Need a little help finding memory for our Toyokoki press brake

Our Toyokoki pressbrake has an intermittent problem booting up. Sometimes it won't boot up at all, sometimes it will, and sometimes it says it has a memory parity error. This has been a problem for over 10 years but just started getting worse. We've checked everything we can think of and the Mitsubishi/Toyokoki tech looked at it a couple times and couldn't find anything wrong. Anyway I thought I'd see if I could find another memory stick and swap it out, but I don't know much about older computer memory. Hopefully someone here can help identify it.

It's 16 MB DRAM, 72 pin. Not sure if it's FPM or EDO but from googling the part numbers on the chip I think it's FPM 60ns. I'm also not sure if it's parity or non parity but I suspect it's parity because I got a parity error a few times at boot up.

Any help would be appreciated!

60ns(nano seconds) is pretty quick for memory of that vintage.
The parity error could be a bad memory check at boot up.
Use a soft pencil eraser across the contacts.
Thermal expansion is a slot problem with this family.
Not all memory is marked parity. Best way to tell is to bring up
the "Set Up" screen at boot. On older computers key F2... Very early in the boot.
Once in Set Up the type of memory is identified as well as processor, bus speed, cache-if any, ect.
For that memory the processor is likely to be a 486. Something like a Intel 486 Dx-2 90.
Might be a Pentium 1 but doubtful.

How many memory slots are in the board?
Is there documentation about the control board? ie: processor upgrade-able? maximum memory?

I have memory and processors that go back to nearly the dawn of time.
Check your messages as I will send one with my email.
Regards, John

Looked thru some boxes and there is a number of 72 pin memory.
There are some pairs of 8MB so if there are two slots that will give
you 16 MB.
If there are two slots move the 16MB memory to the vacant slot.
That may or may not work depending on the BIOS.
If the BIOS is written to address slot number one it might
stop the boot if it is vacant. Otherwise it may not matter.
I might have some 16 or 32MB memory but those might be in
a couple of IBM computers.

12 dram ic's on the module normally means it's parity. 60ns FPM was very common so there is a good chance it is that, but 72pin simms are electrically compatible regardless of whether FPM or EDO dram is used, so you shouldn't damage anything if you get it wrong.

Thanks for the replys.

There is only one memory slot. The control is proprietary there is no documentation on the computer portion. It's built into the display. It's actually quite a bit of work to get the memory out.

I didn't think about the bios, but I'm reluctant to turn the machine off incase it doesn't boot back up. Next time I have to boot back up I'll see if I can get into the bios.

Just to clarify when I mean the machine won't boot I mean nothing happens at all. A red error led lights up and the monitor doesn't display anything. If I leave it in this state for a while it usually boots up after I hit off then on again. I think something is warming up a little and then it works.

A few pics of the computer the last time we took it apart to see what memory was in it.

Edster said:

......If I leave it in this state for a while it usually boots up after I hit off then on again. I think something is warming up a little and then it works.....

Click to expand...

Not Toyokoki specific.....

Whenever I come across this type problem on a machine the first thing I do is put a scope on the power supply (supplies) to check voltage and noise. Very frequently I'll find either a missing voltage or lots of noise. Usually related to a failing electrolytic capacitor.

There are a couple power supplies and we checked the voltages but I never tried a scope on them. Might be worth a shot. The machine is a 2008 and it's had the problem for about 10 years. Just recently it started getting worse.