted more time then this is worth. Unless it was a nice computer I'd junk it and get a new one.

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Jesus_C

tested the cmos battery?

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nahoda_i

MB with installed processor connected to power (and speaker for MB w/o internal speaker) out of case. Any other cables, memory, peripherals etc. Then after shorting power pins system must start and you can hear some "beeps". If not MB is broken. Is very rare found bad processor.
If worked try to add memory a switch on. Beeping must changed - beeping pattern is describing missing part - see manual or internet, but this is vendor depend. Next try is add gpaphics card etc. That's the way to isolate problem.
Hope help you.

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kpak44wh

Truth is, if you do this for a friend or for a job, you have
spent alot of time on this project( time is money, and your
skills are worth money). If all else fails, it would probably
be cheaper to buy a barebones system, and put all her
stuff
back on it. It probably be cheaper for her, and she would
get a faster system out of it too. I saw one for $120 at
tigerdirect. I charge $50 an hour when I work on a
system, so
I have to balance that with the customer and what they
want.
you have to know when it's time to stop, and try
something else. That's the part alot of techs have
problems with, including me sometimes.

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Judasin

Well I have to first thank everyone who replied, your answers for the most part were very helpful. Heres the follow up.....

I again stripped everything. I have another system that is compat. with all the parts in the dead one. I have checked every part 10 times including the Procc and RAM. Everything in the dead one works in the testing until I put it back in the dead system, then nothing. No beeps, no fan spin, no nothing!

Now I must be honest here (maybe it will help) I have been doing this for 8 years, fixing PC's, Networks, etc. I am generally considered very good at what I do (I even do phone support for friends in other countries with great success) Ive never had a sys. I couldnt fix. That said this sys has totally blown me away.

So im going to give it one more go and if it doesnt work out, I'm gonna smash it with a hammer :-0 Not really, I'll work out something else and keep trying to fix this piece of cr** until time ends......

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oznbolivia

Judasin Good morning.

Have you removed the dead MB and installed all parts and tryed to run it out of the case? Maybe something is shorting out the MB to the case. Is there anything shorting the parts side of the MB, hairpin something spilled into the case. Did you swap the keyboard? A stuck key will lockup a computer. What is displayed on the screen?

Oz

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HomusOnline

Totally agree with this. A couple other less than obvious reasons to get a NP/NV like this:

Are any of the connectors on the back loose or have broken solder joints? Very possible a connection you are not using, but is used at the users home (like a USB port they connect a printer to) may be loose. When you put it back in the case, pressure from the back plate may be causing the short.

Also, the back plate itself. I've seen the flaring that surrounds the connectors on the back bend the wrong way and touch the board when put back in.

Also, scan the board and any case connections (button board, headphone jacks) for shorts, loose connections or corrosion. These can hide annoying little problems. And I am pretty sure we all have amazing stories of what a little coke or coffee can do to a system.

I would also be interested in hearing what this system does outside the case. Or what another group of parts would do if they were put in this case.

You sound experienced and proficient, so I figured I would go the direction of oddities and annoyances that have caused similar issues. These are the kind of systems that ruin a day (or weekend). Hope these help or lead you to the problem.

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Hillel

If the PC was just run of the mill, no special video card etc that might require older mother board connections, then why not move the data disks to another new machine and use it as a d: drive. Looks like you've pretty much got new everything else anyhow.

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Mayhem1969

in the old computer when you move the parts to the compatible computer is the problem. If it's the MB, then that is the defective part. Either you've scored two defective MBs or your getting a short on the new one when installed. Check to make sure the new MB is not touching the back of the case or something else that could cause a short.

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willcomp

Ensure that Clear CMOS jumper is in "normal" position.

Is 12VDC CPU auxiliary power (4 pin plug) connected?