Cleaning contacts

I have a Dell Latitude C540. I was a sick hand me down from my son.
1. The CDRW sometimes does not work. It's a plug-in device. When I
jiggle it it come to life.
2. Have two memory slots. At random I get a blue screen. The only way I
can recover is to remove and reinstall the memory stick from slot #2.
It's not the memory stick because it did it also when I swapped them.
Got it to work by arranging down pressure on stick number #2.

Suspect that in both cases contacts may need cleaning. The slots are
very narrow so it is impossible to reach in. Could I give it a shot of
WD40? I used it before for this purpose but not on computers.

Any suggestions?
Thank you for your help,
Nathan

Hello:

Back when I was still working, we cleaned contacts with a rubber eraser. I
would not use any spray cleaner because you have so little control over
where it all goes.
Jim
"Nathan" wrote in message
...
I have a Dell Latitude C540. I was a sick hand me down from my son.
1. The CDRW sometimes does not work. It's a plug-in device. When I jiggle
it it come to life.
2. Have two memory slots. At random I get a blue screen. The only way I
can recover is to remove and reinstall the memory stick from slot #2. It's
not the memory stick because it did it also when I swapped them.
Got it to work by arranging down pressure on stick number #2.

Suspect that in both cases contacts may need cleaning. The slots are very
narrow so it is impossible to reach in. Could I give it a shot of WD40? I
used it before for this purpose but not on computers.

Any suggestions?
Thank you for your help,
Nathan

Hello:

Back when I was still working, we cleaned contacts with a rubber eraser. I
would not use any spray cleaner because you have so little control over
where it all goes.
Jim
"Nathan" wrote in message
...
I have a Dell Latitude C540. I was a sick hand me down from my son.
1. The CDRW sometimes does not work. It's a plug-in device. When I jiggle
it it come to life.
2. Have two memory slots. At random I get a blue screen. The only way I
can recover is to remove and reinstall the memory stick from slot #2. It's
not the memory stick because it did it also when I swapped them.
Got it to work by arranging down pressure on stick number #2.

Suspect that in both cases contacts may need cleaning. The slots are very
narrow so it is impossible to reach in. Could I give it a shot of WD40? I
used it before for this purpose but not on computers.

Any suggestions?
Thank you for your help,
Nathan

I don't think WD40 wouldn't be good for electrical contacts, since I think
its an insulator. Using rubbing alcohol may work, and/or Radio Shack may
still sell a spray contact cleaner.

Jim wrote:
Hello:

Back when I was still working, we cleaned contacts with a rubber eraser.
I
would not use any spray cleaner because you have so little control over
where it all goes.
Jim
"Nathan" wrote in message
...
I have a Dell Latitude C540. I was a sick hand me down from my son.
1. The CDRW sometimes does not work. It's a plug-in device. When I jiggle
it it come to life.
2. Have two memory slots. At random I get a blue screen. The only way I
can recover is to remove and reinstall the memory stick from slot #2.
It's
not the memory stick because it did it also when I swapped them.
Got it to work by arranging down pressure on stick number #2.

Suspect that in both cases contacts may need cleaning. The slots are very
narrow so it is impossible to reach in. Could I give it a shot of WD40? I
used it before for this purpose but not on computers.

Any suggestions?
Thank you for your help,
Nathan

I don't think WD40 wouldn't be good for electrical contacts, since I think
its an insulator. Using rubbing alcohol may work, and/or Radio Shack may
still sell a spray contact cleaner.

Jim wrote:
Hello:

Back when I was still working, we cleaned contacts with a rubber eraser.
I
would not use any spray cleaner because you have so little control over
where it all goes.
Jim
"Nathan" wrote in message
...
I have a Dell Latitude C540. I was a sick hand me down from my son.
1. The CDRW sometimes does not work. It's a plug-in device. When I jiggle
it it come to life.
2. Have two memory slots. At random I get a blue screen. The only way I
can recover is to remove and reinstall the memory stick from slot #2.
It's
not the memory stick because it did it also when I swapped them.
Got it to work by arranging down pressure on stick number #2.

