problem about high milage computers

S

SuperFudd

Senior Member
Hi all,

Here is a problem that may kill some high milage computers.

I am still fighting a problem with this 7 year old computer. My friend and fellow former employee of MDS, Gary, worked on it again today. I am 99.9% certain we finally found the problem this time. The voltages from the power supply connects to the main board with a plug. So much 5V electricity is used that 5 wires are used to carry it all. They should have used 6, or a better quality plug.
Because of the high current, a little heat is developed at the 5 plug contacts, much like a plug on a vacuum cleaner or electric skillet will get warm during use. With the excess warmth over 7 years of heavy use, the contacts corroded causing a poorer still connection and a voltage drop at the contacts. Intermittently the voltage drops too low and the computer shuts down. I tried cleaning the contacts which helped but I should try it again.
See system below:
 
The heat will also make the wire insulation brittle possibly causing a voltage leak from the cables. this will compound your power issue.
By the way good to here all is not lost with the comp.
 
Much more likely that you have cheap nickel plated connectors which will corrode over the years. This is why professional equipment uses gold plated connectors which cost considerably more. This has always been a problem with computers built on the cheap, since the early days of Commodore Pets and Tandy TRS80s.

It is very unlikely that you have sufficient heat generated due to connector voltage drop to do any damage.

Your options are to periodically clean the connectors (and all of them will at this sort of age be starting to give problems) with a mild abrasive, or to replace them, preferably with gold plated ones. A very good abrasive for this is believe it or not a banknote, but you will find you have to do this operation more and more often as time goes on.

Dave Bird
 
Common problem on early motherboards along with capacitors giving up the ghost, they have improved drastically these days though.
If you or your friend are up to it soldering wise the connectors can be replaced as can the wires from the PSU to the plug or just drop in a replacement PSU.

However may be worth checking any electrolytic capacitors for signs of leakage, bulging or dry joints as they can have an effect on voltage. Early Symptoms would be a reluctance for the PC to boot up taking a couple of resets before it kicks into life or as you seem to have random shutdowns and reboots, fairly easy to replace on older boards.
Also worth checking are any additional voltage regulators on the motherboard they do generate heat and can suffer from dry joints, resoldering or replacing them usually cures any problem.

The hardening of the wire would probably have a resistive effect and slightly drop the voltage but it shouldn't cause any fluctuations.
 
bird_d00 said:
Much more likely that you have cheap nickel plated connectors which will corrode over the years. This is why professional equipment uses gold plated connectors which cost considerably more. This has always been a problem with computers built on the cheap, since the early days of Commodore Pets and Tandy TRS80s.

It is very unlikely that you have sufficient heat generated due to connector voltage drop to do any damage.

Your options are to periodically clean the connectors (and all of them will at this sort of age be starting to give problems) with a mild abrasive, or to replace them, preferably with gold plated ones. A very good abrasive for this is believe it or not a banknote, but you will find you have to do this operation more and more often as time goes on.

Dave Bird
Click to expand...

Gold plated connectors have their own problems, insert memory with gold plated connectors into a conventional motherboard and the motherboard goes within three to six months. We had that problem on IBM computers using IBM components.

Cheerio John
 
bird_d00,

Could you send me one of those British bank notes? a 1K note should do.;)

Cleaning the connector is quite difficult. both the pins and the sockets are reccesed in thier plastic shells. I supose if I had the tool I could remove the socket (female) connected to the wire from it's shell and replace it. Yes I could replace the ~20 pin male connector on the MB but, even with proper equipment, I would probably make a mess of it.
I used small pieces of 600 grit water proof sand paper and a very small jewlers screw driver in my attempt to clean them.
 
Superfudd,

The idea of using a bank note is that it is a very mild abrasive, using sandpaper on a regular basis and you will quickly destroy the thin nickel layer and be down to the copper. A fibreglass scratch brush is also effective (and a damned sight easier to use) but also too abrasive to be used on a regular basis.

John,
Yes cheap gold connectors can give problems when connected to non-gold mating parts. It is generally because someone has still purchased the cheapest connector they can get hold of, and the gold is only 2 - 3 molecules thick. You can then get gold migration under the effect of electric charges.

I'm afraid you get what you pay for. To make a connector properly you need nickel barriers over the copper and then a decent thickness of gold on the top. This does not come cheap, and you won't get this sort of quality
in a high street PC store.

Dave Bird
 
Could you send me one of those British bank notes? a 1K note should do.;)
Click to expand...

Sorry no more £1 notes.....

