2nd hand A4000 does not show Fast Mem. How come ?

[Acill]

The first thing you need to do is get an A4000 COMPATABLE 2MB simm for the chip RAM. I would say its that RAM you have causing the trouble. Call a few shops and see what they have. I bet you can get one thats good for the system.

[Effy]

Acill : I happen to live in Belgium, a little country that you can cross from one side to the other in less then three hours ... trust me, there aren´t many Amiga shops, actually none as far as I know .. it might even be better to search on Ebay ... but thanks anyway for the advice

[Lemmink]

All right to clarify the RAM and jumper thing once and for all:
Jumper 213 selects the Chip-RAM size. Set so 1-2 it will only accept a 2MB Module, set to 2-3 it will accept an 8 MB module useing only 2 MB. If you insert a 4MB module it will only be recognised as 1 MB.

Jumper 852 selects Fast-RAM size. Set to 1-2 it will accept 4 MB modules only, set to 2-3 it will accept 1 MB modules only

Though there is an undocumented feature thet when jumper 582 is set to 1-2 you could use two 8MB modules instead of 4 4MB module if you place them in bank 1 and 3.

If all this doesn`t help you have to face the fact that the leaky battery allready killed the Fast-RAM at some point.
Don`t bother with RAM on a Fastlane, DKB3128 or even on a ZII card. It is even slower then the A4000 motherboard RAM. Though it is a nice goodie if your accelerator is allready packed to it`s max of 128 MB. (I got an A3000T with 320 MB Fast-RAM using an DKB3128 and a fully populated Fastlane in addition to the 128 MB on the MKII)

[Effy]

Lemmink : jumpers were already set that way. I am not talking about 5 memory modules, just two, the chip and one single fast. I´ve got the chip mem working so far, but fast ram does not work yet. And the battery was´t leaking, at least not much ... any other options I know that the A4000 was totally taken apart because the owner first sold his turboboard ... now I added an original 68030/25 board ... and that Xcalibur board I bought on Ebay is not a Z3 memory board but one that adds memory to a 3640 board by having the processor mounted on this card ...

[darkcoder]

are you sure about the jumper 852?
In your previous post you wrote it was set on 256k.

If you post the chip code and number of chips per SIMM we can tell the size of the SIMM.

[Effy]

I have tried to set the jumper to 256K and later to 1 Mb to see if there was any difference ... but there wasn´t ...  :-(

[TjLaZer]

@Effy!

You said the battery was not leaking or at least not much. Well my batt was leaking very very little and it killed traces to the RTC which I repaired.  It does not take much acid to ruin the 4000!  On the 2000 it is a different story!  I had a batt leak all over the place and was very furry!  After the new batt install everything was fine!

[x56h34]

I would try out different 4MB SIMMs and see if they work. Maybe you've got a defective or a dirty SIMM. Clean the SIMM module contacts with a q-tip dipped in some isopropyl alcohol. The SIMM sockets should be sprayed with a PCB cleanser liquid in order to degrease any dirt on those fragile contacts, which you would otherwise break if tried cleaning manually with a q-tip or similar.

If this fails, then most likely your motherboard is cooked. :-(

[Effy]

The four Simms that I have tried to put into the Fast Ram sockets are :

-SecKMM5364103CK-6            KOREA 9743 H
-TOSHIBA THM321000AS-80       JAPAN 9314AAA
-SMART SMI5321000W-7 446005IN MADE IN USA
-IBM 4M 70ns P  p/n 71F010  FAU 92F0105

I have only tried them one at a time, no combinations so there can not be any conflicts ... seems I need to use the X-calibur after all to expand my memory from 2 Mb Chip to 2 Mb Chip + 128 Mb Fast Ram ...

[Lemmink]

When you have an X-calibur why do you even bother with the little amount of slow motherboard RAM.

[Effy]

Lemmink: ehm, I don´t have it yet, I paid for it but there is always the theoretical option that I won´t receive anything ... so meanwhile I try to use whatever I have got ...

[Effy]

Oops  :-o  I thought I had to worry but suddenly it seems I have to worry DOUBLE  :-o   :-o
I decided to leave that A4000 at the end of my desk and take another naked A4000 with all Ram sockets filled, 3630/25 and kick 3.0, no harddrive, only internal floppy and two external floppies ... I booted with Workbench 3.1 floppy and guess what I got : 2 Mb Chip mem and 0 Mb Fast mem  :-o
This is absolutely not funny  :pissed:
So I took my own older A4000 with kick 3.1 and 3640/25 and all Ram sockets filled too, and booted with the same Workbench 3.1 floppy and (lucky for me) it turned out to have the 16 Mb Fast ram ...
Those two A4000´s with no Fast ram have all jumpers set to the same setting, have same turboboard and were booted with the same floppy (workbench 3.1), and have both 2Mb Chip.Now what the f**k have I done wrong  :-?

[daniel_r]

The Amiga 4000 showing 0 fast ram, has it had its Powersupply replaced (well the internals of it).  Did you know if you replace the amiga powersupply and not correctly wire up the adapter that it will not show up the fastram on your mainboard.  Try swapping the powersupplies and try again.

[Effy]

Ehm  :-? I don´t perfectly understand what you mean. As far as I can see there´s still an orginal power supply of 145 Watt inside the desktop(s). If you mean that I must remove the power plug and put it back on again then I shall try to do that (doesn´t sound so difficult) ...

[Effy]

Daniel_R : I unplugged the power connector from the motherboard, turned the power supply on and off, and plugged the power connector back on.There is only one way to connect it so you can not create fireworks. Result : computer still boots up but still without Fast Mem ...  :pissed:
Theoretical all my spare Simms can be faulty, not very likely, but it is possible. So I took a working Simm from my third Amiga4000 that has 16Mb Fast Ram, and plugged such a working module into an A4000 that refuses to use Fast Ram.Result : still no Fast Mem ...  :pissed: Means that the problem is not the Simm module(s) but the computer itself ...
I tried to set the Rom Speed from 200 to 160 by moving a jumper next to the IDE port ... no difference ...
Anybody any other cool ideas that I don´t know (to be honest, I don´t know that much of A4000´s)

[TjLaZer]

@Effy

Don't be stubborn. Your slightly leaky battery has cause corrosion and ruined some traces to your SIMM sockets.