More RAM Problems

[Zacko10000]

Heres the problem:
I had a 486 and was installing more RAM. Once installed I attempted to boot up the system but it failed and gave off a beep code. I identified this code to be some error with the RAM. I took out the newly installed RAM, it still wouldn't boot up, so I took out the original RAM, messed around with that for an hour or two, trying different RAM slots, different chips, etc. It still doesn't work. For reference I took all the RAM and tested it in another computer, it worked! There is no other problem with the computer. Power supply, physical condition of motherboard, graphics adapter, all check out. What is wrong with the computer. Could the RAM slots be damaged in some way? Is there any easy way to fix them, or to check to see if they are?

Also, on another note, I have been trying to equip some of the computers in my collection of 486s with more then 16MB RAM. I install more but it doesn't detect it in the RAM counter when I start up the machine. I know I installed the RAM correctly and that it was the same type (in some cases exactly the same in every way). I take out the original RAM and replace it with different RAM chips it will still work. All the RAM works, why won't the computer acknowledge it? What is going on here?

[BBA]

486 machines and some Pentiums did not have bios code to recognize over certain amounts of ram (I believe it was when 1M cost about $40, no one saw this as a shortcoming).

Most ram probems with early boards can be corrected by flashing the bios, some do not have that capability.

On the one that wont boot, clear the cmos memory by removing the battery for a while or by resetting the ccmos jumper/switch then try again.

BBA

[Zacko10000]

ok, thanks. I never had to do this so here's my question, where is the CMOS battery, is it just a small watch battery or do I need to remove an IC Chip.

[philipg]

The battery looks like a little cylinder about an inch long its usually in the back next to the keyboard connector you may have to de-solder one terminal or you can pull the chip but I wouldn't recommend it unless you can't solder very well to clear the cmos. If you have the watch battery type just lift the clip for a couple of seconds and all should be fine. After you clear the memory you should get a 'cmos checksum error' Enter the bios load bios defaults and save on exit. This may get you going or like BBA said.