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IIci 64MB memory upgrade issues. Do I have the wrong RAM?
Posted by: croissantking on 2024-02-07 08:13:11
In reality is this a serious problem to be concerned about? I’ve never read anyone on here getting hold of a machine with galvanic corrosion in its ram sockets… then again, I don’t know how common gold plated SIMMs were. Maybe a good idea to alert the seller of these parts.
Posted by: Guy Madison on 2024-02-07 08:18:24
The Slaton modules I installed the other day were tinned, so they probably figured this out.

Ages ago I designed a couple motherboards.. (80486 era, so it's been awhile), you pick this stuff up when you sell a few hundred thousand units.
Posted by: danny.gonzalez.0861@gmai on 2024-02-07 08:46:36
I am no expert on the subject but I do know that old Nintendo consoles used the Hard Gold option on Game PCB's for durability. I mean it makes sense, think about how many times we would insert and remove a game in a old NES for example. Not to mention the obligatory blow into the connector which I am sure would have promptly corroded a non Hard Gold surface finish. (Yummy! We all did it!)

Of course this does not apply to RAM that will spend most of its life connected and relatively untouched.

This is indeed a VERY interesting subject and now I must continue to read and learn! The site that Unknown_K sent was extremely informative. Thank you for sharing that!

You guys (and possibly Gals) are a great plethora of information!

In case anyone wants a bit more info on the game side:
www.retrorgb.com

Determining the Build Quality of a Game Cartridge - RetroRGB

Follow me on Twitter @db_electronics There are many important aspects to consider when assessing the quality of a reproduction or modern release game cartridge. Shell, label, beveled edge, chamfer, surface finish, etc... are all important things to consider. To the untrained eye all PCBs may at...
www.retrorgb.com www.retrorgb.com
Posted by: Guy Madison on 2024-02-07 08:59:58
I am no expert on the subject but I do know that old Nintendo consoles used the Hard Gold option on Game PCB's for durability. I mean it makes sense, think about how many times we would insert and remove a game in a old NES for example. Not to mention the obligatory blow into the connector which I am sure would have promptly corroded a non Hard Gold surface finish. (Yummy! We all did it!)

Of course this does not apply to RAM that will spend most of its life connected and relatively untouched.

This is indeed a VERY interesting subject and now I must continue to read and learn! The site that Unknown_K sent was extremely informative. Thank you for sharing that!

You guys (and possibly Gals) are a great plethora of information!

In case anyone wants a bit more info on the game side:
www.retrorgb.com

Determining the Build Quality of a Game Cartridge - RetroRGB

Follow me on Twitter @db_electronics There are many important aspects to consider when assessing the quality of a reproduction or modern release game cartridge. Shell, label, beveled edge, chamfer, surface finish, etc... are all important things to consider. To the untrained eye all PCBs may at...
www.retrorgb.com www.retrorgb.com
Actually, it does affect RAM. In fact, it affects all components, especially when a computer is turned on and turned off all the time.

The components and the board they are installed into warm up and cool down which causes expansion and contraction which is movement.

That’s why you have to reseat memory in a computer that’s over 5 years old even with gold contacts.

It’s pretty cool stuff. I own a boat in saltwater, and I have to deal with galvanic corrosion.
Posted by: danny.gonzalez.0861@gmai on 2024-02-07 09:09:00
The components and the board they are installed into warm up and cool down which causes expansion and contraction which is movement.

That’s why you have to reseat memory in a computer that’s over 5 years old even with gold contacts.
You are indeed correct! Never though of it that way.
Posted by: croissantking on 2024-11-20 08:28:06
Damn, one of my 16MB Memorymasters modules (the same as the ones pictured earlier in this thread) has gone bad. Tried it in two different SE/30s and a IIci. Applying a bit of pressure on the RAM module (flexing the PCB, essentially) while booting gets it to work, but as soon as I let go the machine freezes. It definitely is one of the modules and not a SIMM socket since as I say I’ve tried in different machines and moved the module around.

The chips on the PCB are not touching each other, so I guess that instead one of the chips has a cold solder joint. Problem is, they’re so close together that I can’t get a solder iron in there to reflow them.

I will reach out to memorymasters to see if they’ll honour the warranty although I got the modules in a trade so don’t have the purchase receipt.
Posted by: obsolete on 2024-11-20 09:51:58
The chips on the PCB are not touching each other, so I guess that instead one of the chips has a cold solder joint. Problem is, they’re so close together that I can’t get a solder iron in there to reflow them.

If you can't get a warranty replacement, some flux and hot air (or even the old toaster reflow oven) might do the trick.
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