View Full Version : OT; Blown motherboard, what to save?

09-23-2014, 11:13 AM
Turned on my main computer this morning and the CPU fan started running away with itself. Upon opening it up (had no idea what I might look for yet) it was easy to spot several caps with bulging/leaking tops. This is a 12 year old Dell so I'm not surprised and although I could replace the bad looking ones at this point I think that might futile.

Thus my question. What to save? I can afford to just toss everything, which would probably be the smart thing to do, but I was wondering if there are things that might still be worth saving. I have never bought a new computer as I have been able to swap out, from free ones that people have given me, the parts to keep one going. So What are the chances that maybe the video card, network card, drives (including the hard drive), ram, and also the power supply might still be okay?

I will add that the blown caps are located in a row right next to the CPU (7 of 9) and in a row next to one of the ram slots (2 of 5).

09-23-2014, 11:21 AM
I once repaired a motherboard with that problem. On a 12 year old machine, though, I wouldn't bother. For the same reasons, I wouldn't bother pulling any parts either. Separate network cards are a thing of the past, they're built onto the motherboard now... as are video chipsets. You can still get separate video cards with more oomph for 3D work and gaming, but the built in ones are excellent these days. Your memory will be 100% useless with any modern system.

I suppose you could try to find a replacement motherboard but for a 12 year old machine... again, I wouldn't bother.

Keep your hard drive in case you need to salvage any data, but you'll want a serial ATA drive (rather than IDE) in your new machine so no point in keeping your old HDD permanently. If you happen to have a nice DVD burner or something in your old system I guess keep that... unless you want to take the opportunity to add a Blu Ray drive.

09-23-2014, 11:25 AM
Hi Gene
The row of capacitors is for a switching power supply on the motherboard that is used to power the microprocessor. If you can find low ESR replacement
caps and your soldering skills are up to it, it might be worth fixing. The rest of the machine should be fine if you decide to just replace the motherboard.

09-23-2014, 11:34 AM
I tend to save the power supply and the CPU heatsink. The power supply can be used for many 12V or 5V applications in the shop. The heatsink has uses too, I'm sure. I can just never think of any. That's why I have several in a box. I also have a box of fans, now that I think of it. They get pressed into service now and then.


09-23-2014, 11:35 AM
The problem with replacing the motherboard on a machine that old is that you'll either end up with a used motherboard basically as old, or you'll spend more than the entire machine is worth on a NOS one (if you can find one, which you probably won't).

New machines can be had for so cheap, I don't know why anyone would put themselves through any effort or expense just to continue to use such an old rig. Sure "it works"... but nowhere near as well as anything modern.

EDIT: Just wanted to mention for those who may not have heard of it, that Moore's Law is still very much in effect. In 2002 transistor count in a typical commercial grade PC processor was around 80 million. In 2014, it's in the billions (1.5 to 4 billion). Not to mention all the architectural changes around it... machines these days are in a whole different universe.

09-23-2014, 11:36 AM
I tend to save the power supply and the CPU heatsink. The power supply can be used for many 12V or 5V applications in the shop. The heatsink has uses too, I'm sure. I can just never think of any. That's why I have several in a box. I also have a box of fans, now that I think of it. They get pressed into service now and then.


Yeah, good call on saving the power supply! I have an especially nice PC power supply that puts out enough current to run the DC motor on my little watchmakers lathe. Those supplies are always handy for something.

09-23-2014, 11:47 AM
Computers are so darn cheap (inexpensive) now to replace, you literally may be losing money after trying to assemble salvaged parts, especially if you value your time and frustration tolerance.

You might try turning the parts over to the local PC repair place for a few dollars off on a used system, but how those places even remain in business in this day and age boggles my mind.

09-23-2014, 12:02 PM
You don't say which model of Dell you have, but I've got all my machines free from work as fails (I do the decommissioning). Optiplex 745 and 755 machines are just starting to fail and need four capacitors replacing, which takes about half an hour. We're giving about 30 620's to charity at the moment as nobody wants to pay 25 for them.

I actually had to buy a PC recently. I needed something with a lot of raw CPU power for video editing. It was taking a 755 about three hours to render a 20 minute video in 1080p25. I bought a used Dell precision T5500 quad core Xeon for 180 and cut the time to about thirty minutes.

09-23-2014, 12:53 PM
CPU heatsinks are great for making LED lights, that's what I use them for :)

09-23-2014, 01:36 PM
Well so far the power supply voltages checks. This a Dell GX 280 and despite being fairly old it does use a SATA HD and it had a 1gig Nvidia video card and a separate network card that can work in a lot of more modern computers. I would like to be able to keep those and the DVD player/burner.

09-23-2014, 01:47 PM
I am surprised that it just failed all of a sudden. Us usually when caps go, things get flakey and you get random crashes. Are you sure those caps are the problem?

09-23-2014, 02:27 PM
I am surprised that it just failed all of a sudden. Us usually when caps go, things get flakey and you get random crashes. Are you sure those caps are the problem?

