A4000 Problems

[jmmijo]

I posted the following on USENET specifically comp.sys.amiga.hardware and have received some feedback on it. I figured I'd see if the EAB could also help as this is beginning to fustrate me

"I've got an A4000 Desktop that has 16MB of onboard Fast RAM. The problem is that it only shows up now as 4MB, like the SIMM's are just 1MB each. I've tried replacing them with 8 different SIMM modules, still no go. It used to show 16MB of fast but now doesn't Not sure what to look for, I've tried removing the Zorro cards and still no go, haven't tried removing the daughter board yet to see if there's a problem there."

Any advice would be helpful, thanks

[th4t1guy]

Here's a bit from my a4000 desktop manual;
hope this helps!

Jumpers:

Chip RAM Size
J213:1-2 **. 2MB
closed

J213:2-3 .** 8mb (sot supported)
closed

RAM SIZE:
J852:1-2 **. RAM size 1 Mbit x 32
closed

J852:2-3 .** RAM size 256 Kbit x32
closed


Exapndable using SIMM sockets on motherboard to a total of 16MB (additional RAM above 18MB can be added using expansion slots)

speed: 80 nanoseconds or faster

type: page mode
organization: 256k x 32 (1mb) or 1m x 32 (4mb)



Amount of RAM

1meg
2
3
4
4
8
12
16

Simm Size

1mb
1
1
1
4
4
4
4
4

Banks filled

0
0,1
0,1,2
0,1,2,3
0
0
0,1
0,1,2
0,1,2,3

[jmmijo]

Thanks for the info, but no, this will not help as I do have a manual and this is a configuration setting. I've replaced the jumper block and swapped out the SIMM's with others to see if this was the problem and still no go. No matter what size module I use, they appear only as 1MB modules for a total of 4MB of fast RAM

Thanks again for trying, I'm thinking the mobo is hosed as I think we had a power spike/surge/brown out about 3 weeks back when this all seem to happen. I would guess that this may have fragged something that I've not been able to figure out yet

The strange thing is that everything appears to be working properly, no crashes or anything on the system when running software so I'm not sure what fragged if anything.