Questions about reseating RAM

[RegEdit]

What is it about reseating the RAM chips that causes a computer to become fixed and boot again?

I had a customer bring in a desktop that would display just a black screen when turned on. No blinking cursor. No ability to enter the BIOS. The fans were running.

I put a new CMOS battery in. Problem fixed.

Then 2 months later. Same problem. CMOS was fine. I reseated the battery after blowing compressed air. Still won't boot. So next I cleaned and reseated the RAM. Then it boots up fine. So that was the solution, but I want to know why. Was dust getting in there? How the hell does this happen?

[morr]

Most likely "Chip Creep", something the clips should in theory prevent...... but don't entirely eliminate

[RegEdit]

Chip creep IS creepy! Hope they don't have chip creep on the space shuttle.

[Rob]

Originally Posted by RegEdit

What is it about reseating the RAM chips that causes a computer to become fixed and boot again?
So next I cleaned and reseated the RAM. Then it boots up fine. So that was the solution, but I want to know why. Was dust getting in there? How the hell does this happen?

This is an extremely common problem where I live, we generally clean 2 or 3 a week. We're on the coast, it's salty and humid. The contacts on the RAM & occasionally in the mb socket get a thin corrosive layer on them. Reseating the RAM generally scratches through this layer and the computer can once again detect the modules, and boot as normal. We use a contact cleaner & occasionally a pencil eraser before reseating them, and then load up the case with moisture absorbent sachets.

[RegEdit]

This is an extremely common problem where I live, we generally clean 2 or 3 a week. We're on the coast, it's salty and humid. The contacts on the RAM & occasionally in the mb socket get a thin corrosive layer on them. Reseating the RAM generally scratches through this layer and the computer can once again detect the modules, and boot as normal. We use a contact cleaner & occasionally a pencil eraser before reseating them, and then load up the case with moisture absorbent sachets.

I always thought that if metal is contacting metal then you're good, but I guess what you're saying is that corrosion can work its was IN BETWEEN metal on metal contact. Makes sense.

What do you use the pencil eraser on? Just the RAM chips?

How many moisture absorbent sachets do you put in there, where do you put them and how do you attach them?

Great ideas by the way!

[Rob]

The pencil eraser gets used on the contacts too. We don't use it as much any more as the contact cleaner is pretty effective.

The sachet tip is one we learnt from a local trawler fisherman who literally filled up a sock(!) with them and left it in the bottom of the tower that lived on his boat. We normally put 1 or 2 loose in the bottom, they're non-conductive so they won't short anything - we tell the owner not to lie the tower down when taking it home so they keep out of the fans.

[RegEdit]

What contact cleaner do you use?

[Rob]

It's an aerosol spray that we get from Dick Smith (sort of like Best Buy). It's a nondescript generic can, no brand that I can remember sorry. I've also experimented with WD-40, and it has been effective too. Probably a very similar product.

[RegEdit]

I use Xtreme Klean air duster spray. I think it's just compressed air.

Regarding this product that you use, do you have to wipe it off or do you just spray.

[Rob]

Wiped off with a lint free cloth.