Suspect that in both cases contacts may need cleaning. The slots are very
narrow so it is impossible to reach in. Could I give it a shot of WD40? I
used it before for this purpose but not on computers.

Any suggestions?
Thank you for your help,
Nathan

Addended: I have to agree with Jim that if you use the spray contact
cleaner, it's sometimes a challenge to limit where it goes, although some
have a small straw-like tube to guide it.

Bill in Co. wrote:
I don't think WD40 wouldn't be good for electrical contacts, since I think
its an insulator. Using rubbing alcohol may work, and/or Radio Shack may
still sell a spray contact cleaner.

Jim wrote:
Hello:

Back when I was still working, we cleaned contacts with a rubber eraser.
I would not use any spray cleaner because you have so little control over
where it all goes.
Jim
"Nathan" wrote in message
...
I have a Dell Latitude C540. I was a sick hand me down from my son.
1. The CDRW sometimes does not work. It's a plug-in device. When I
jiggle
it it come to life.
2. Have two memory slots. At random I get a blue screen. The only way I
can recover is to remove and reinstall the memory stick from slot #2.
It's
not the memory stick because it did it also when I swapped them.
Got it to work by arranging down pressure on stick number #2.

Suspect that in both cases contacts may need cleaning. The slots are
very
narrow so it is impossible to reach in. Could I give it a shot of WD40?
I
used it before for this purpose but not on computers.

Any suggestions?
Thank you for your help,
Nathan

Addended: I have to agree with Jim that if you use the spray contact
cleaner, it's sometimes a challenge to limit where it goes, although some
have a small straw-like tube to guide it.

Bill in Co. wrote:
I don't think WD40 wouldn't be good for electrical contacts, since I think
its an insulator. Using rubbing alcohol may work, and/or Radio Shack may
still sell a spray contact cleaner.

Jim wrote:
Hello:

Back when I was still working, we cleaned contacts with a rubber eraser.
I would not use any spray cleaner because you have so little control over
where it all goes.
Jim
"Nathan" wrote in message
...
I have a Dell Latitude C540. I was a sick hand me down from my son.
1. The CDRW sometimes does not work. It's a plug-in device. When I
jiggle
it it come to life.
2. Have two memory slots. At random I get a blue screen. The only way I
can recover is to remove and reinstall the memory stick from slot #2.
It's
not the memory stick because it did it also when I swapped them.
Got it to work by arranging down pressure on stick number #2.

Suspect that in both cases contacts may need cleaning. The slots are
very
narrow so it is impossible to reach in. Could I give it a shot of WD40?
I
used it before for this purpose but not on computers.

Any suggestions?
Thank you for your help,
Nathan

Nathan wrote:
I have a Dell Latitude C540. I was a sick hand me down from my son.
1. The CDRW sometimes does not work. It's a plug-in device. When I
jiggle it it come to life.
2. Have two memory slots. At random I get a blue screen. The only way I
can recover is to remove and reinstall the memory stick from slot #2.
It's not the memory stick because it did it also when I swapped them.
Got it to work by arranging down pressure on stick number #2.

Suspect that in both cases contacts may need cleaning. The slots are
very narrow so it is impossible to reach in. Could I give it a shot of
WD40? I used it before for this purpose but not on computers.

Any suggestions?
Thank you for your help,
Nathan

What I've been taught, is the following two tidbits.

1) Tin on tin contacts. Tin is a metal which forms an oxide on the outside
fairly rapidly. When you plug two tin items together, the contact force
wipes the contacts against one another. This scrapes the oxide off, and
fresh metal makes contact with metal. Where the metal meets, you have
metal biting into metal. That forms a gas tight bond. Any metal still
exposed to the air, will have oxide forming on it again.

2) Gold on gold contact. This works on a different principle. Gold
on gold has lower friction, so it takes less effort to insert
one into the other. Gold is a precious metal, and doesn't oxidize.
Gold works best, by just coming in contact with the other gold surface.

Now, what happens if we use an abrasive. This is my interpretation.

1) An abrasive could remove foreign matter on a tin surface. But as for
the metal itself, an oxide would form soon after on the metal. So cleaning
the tin itself, seems to me to be pointless. It is designed to clean itself,
using the friction of insertion.

