Its friday 13th and my Daughters PC has given up. I thought it was the HDD but I've swapped one I know is good but nothing works. You switch it on, all the fans work, and you get a couple of clicks from either HDD (old & replacement) but nothing on the screen. Removed the gameing card and plugged the monitor into the standard socket but still zilch. My theory was either a power fault or main CPU. I have looked it up and its an AMD Athlon 64 x 2 4200 2.2ghz. I would expect the heatsink to at least be warm after a few minutes even being the large chunk of ally & a fan cooling it - but its stone cold. Any ideas? I'm drawn to CPU failure but would like more of an expert opinion. Daughter has gone out & purchased a new PC and if I can repair this one at a reasonable cost, it will be a great improvement on the antique i'm currently using.
Any ideas would be appreciated.
Thanks
Robin the Technician (cars & Trucks, that is)
|
|
Does it make any beeps? My money is power supply, +5v has gone
|
Thanks for the very quick response!!
No bleeps - just sits there humming away to itself. I've seen a video on Youtube on how to test the power supply using a fan - I can try that unless you can suggest another test method. Was suspecting that but as the CPU, case and video card fans all came on as soon as it was strated up, i wasn't sure...... any further suggestions.
Thanks
Robin the Technician
|
I assume you are handy with a multimeter, check out the web for the voltage pin outs from the power supply on the motherboard.
www.helpwithpcs.com/courses/power-supply-basics-inc-pinouts.htm
The lack of beeps are, in likely order of probability
1/ power supply
2/ CPU (tho some BIOS's may beep an error code)
3/ Memory (again some BIOS's may beep an error code)
|
Beep codes:
www.bioscentral.com/
But, as suggested, seems like a PSU that's given up the ghost.
|
Hi everyone,
First of all, thanks to those who replied - your advice was very helpful.
I just thought you would like some feedback on how the probelm was fixed. I did suspect the power supply but still had doubts as all the fans were working. So, I had a spare older power supply which was pre SATA but I fitted it in and as the HDD had both SATA and older style sockets I plugged it in. It worked!!! The power supply was indeed not working. As the older power supply was a lower wattage and would not cope with the high spec graphics card, I resigned myself to buying a new one.
However, not being defeatist, I decided to have a look inside the PSU to see if anything was obvious I could fix. Lo and behold, I found a capacitor that had dry solder joints and the blue wire that looked like it had never been soldered, just jammed into the hole. These were re-soldered and the unit reassembled. Re-fitted it back into the PC and it worked fine!!!
Job sorted!!!
Just goes to show you that just because something has failed doesn't mean it can't be fixed. Initially the PC was destined for the bin!!! The job cost nothing to repair although my Daughter has been relieved of a few quid for a spanking new PC.
Again thanks for the helpful advice.
Robin the Technician
|
A computer supply has separate rails with different voltages. It is very common for one rail to fail (e.g the 12v) so some fans will still spin but nothing else.
The switch connected to the motherboard is directly connected to the switch circuit on the power supply, so even if the board is dead it will still switch the power supply on.
Also a word of warning, with power supplies the wattage isn't that important, it is the ampage on the 12v rail you need to be concerned with. As you will know the wattage is just a figure of how much energy it can consume, where as the ampage is the figure of how much power it can actually deliver.
Car alternators are never rated in wattage for that exact reason, but computer hardware manufactures like to mislead people hence the obsession they have with wattage.
Last edited by: RattleandSmoke on Mon 16 May 11 at 13:23
|
|
Rats, to deliver more DC amps, it needs to consume more watts. Its a direct comparison and is valid. You are getting a little mixed up with efficiency, and load. A good power supply should be 90% efficient at 50% total load.
Last edited by: Zero on Mon 16 May 11 at 13:32
|
Yes but say a 500w you need to know more importantly how many watts if delivered for each rail. Some of the cheaper power supplies have low rating on the 12v which make them not suitable for power modern PCs.
There is also the efficiency argument, some of the cheap and nasty power supplies consume a lot of watts because they are just very inefficient. I can show you many 500w power supplies with very different amp/rail ratings.
I personally just stick with FSP and Corsair unless the customer exists they just want a cheap and temporary repair I will use a cheap one then.
By comparing both the ampage and wattage figure you get a good idea how efficient the power supply is.
Last edited by: RattleandSmoke on Mon 16 May 11 at 13:34
|
|
The figures given for each of the DC power outputs is the Max that rail can produce without power being drawn from any other rail, when the other rails are drawn upon all the rails must go down, thats is why the total wattage/efficiency is the important number, not the ampage per rail.
|
IIRC ohm's law states......Watts = volts x amps.
Irrespective, if you want 500w you can only put in so much amperage according to the volts!!!
It does not matter anyway as I fixed the original one as supplied with the PC. The lower Watt substitute was used with the graphics card removed as it draws quite a bit of power. The test worked to check if the PC booted... which it did. By process of elimination (by whatever means) I indentified the problem and had resigned myself to buying a replacement PSU. However, being one not to like spending money 'just because its broken, buy a new one' I decided to open the PSU up. It was 2 dry joints on a capacitor and a non solder on a blue wire. a qiuck re-solder and it worked!! Job fixed at zero cost!!
Result.
Robin the Technician
|
Fine for home use, I used to do that sort of thing myself when I was still handy with a soldering iron. For my job though its not worth the risk in case it burnt a hose down.
I am the same I hate spending money on my PC, my hard drive is full of bad sectors and I know it needs replacing but I can't justify spending the £40 on a new drive but tomorrow I will bit the bullet and replace it. I do back up though.
I will buy a new 1TB one I think.
I tend not to recommend reflows on laptops because it costs too much and it is often only a temporary repair. Reballing is another matter but it is so expensive it is not worth it.
If any of my cars ECUs brake though I would certainly attempt to repair it, I cannot believe dealers charge upto £1000 for a new one when in many cases it is a popped capacitor in the ECU which simply needs replacing.
|
>> I can't justify spending the £40 on a new drive
You would if you had important files likes photos or videos on it. I know you say you have a backup. Call my paranoid (had a drive fail and did nearly lose some files) but:
- Mac uses Time Machine to backup all the time so I can go back to old versions of files
- I sync my important folders to a NAS and that also holds video files etc too - this is mirrored
- I often sync the NAS to an external 2Gb hard drive - a file system error could still wipe out data
Currently processing some photos into a slideshow (MP4) from my holiday last week...
|
I don't have that many important files really, but if I lose them they might become important.
Not formatted for two and a half years so it will be nice to start a fresh. I really need a new PSU, new motherboard etc as my motherboard is getting close to five years old now. I will just buy a new drive when I am next at Microdirect and replace the rest another time.
The sector reallocation count is very high on mine which is why I know it should be replaced.
And while I have an internet back up of all my business files if my backup drive failed as well I would loose all my personal stuff.
Really need a new motherboard, as mine only takes upto 2GB of RAM and I want to be able to make better use of virtual machines. The problem is a new motherboard means a new processor, new windows licence etc.
Did you have a good holiday?
Last edited by: RattleandSmoke on Tue 17 May 11 at 19:17
|
>> Did you have a good holiday?
Tuscany was very nice thanks. Stayed a few km from San Gimignano.
|
Acer Aspire M1100 - Zero