The only denominations produced are £5, £10, £20, £50 - but the size varies with the denomination (unlike the US - all the same size). The larger notes will be too big for your purpose - however, I'm quite happy to exchange £5 for $10 (US)

Colin
 
Excuse me for interjecting gentlemen, but I have been using a product called WD40 to repair electrical devices for ages. Everything from sticky relay contacts to auto/truck/trailer connectors. Any good reasons why it would not work in this situation?

tomurban
 
A new PSU would sound like your best bet. You can find a relatively cheap one over at newegg that is 500W and is like 70 bucks? And is of decent quality(a little louder since it isn't high end) but when playing trainz you hardly notice it when the sound is cranked up. It is very simple to install a PSU and takes about 10 minutes.... It can be one of several small upgrades that can breath new life into an old machine... I am running on a 7-8 year old machine myself....
 
The computer was working fine all day yesterday. Voltages were very stable.
When I went to bed I ran a full Symatec scan. 4 hours later I got up to see how it was doing. The screen was black. I wiggled the mouse but no response. I pressed the reset button. After boot up I checked and that scan had reported nothing. Ran the monitors for voltage and multipliers and all was well, then the pointer went away. I wiggled the wires at the MB connector and could hear clicks. Probably the hard drives, but no pointer.
Reset button. more of the same. I hate turning the power off with Windows up but that is what I did and went back to bed.
When I finally got up I was greeted by the Blue Screen of Death. ;<
"UNMOUNTABLE_BOOT_VOLUME". Yes, XP was hosed. Could not even get to safe mode. I double checked the BIOS and then set it to default. Still BSD.
So I could have XP repaired or replaced but, judging from the clicking when I wiggled the wires, that connector is worse than I thought, or perhaps plugging and unplugging it has cracked a trace as the board flexed some.
No point fixing XP. It will just get hosed again. I could try replacing the MB connector and the power supply first, but I would probably screw the connector change up. I may just remove the hard drives and DVD burner to put them in this 500MHz machine and bury the rest.:'(

Don
 
I am unsure how many bays your computer has for HDs, but what you can try an do is get another HD and format it to windows XP, then boot from that HD to see if it is in fact the connection(or if it is just the OS itself) OR possibly even the motherboard has given out, although highly unlikely. What to do is get another HD(roughly the same size as your current HD) then format that to windows. Then boot it(if it boots fine then we know its the OS installation and not the connection) Then all you would need to do is either A install the other HD into a open slot(if the old computer even has one) or B you can buy a external enclosure for the HD to temporarily place it in to access the files on it and copy them over to the new HD.
Changing the Mobo connector and power supply would only benefit the system further(although as I cannot see the system myself it is hard to say) Perhaps you could post some pictures so us tech nerds can see in more detail...
Best of luck,
Gandalf-Mike
 
The problem is the power supply conector to the main board. Either the MB conector or the one on the power supply wires, or both, are not of high enough quality so that after only 7 years, the 3 contacts for the +5V made a poor conection droping the 5V too low for the MB to work reliably. I supose the best fix would be to cut at least one of the 5V wires loose from the ~20 pin conector and solder it to the underside of the MB at a +5V pin of the board's conector, bypasing the conector's contacts. Then I could tackle the corupted Windows problem.
You can't have an itermitantly crashing computer often requiring shuting the power off without first shuting down windows without the likelyhood of OS coruption.
 
Hi SuperFudd,

I have seen numerous posts from you in which you have expressed your satisfaction with the performance of Trainz on your aging config. I have taken particular note of your views on this, as its a sentiment for which I have quite some sympathy (while I am lucky enough to be in the position to update my Trainz PC every couple of years or so, I always buy at near the bottom of the current technology curve - by my reckoning over time this gives me better back for buck than buying half as often at the bleeding edge).

Anyway, where I am leading with this..

Maybe its time to bury the old war horse!. Given that (with realistic expectations) quite satisfactory Trainz perfomance can be had from a machine now a few years old, and given your current expectations set by a 7 yr old setup, if you look around you should be able to pick a quite acceptable replacement at quite a low cost (for example, maybe an aging business ex-lease machine you can throw your current graphics card and HD in). Might save you a lot of angsting, at a reasonably low price, and keep you going for a few more years yet.

Just a thought !

Phil
 
Thanks for the tip Phil. Hmmm...

You think the 7 year old computer is slow? This is a 10 year old computer, 500MHz P3, GForce2 mx400, 2 10G HDs. I am running TRS2004 on it. It will have to do until I can manage a new/nearly new machine. I was about to get a new one a year ago but then got my 3 month warning layoff notice. I am still between jobs so things are still on hold.:confused:
 
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