2) An abrasive used on the gold contact, could remove foreign matter. Due to
the reduced friction in the gold case, it might be harder for the contact
force to remove foreign material. "Polishing" the gold shouldn't be needed,
because the gold doesn't oxidize. The gold is a plated layer, and is very
thin. Good quality products use 50 microns, while cheap computer components
may use 10 microns or less. Using an eraser on such items, runs the risk
of burning right through the gold, to the less noble metal underneath.
And then it is downhill from there.

From those two examples, it would appear that using a solvent on the contacts,
to remove foreign matter, is about as much cleaning as you should do. For example,
on a PCB production line, sometimes solder resin falls onto contact surfaces.
Alcohol is known to dissolve the hard resin material. So rather than use an
abrasive and try and scrape all the stuff off, the solvent is used instead.
Some PCB systems, actually wash the PCB with alcohol after soldering is completed.
(They used to use trichloroethylene [Trike], but that is a suspected carcinogen.)
This may remove the majority of the foreign matter, but the drying solvent
leaves behind a thin coating of resin or other byproducts.

If you must clean, then wiping the DIMM contacts with alcohol might be
a reasonable cleaning process. Grinding off the plating, less so.

In addition to contact cleaners (which may contain alcohol or fluorocarbon
agents), there are also "contact enhancers". It is unclear to me at least,
whether in the long run, something like that would be a solution or not.
Virtually any fluid you might apply to electronics, could attract dust.
Like, for example, the residue from the WD40 is going to gather dust.
Which is only going to mean there is more dirt waiting to get into the
contact area.

Summary:

1) If there is visible foreign matter on the contacts, clean it off
with a solvent. Try to use several applications, to dilute any
residue. Allow to dry thoroughly before reassembly (so no dust
or dirt is picked up). Remember to take antistatic precautions
when handling the items.

2) While using compressed air, to remove dust, may seem like a fine
idea, that can generate static electricity. The static is generated,
when the dust particles bump into stuff. An example where you would
not use that, is a PCI Express video card slot, as some of those
seem to be rather sensitive to static.

3) If you need to apply abrasion, simply insert the item into the
connector five times in a row. The insertion and removal gives you
natural abrasion from the contact wiping action. Connectors have a
finite life, and five insertions is intended not to use up all the
contact life. That may be sufficient to wipe off small amounts of
foreign matter. For example, when I had a new motherboard with an
Ethernet connector, and my network connection didn't work, five
insertions of the connector fixed it.

4) If the slot on the board is fouled (you spilled Coca Cola in the slot),
then you're going to need plenty of solvents, selected to not damage
the electronics. Alcohols are a good candidate, as isopropyl won't
hurt anything. But not all foreign matter is soluble in alcohol.
And stronger cleaning agents may do more damage than good. In this
case, you're on your own :-)

There are companies that specialize in chemicals for electronics.
Even though they're pros, I wouldn't use half of the stuff
advertised on the site. I'm not a fan of "lubricants" because
they are a "residue". I want something which is an effective
solvent, which leaves as little of itself behind as possible.
(You'll notice isopropyl made it to the chart here.)

http://www.mgchemicals.com/downloads...pguide0104.pdf

http://www.hmcelectronics.com/cgi-bi...ronics-ES7300/

So you can imagine what I think of WD40 :-)

HTH,
Paul

Nathan wrote:
I have a Dell Latitude C540. I was a sick hand me down from my son.
1. The CDRW sometimes does not work. It's a plug-in device. When I
jiggle it it come to life.
2. Have two memory slots. At random I get a blue screen. The only way I
can recover is to remove and reinstall the memory stick from slot #2.
It's not the memory stick because it did it also when I swapped them.
Got it to work by arranging down pressure on stick number #2.

Suspect that in both cases contacts may need cleaning. The slots are
very narrow so it is impossible to reach in. Could I give it a shot of
WD40? I used it before for this purpose but not on computers.

Any suggestions?
Thank you for your help,
Nathan

What I've been taught, is the following two tidbits.

