View Full Version : 2nd hand A4000 does not show Fast Mem. How come ?
I have an A4000 desktop here (one of three) with an original 68030 and superbuster 9 and a battery that looks not like a disaster. I donīt see any traces of acid on the board, though the battery itself has some corrosion (?) on it but this can be removed by using a strong toothbrush.
When I tried it it refused to boot up, giving a green screen and once in a while blink and then gave again a green screen.
So I opened it up and saw the problem : no Ram. So I searched in my cigar-box with Ram modules and after trying a few times the A4000 finally booted up giving 2 Mb Chip. Cool !! But the problem started at this point when I tried to add Fast Ram. This is until now still not recognized. I use modules of 4 Mb and 8 Mb, one at a time and this at every place I can put a module in (4). The modules itself can not be faulty, not all of them. So what am I doing wrong ??? There is no harddrive connected, only floppy, and it does boot up from that one ... there is also no Zorro card inside ... have I forgotten something ???
Is this one of those "things in life that can happen" ??? Does this mean that the only way to add Fast Ram is a turboboard or a FastLane scsi controller ??? I do have got a FastLane (from Ebay) but I havenīt tried it yet ... and I have no turboboard ...
06-07-2004, 08:15 AM
Well, there should be a jumper to choose between 1/2 MB simms and 4/8 MB simms. The Chip simm should be 2 MB. If you are using 8 MB simms only alternate positins could be used, to a total of 16 MB.
06-07-2004, 08:32 AM
Get rid of that battery off of the motherboard as soon as possible! No matter how much cleaning you do, it won't be enough. Replace it with a Lithium coin batter any a diode (to prevent charging). Or hook wires up in the battery's place and mount a new one somewhere else off of the motherboard (that's what I did).
06-07-2004, 08:42 AM
Yep. The CHIP ram needs to be a 2MB simm in Bank 0. The Fast RAM should be in banks 1 and 3 if you are using double-sided simms, or in banks 1,2,3,4, if you are using single-sided simms. And I do believe there is a jumper to set for the 1/2 or 4/8 SIMM sizing. And, most likely, single-sided 8MB SIMMs, or double-sided 4MB SIMMs aren't compatible, and will be detected wrong.
I think that was the lessons I learned on A4000 RAM setup. ;-)
Warren Block's A4000 hardware page (http://wonkity.com/~wblock/a4000hard/main.html) is an excellent source of knowledge.
I have tried several Simms, 4 Mb,8 MB,16 MB, and this in bank 1 to 4, which means I had to do a lot of replacing. None of them works, only the chip mem works and this turns out to be 2 Mb when I get into the workbench...
Did some more experimenting. It turned out that the module for chip ram was a 16 Mb or 32 Mb, so I decided to replace it by a smaller one because after all only 2 Mb will be used. So I tried some modules that looked like 4 Mb or 8 Mb. Turned out I got only 1 Mb or even 512 K Chip Mem !!! Totally uncool !!! Continued to experiment with other modules and after using a very small module that didnīt seem to have many chips on it, I got my 2 Mb Chip Mem back.
Then I continued to get the Fast Ram to work, but no results. At this moment I have in bank 1 and 2 two identical modules that may be 4 Mb maximum. Now two jumper settings:
-jumper 214 : set to VBB and not to 1 8M
placed to the upper left of the buster chip
-jumper 852 : set to 256Kx32 and not to 1x32
placed almost under the daughterboard close to chip mem module
My A4000 has a motherboard Rev B
Any cool advice would be very welcome, especially because of the burning sun outside ...
06-07-2004, 11:28 AM
Any cool advice would be very welcome, especially because of the burning sun outside ...
Grab a crate of beer and get out, drink your troubles away if necessary. Wait till next rainyday with your memory-woes.
06-07-2004, 11:49 AM
Yes, I believe you should use exactly a 2MB simm for your chip RAM. Others may work, but return unexpected results. I have heard that this has to do with various sized SIMMs using different internal addressing systems. The Amiga is expecting a single-sided 2MB SIMM in bank 0. Anything else is a crapshoot as to what will happen.
-jumper 852 : set to 256Kx32 and not to 1x32
This should be set to 1x32. That allows 4MB and larger simms.