Actually I have been noticing a few minor issues. Never a crash. The computer has been hanging up a bit. These are much like machinery, or vehicles or anything that you use everyday that you get a feel for the way it works when everything is happening just fine. But the internet can have issues, sites can have issues, new software, hardware, whatever, so I kind of just really didn't pay much attention to it. One thing I have done is to go with the free Norton software that Xfinity/Comcast has to offer. One of the things it does is flash a little notice up about CPU over usage. The diagram shows a sharp spike with it trailing downwards and the notice disapears. Another thing was when I would try to do a speed test the results were also erratic and this computer connected to the same modem shows a much smoother result.

So I am going to assume that the problem was in progress and when the load was high upon a start up it just finally had enough. This is really no loss. The machine more than paid for itself and actually up until very recently was working flawlessly. Just trying to save as much as what makes sense too.

09-23-2014, 03:09 PM
OK, that is more characteristic of noise issues on the power supplies. Given the bulges in the caps, your diagnosis makes sense.

09-23-2014, 06:31 PM
If you decide to try and replace the mother board, windows will not boot up with the new hardware. There is tricks out there to erase the drivers for the CPU, so that when it boots up, it will find the new Motherboard and try to load the new drivers. I successfully did on one of my machines.
Also if you decide to just load a new copy of windows on a clean HD, you are going to have to register your copy with Microsoft. Normally your license is tied to your original motherboard and they will not let you transfer it. I just told the Bombay help desk that the motherboard was blown by lightning and that this was the only replacement I could find. They accepted this excuse and gave me the new registry code. worked like a charm.

good luck

J Tiers
09-23-2014, 07:45 PM
Normally your license is tied to your original motherboard and they will not let you transfer it.

This is true of supplied-with-computer windows. When the computer dies, the license dies. "Dies" may be interpreted to be the motherboard, but it should be OK to put in a new one... it is done relatively often. After all, the "computer" is more than the motherboard.

For sure you cannot switch it to a new machine.... even if it works, it is illegal.

It is NOT true of windows you buy separately. That is not tied to anything.

09-23-2014, 09:29 PM
My last desktop was an HP, running WinXP, and it kept having problems with long boot times and random crashes. Occasionally I heard sounds like a capacitor popping, and eventually the machine just wouldn't boot at all. When I opened it up, I saw a bunch of capacitors on the MoBo had popped, just as it sounded like. I haven't fully stripped it down yet, as I simply started using a series of laptops for everything, but I'll probably save the power supply and a few other components. I dismantled an old PSU and removed the main transformer and a few other components, but in general there's not much of real value except to a die-hard experimenter and parts hoarder like me. ;)

My present machine is a Dell Inspiron 15 laptop with Win8, and although I don't like the new appearance, and it won't run some of my software, I like the way it starts working from sleep almost instantly and even cold restarts are pretty quick. It also will usually run for about 4 hours on a charge, which is 2 or 3 times longer than my previous machines.

I bought a refurbished HP desktop with Win7 for about $80 but I haven't used it yet. I plan to make it a workstation for my PCB designs (which won't run on Win8), and my Win7 Toshiba laptop has become sluggish either because of 3 years of bloatware or because of an unidentified HDD problem that keeps popping up (and has been doing so for a couple of years). I got my new machine after a wire stripper fell onto the edge of the keyboard and caused a BSOD, which required about 3-4 hours of self-initiated disk repair while I chewed my fingers to the bone expecting stuff to be lost, but it recovered 100%.

09-24-2014, 01:43 AM
As far as the m/board itself, I don't think there's anything to save that would be useful in another computer. I might be tempted to save anything that looks zoomy just for the eye candy thing. If you have a use for a heatsink, that might be worth keeping.

Charles Spencer
09-24-2014, 07:34 AM
The sheet metal of the case is not too bad.

09-24-2014, 08:50 AM
The disk drive shells are made from a nice cast aluminum alloy of some kind. Would make good material for foundry work.

09-24-2014, 10:35 AM
I think I will just wait for a another test mule to show up. I usually have one here that I would use to check out unknowns. I have an old P3 carcass but it's to old. The hard drive, video card and network card are fairly new. They had come out of a operating computer so I wasn't afraid of them then. Now I want to make sure with a test on something that don't matter.

This was the most strange event I have ever seen. I had no idea that one of those fans could run that fast. And because of their location next to the bad caps I am going to assume both the CPU and ram are toast.

Thanks everyone,

09-24-2014, 12:25 PM
OT; Blown motherboard, what to save?

From a 12 year old Dell? Nothing!!

09-24-2014, 12:56 PM
I'd yank the magnets out of the hard drive. They are "rare earth" (neodymium iron boron) magnets and are quite strong. There are two or four magnets used in actuating the swingy arm that the write head is on. The magnets are attached to two brackets above and below a thin copper wire coil.

09-24-2014, 01:21 PM
From a 12 year old Dell? Nothing!!

If everything were 12 years old, the thing would have been gone a long time ago. But the Hard drive, video card, and network card, are less than 1 year old. Not that I paid anything for them, just hate to throw out some pieces that I still might be able to use.