Computer totally freezing after a few min

Try Memtest86 and/or Memtest86+ (competing products (free) that once shared a common code base) for some additional insight. Each can be run from a boot floppy or CD.

Could be.

Yes, probably, but you'll have to be the judge as to whether your experience and tools are adequate.

Thanks for your reply.

MemTest86 came back clean. I dont think it is the RAM as I took out all sticks but one, had the same problem, then swapped out the one reaming stick for another one and still had the problem. So unless all the RAM was damaged (an MemTest said no) then it isnt the RAM.

I'm going to look through my spare parts to try to find a PS and RAM just to

If I find another CPU with the same type of socket can I swap that in (ie if it fits will it work on the MB?). Also, if the caps are bad would this damage the CPU or just make the CPU voltage unstable (If I find a CPU that fist will I damage it by trying it on a MB with bad caps)?

Thanks again

as

if

Specific CPU requirements (core voltage) aren't always compatible on all motherboards; modern ones are better.

The 'few minutes' symptom appearance suggests heatsink issues; have you checked all the thermal pads/heatsink goo connections between chips and heatsinks? A temperature-watchdog circuit would freeze the system AND disable most reset functions. A voltage-watchdog would be more likely to shutdown or reset (neither of which is seen).

Instead of using a different CPU, consider (depending on what the BIOS allows) underclocking the one you have.

Specific CPU requirements (core voltage) aren't always compatible on all motherboards; modern ones are better.

The 'few minutes' symptom appearance suggests heatsink issues; have you checked all the thermal pads/heatsink goo connections between chips and heatsinks? A temperature-watchdog circuit would freeze the system AND disable most reset functions. A voltage-watchdog would be more likely to shutdown or reset (neither of which is seen).

Instead of using a different CPU, consider (depending on what the BIOS allows) underclocking the one you have.

I have not check the heatsink compound on the CPU. I didn't want to pry it up until I was sure this was the route I wanted to take. A few years ago when I built he computer I used Arctic Silver heat sink compound and a whoopy-do high tech fan.

Ho can I tell if any of the other CPUs will be compatible (I don't have any specs on them and would be just transplanting them from another old system)?

I would hate to under clock as a permanent solution. I would consider upgrading the MB and processor, but I have a feeling that if I'm not careful will run into a BSOD with a different drive controller on new MB. Might also have problems with Widows activation as there will be such a radical change to hardware.

Thanks

Ray Inscribed thus:

What you are describing is almost certainly "bad caps" It sounds like its a K6 M/B ! At that age the caps can be bad without showing any physical signs. Just replace the lot ! Thats all I do. Use good quality 105C caps. If you can't get the exact value in the correct case size use the next higher value. ie 2200 @6v use 2500 @6v.

Thanks. I'm headed in that direction.

ny

m)?

To determine compatibility, you need to squint and make out the part numbers on the logic board, and on the CPU chip. Do a search on that string, you will likely find all the manuals online, and the voltage ranges and setting details are all in there. Somewhere.

You might be pleasantly surprised at how little difference underclocking makes... even more pleasantly surprised if it DOES fix the problem. If this is a Socket 7 motherboard, a new CPU or motherboard or even RAM is not really possible; none of the current hardware is plug-compatible.

When stupid "designers" in Redmond, Washington produce broken-by-design pseudo-Usenet-clients it serves to screw up Usenet.

In turn, those who use those crappy products make it difficult to read the Usenet posts that they make. Some of those users know to hand-format their posts in a standard format and they do that.

...then there are people like you who don't hand-format AND don't apply ALL the patches available for their crap software:

I agree on capacitors as I replace very many, and some not all that old. I bought lots from Digikey but for motherboards I had a little better luck with Mouser and Nichicon. You do need a really good soldering iron to not damage the 4 (or more) layer boards and don't forget to clean off the flux residue.

G=B2

snipped-for-privacy@yahoo.com Inscribed thus:

I second your comments about Nichcon. I also use Panasonic and Rubycon ! A really good soldering iron and a preheat plate will help. The ground planes will really suck the heat out of an inadequate iron.

To determine compatibility, you need to squint and make out the part numbers on the logic board, and on the CPU chip. Do a search on that string, you will likely find all the manuals online, and the voltage ranges and setting details are all in there. Somewhere.

You might be pleasantly surprised at how little difference underclocking makes... even more pleasantly surprised if it DOES fix the problem. If this is a Socket 7 motherboard, a new CPU or motherboard or even RAM is not really possible; none of the current hardware is plug-compatible.

I'm going to try underclocking it and see if it helps the problem. It is a socket 478. I have the original manual with specs. What particular specs am I looking for to match with a new CPU?

I agree on capacitors as I replace very many, and some not all that old. I bought lots from Digikey but for motherboards I had a little better luck with Mouser and Nichicon. You do need a really good soldering iron to not damage the 4 (or more) layer boards and don't forget to clean off the flux residue.

G²

I haven't pulled the board yet to look. Do you think the cap connection will go all the way through and be accessible from the bottom of the board? Do you recommend using a desoldering pump, desolder braid, or just heating and pulling the old cap out. Then to clean the hole to insert the new part what is the best practice?

Don't worry about desoldering. Just pull the old caps. Then use a small drill to clean out the holes. I use a dremel drill with a micro-chuck. Place the new cap, then solder with plenty of heat to wick the fresh solder fully into the joint.

That is a great way to destroy the plated through holes.

True.

The big capacitors that failed are probably in plated-through holes, meaning that there are two wires that go into a hole in the board, which is soldered along its full length, with a little blob (fillet) of solder on the non-component side. As M.T. indicated, the solder joint COULD pull internal board layers apart if you just 'pull' the old caps.

So, you have to crush the capacitors, removing the bulky component except for those soldered wires. Then, clean, flux, and gently remove one wire at a time. It sometimes requires two soldering irons to get this kind of joint up to temperature, one on each side of the board; removing the capacitor body gives you the extra access to do that.

Solder braid may remove enough solder to loosen the wire, but if it doesn't come loose, ADD fresh solder to the joint; the old solder may have dissolved copper and taken on a high melting point, the fresh solder will get it back to normal loose-when-hot consistency. When the wires are out, use braid or a vacuum desoldering tool to open the hole fully (more flux might help). When all the capacitors are out, and all the holes clear, stuff the new components in, solder, and clean up the flux.

True.

The big capacitors that failed are probably in plated-through holes, meaning that there are two wires that go into a hole in the board, which is soldered along its full length, with a little blob (fillet) of solder on the non-component side. As M.T. indicated, the solder joint COULD pull internal board layers apart if you just 'pull' the old caps.

At least 50 caps replaced on PC boards with Zero problems. It's easy. Obviously the drill diam. is less than the original lead diam. I've been hand soldering electronics 40 years.

It's also easy to damage a board. A better solution is to heat up the pad an poke a cold resistor lead, or some such, through the hole. This will clear the solder without damaging the barrel.

That just means you may have a lot of experience doing things wrong. ;-)

bw Inscribed thus:

If you do it properly the hole will be cleaned by the vacuum pump.

Fastest way to destroy a plated through hole !

Yes, or pull a clean length of stripped 26 gauge copper wire through it.