(After all a 4MB SIMMs is 1MBx32bit.) ;-)
Morley : I am already trying to do the job with italian red wine ... :-)
Ilwrath : so it could be that the not-2Mb-chip in the chip mem bank causes the other memory banks not to work :-?
06-07-2004, 12:29 PM
so it could be that the not-2Mb-chip in the chip mem bank causes the other memory banks not to work
I don't know. I've never tried anything other than a 2MB SIMM. I don't *THINK* it should interfere with other RAM, but I'm not sure. More likely, I'd think it would just result in mis-detected CHIP RAM size (which you've had) or corruption and errors in CHIP RAM, causing gurus, unbootable, etc.
But, for sure, the 1x32 jumper should be set, to use any SIMM larger than a 2MB in fast RAM. Also, the SIMMs used in fast RAM should all be the same size and style. (in other words, don't use a 4MB and a 8MB together, and don't mix single- and double-sided SIMMs.) I always keep the same speed and manufacturer on all SIMMs, as well, but probably not necessary.
At the moment those three Simmīs that are placed are all three single sided and probably not bigger than 4 Mb each ... but I shall check on that jumper ...
06-07-2004, 09:27 PM
Sounds like you have some traces bad. I had a leaky batt in my 4000 and it was very minor but the RTC was dead due to some traces corroded, but RAM is ok. Since the SIMM slots are real close to the batt this may be the case for you. Good luck.
The pitty side of this A4000 is that is has got superbuster 11 and kick 3.1 ... but maybe I can transfer an 68040/25 from another A4000 to this one and use this when I get it :
X-calibur (http://cgi.benl.ebay.be/ws/eBayISAPI.dll?ViewItem&item=3482972111&sspagename=STRK%3AMEWA%3AIT&rd=1) ... which will allow me to use up to 4x32 Mb Simmīs !! That way there will be no īslowī fast memory on the motherboard that may slow the system down :-)
06-08-2004, 12:39 PM
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.
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 arenīt 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 :)
06-09-2004, 09:29 AM
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)
Lemmink : jumpers were already set that way. I am not talking about 5 memory modules, just two, the chip and one single fast. Iīve got the chip mem working so far, but fast ram does not work yet. And the battery wasīt 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 ...
06-11-2004, 10:43 AM
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.
I have tried to set the jumper to 256K and later to 1 Mb to see if there was any difference ... but there wasnīt ... :-(
06-11-2004, 12:47 PM
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!
06-11-2004, 12:57 PM
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. :-(
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 ...
06-11-2004, 03:22 PM
When you have an X-calibur why do you even bother with the little amount of slow motherboard RAM.
Lemmink: ehm, I donīt have it yet, I paid for it but there is always the theoretical option that I wonīt receive anything ... so meanwhile I try to use whatever I have got ...
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 A4000īs 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 :-?
06-12-2004, 05:52 AM
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.
Ehm :-? I donīt perfectly understand what you mean. As far as I can see thereīs 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 (doesnīt sound so difficult) ...
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 donīt know ??? (to be honest, I donīt know that much of A4000īs)
06-12-2004, 12:27 PM
Don't be stubborn. Your slightly leaky battery has cause corrosion and ruined some traces to your SIMM sockets.
TjLaZer : I just donīt like to give up so easy ...
06-12-2004, 04:08 PM
Yeah I know. But it seems you have done a good job troubleshooting. It seems the SIMMs sockets are not registering the RAM so a trace must be broken. You could always send it off to Amiga.fr to get repaired. They are reasonably priced and very fast!! I had them repair a dead 4000 MB recently and I got it back in 3 weeks! Or you can try to fix the traces if you have the skill.
06-17-2004, 02:57 AM
I can't understand anything from the SIMM number you posted.
Are these the numbers written on the chips? I need the numbers on the chip themself, not the number written on the simm.
Anyway, since your 3rd 4000 has fast memory, have you tried to remove one working SIMM from the 3rd (which works for sure) and put it in the other ones? (with the same jumper setting as the working 4000)
In this way, if you still have 0 Fast mem, it's clear that the motherboard or the simm slots are dameged.
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