Old Memory Board

[Washac]

Hi All


I opened the trap door on an Old 500 I have, inside is a Mem board with two rows
of chips, 8 in each row, there is also a small switch at one end. I assume this is a 1Meg
memory board with switch to switch in and out 512k of said memory ?

It also has a soldered in battery name of VARTA, this has small crystal stuff on it so
obviously knackered I would think.

Am I right in my assumptions above and can the board maybe be repaired ?

There is no make or model or anything on it.

Cannot test to see if it works at the moment got to dig out the power supplys and stuff
I have here somewhere first.


Thanks....

[alexh]

It is most likely a 512Kbyte FastRAM upgrade with Battery Backed up Clock and the switch is likely to be an on/off switch for the RAM.

It probably doesn't need any repairing. Just remove the battery and give it a clean.

[Washac]

Originally Posted by alexh

It is most likely a 512Kbyte FastRAM upgrade with Battery Backed up Clock and the switch is likely to be an on/off switch for the RAM.

It probably doesn't need any repairing. Just remove the battery and give it a clean.

Thanks, just opened another old 500 I have here and it has the same board without a battery...

[rkauer]

Pending on A500 version, the 512kb memory will shown as FAST or added up to the chip RAM.

Only when Amiga turned on and working you'll be able to read the amount on Workbench screen:

Either 800kb-ish chip RAM

Or ~500kb chip RAM + more than 400kb of FAST RAM.
____________________________________

green crystal stuff on battery is battery leakage: remove battery and do a thorough clean around it with a mild acid (I suggest vinegar or lemon juice).

Apply it and wait for around ten minutes, then wash the board with pure water and let it dry in a vented cupboard for no less than a week in your winter time.

[Washac]

Originally Posted by rkauer

Pending on A500 version, the 512kb memory will shown as FAST or added up to the chip RAM.

Only when Amiga turned on and working you'll be able to read the amount on Workbench screen:

Either 800kb-ish chip RAM

Or ~500kb chip RAM + more than 400kb of FAST RAM.
____________________________________

green crystal stuff on battery is battery leakage: remove battery and do a thorough clean around it with a mild acid (I suggest vinegar or lemon juice).

Apply it and wait for around ten minutes, then wash the board with pure water and let it dry in a vented cupboard for no less than a week in your winter time.

Hi


I thought it was battery leakage, I cannot try the boards as both the 500s I have here refuse to turn on

[rkauer]

As a final advice you can gently pry off all socketed chips from their sockets and then push them back. You'll hear a cracking sound (don't panic!).

The Agnus chip (the square one in a square socket) can only be pushed out using a PLCC extracting tool. After this operation turn the Amiga on again. Use the working power supply for the test.

[Washac]

Originally Posted by rkauer

As a final advice you can gently pry off all socketed chips from their sockets and then push them back. You'll hear a cracking sound (don't panic!).

The Agnus chip (the square one in a square socket) can only be pushed out using a PLCC extracting tool. After this operation turn the Amiga on again. Use the working power supply for the test.

Hi


Both Amiga's now working

Took the expansion boards out and all Ok with both machines.

[rkauer]

Time to re-insert them, maybe it is just a contact problem on the battery-less one.