[pcductape] Corroding contact fingers, Right way to clean.

  • From: "Bob Noble" <bnoble@xxxxxxxxx>
  • To: <pcductape@xxxxxxxxxxxxx>
  • Date: Sun, 19 Dec 2004 10:00:17 -0800

Contact fingers is one of the things I worked on at HP. Like why do they not make contact. Sorry about the carbon, not so. It happens mostly because there is very little gold on the contacts. Gold is expensive. You have to plate enough of it to close most of the holes in the plating, but that takes a lot of gold, so they just barely plate enough to close most of them. Closing all of them is almost impossible anyway.
What happens is moisture in the air helps make a small battery out of the different metals and it produces by products that are like crystals that actually form an eruption at a hole site. As it erupts from corrosion, it lefts the fingers. This is similar to what happens when you see rust. Rust is the eruption stuff. But it's iron so it looks brown. The contact salts are green to blue, mostly, if you can see them. You need a good microscope to see most of them. Now when the crystalline salts are wet, they are conductive, but when they dry, they are insulators, so bad connection.
This is one of the reasons your computer might not work at home, but when you put it in your car and take it down a bumpy road to the shop, it vibrates and may clear. When you get to the shop, it all works fine, until you take it home and the process continues and eventually, the same problem, again.
We determined that an eraser should not be used as it just also removes more gold so you can make the problem even worse in time.
The right way to clean them is with a combination of about seventy five percent alcohol to twenty five percent clean water. A lint free cloth is used. Just water or just alcohol will work ok too.
This is also why you will see grease like substance on phone contacts and other contacts. Grease will work fine for this, as long as contacts don't open and close like in a relay. If they open and close, the grease stuff will burn when it makes or breaks contact and then, Sandi, the carbon stuff will form. The grease stuff forms a barrier to moisture and air, two things you also need to cause corrosion. Oil in the grease is what forms the barrier. So, one could also use a small bit of oil also.

More then you wanted to know. :O)
Bob Noble
----- Original Message ----- From: "Huntress" <sanneumann@xxxxxxxxxxx>
To: <pcductape@xxxxxxxxxxxxx>
Sent: Sunday, December 19, 2004 7:59 AM
Subject: [pcductape] Re: STOP error (moved to Freelists)

He's saying that he has had this happen on a few Dells recently and the problem was with the RAM contacts becoming dirty so you have to take them out and clean them with a pencil eraser and put them back in. The "dirt" is actually carbon deposits that can be caused by voltage fluctuations. :-)

----- Original Message ----- From: trapper
To: pcductape@xxxxxxxxxxxxx
Sent: Saturday, December 18, 2004 11:41 PM
Subject: [pcductape] Re: STOP error (moved to Freelists)

Are you saying that a re-seating of his memory is all that is needed??

David Emery wrote:
I have run into a few Dells lately that I have had to remove and clean the memory with an eraser and reseat them, caused all kinds of problems from no boot to erratic problems. Sorry I didn't see your post earlier. Dave
At 02:19 AM 12/18/2004 -0600, you wrote:

     Hi De,

     I cannot boot to bios.
     I cannot boot to A drive.
     I cannot boot to my CD drive.
     I cannot boot to my DVD drive.

I was able to run Dell's dynastic (I used Ctrl+Alt+D keys) and both drives are ok. I still cannot boot to bios nor any drives, although I do see the light come on when I turn the computer back on; that is the A drive lights up and the CD drive lights up (the DVD drive does not light up), yet the system will not stop on A nor CD drives. It will only go to the blue screen with the error message.

I no longer have possession of the machine; it's in my friend's computer repair shop.


----- Original Message ----- From: DGrell7446@xxxxxxx
To: pcductape@xxxxxxxxxxxxx
Sent: Friday, December 17, 2004 7:58 PM
Subject: [pcductape] Re: STOP error (moved to Freelists)

In a message dated 12/17/04 1:49:56 PM Central Standard Time, ctm007@xxxxxxxxxxxxxx writes:

I'm thinking the same thing. I'm thinking the registry is corrupt and maybe non exist. Maybe a virus or Trojan delete my registry. A good lesson in all this is to make a copy of the registry and put it on a cd for safe keeping. But, my issue is, I cannot get to an A nor CD prompt.
My crash was caused by an inproper shutdown.
Check your bios setup for the first boot device and set it to what you would like.
When I totally wiped the drive (I could not get the repair program to run) and reinstalled I had to boot from the 4 floppy disks that I made from the Win2000 make a disk directory and then it directed setup to the CD and it installed Win2000.
If you have not made these disks and need a NTFS boot disk (to read your hard drive so you know that it is ok) go to NTFS.com (hope that is the correct address) and get one. That is where I got one and was able to read my hard drive. Alot to the disk that I was not sure of, it is a neat disk tho.

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