1) Tin on tin contacts. Tin is a metal which forms an oxide on the outside
fairly rapidly. When you plug two tin items together, the contact force
wipes the contacts against one another. This scrapes the oxide off, and
fresh metal makes contact with metal. Where the metal meets, you have
metal biting into metal. That forms a gas tight bond. Any metal still
exposed to the air, will have oxide forming on it again.

2) Gold on gold contact. This works on a different principle. Gold
on gold has lower friction, so it takes less effort to insert
one into the other. Gold is a precious metal, and doesn't oxidize.
Gold works best, by just coming in contact with the other gold surface.

Now, what happens if we use an abrasive. This is my interpretation.

1) An abrasive could remove foreign matter on a tin surface. But as for
the metal itself, an oxide would form soon after on the metal. So cleaning
the tin itself, seems to me to be pointless. It is designed to clean itself,
using the friction of insertion.

2) An abrasive used on the gold contact, could remove foreign matter. Due to
the reduced friction in the gold case, it might be harder for the contact
force to remove foreign material. "Polishing" the gold shouldn't be needed,
because the gold doesn't oxidize. The gold is a plated layer, and is very
thin. Good quality products use 50 microns, while cheap computer components
may use 10 microns or less. Using an eraser on such items, runs the risk
of burning right through the gold, to the less noble metal underneath.
And then it is downhill from there.

From those two examples, it would appear that using a solvent on the contacts,
to remove foreign matter, is about as much cleaning as you should do. For example,
on a PCB production line, sometimes solder resin falls onto contact surfaces.
Alcohol is known to dissolve the hard resin material. So rather than use an
abrasive and try and scrape all the stuff off, the solvent is used instead.
Some PCB systems, actually wash the PCB with alcohol after soldering is completed.
(They used to use trichloroethylene [Trike], but that is a suspected carcinogen.)
This may remove the majority of the foreign matter, but the drying solvent
leaves behind a thin coating of resin or other byproducts.

If you must clean, then wiping the DIMM contacts with alcohol might be
a reasonable cleaning process. Grinding off the plating, less so.

In addition to contact cleaners (which may contain alcohol or fluorocarbon
agents), there are also "contact enhancers". It is unclear to me at least,
whether in the long run, something like that would be a solution or not.
Virtually any fluid you might apply to electronics, could attract dust.
Like, for example, the residue from the WD40 is going to gather dust.
Which is only going to mean there is more dirt waiting to get into the
contact area.

Summary:

1) If there is visible foreign matter on the contacts, clean it off
with a solvent. Try to use several applications, to dilute any
residue. Allow to dry thoroughly before reassembly (so no dust
or dirt is picked up). Remember to take antistatic precautions
when handling the items.

2) While using compressed air, to remove dust, may seem like a fine
idea, that can generate static electricity. The static is generated,
when the dust particles bump into stuff. An example where you would
not use that, is a PCI Express video card slot, as some of those
seem to be rather sensitive to static.

3) If you need to apply abrasion, simply insert the item into the
connector five times in a row. The insertion and removal gives you
natural abrasion from the contact wiping action. Connectors have a
finite life, and five insertions is intended not to use up all the
contact life. That may be sufficient to wipe off small amounts of
foreign matter. For example, when I had a new motherboard with an
Ethernet connector, and my network connection didn't work, five
insertions of the connector fixed it.

4) If the slot on the board is fouled (you spilled Coca Cola in the slot),
then you're going to need plenty of solvents, selected to not damage
the electronics. Alcohols are a good candidate, as isopropyl won't
hurt anything. But not all foreign matter is soluble in alcohol.
And stronger cleaning agents may do more damage than good. In this
case, you're on your own :-)

There are companies that specialize in chemicals for electronics.
Even though they're pros, I wouldn't use half of the stuff
advertised on the site. I'm not a fan of "lubricants" because
they are a "residue". I want something which is an effective
solvent, which leaves as little of itself behind as possible.
(You'll notice isopropyl made it to the chart here.)

http://www.mgchemicals.com/downloads...pguide0104.pdf

http://www.hmcelectronics.com/cgi-bi...ronics-ES7300/

So you can imagine what I think of WD40 :-)

HTH,
Paul