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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Munchkin on January 09, 2019, 12:49:48 PM
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I've recapped my 500 and replaced the old PSU. Booting up without the harddrive controller (GVP HD8+) connected everything seems to work just fine. Boots up from floppy and everything I've tried works just fine.
However, when I connect the controller/harddrive something happens. At first the self tests seem to work fine, it flashes a few grey screens but then the power light starts to blink a few times, the screen turns momentarily black and then it reboots to do the same process over and over.
It worked before I did the recap end psu-replacement, just not very stable due to age and having been in storage for 20 years. So, something has happened that doesn't affect the computer when nothing is connected through the expansion slot.
Ideas?
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Hi,
If I remember right, been a long time since I threw out all my Amiga stuff, i remember having to have a GVP.scsi somewhere in there and maybe a GVP library. been so long since I traitored over to the dark side and not using an Amiga but maybe this hint will help out.
smerf,
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PSU issue perhaps? What have you replaced the old PSU with? Have you tried the old PSU again? Apologies for asking obvious questions.
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Hi,
If I remember right, been a long time since I threw out all my Amiga stuff, i remember having to have a GVP.scsi somewhere in there and maybe a GVP library. been so long since I traitored over to the dark side and not using an Amiga but maybe this hint will help out.
smerf,
Nah, it's not something like that. It worked before the renovation, everything was just a bit unstable.
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PSU issue perhaps? What have you replaced the old PSU with? Have you tried the old PSU again? Apologies for asking obvious questions.
A Meanwell RT65-B. It has worked fine for others so I doubt this is the cause as well. Can't try the old one I'm afraid, didn't think I would ever need it again so didn't note where the wires were soldered. No markings on it where which wire goes so. You live and you learn. :)
I doubt it's a serious problem since it boots up fine from floppy without the controller connected. I guess I just have to go through the process of checking each cap to make sure they're all properly soldered again. Gonna try and clean everything as well, even though I doubt a little dirt would cause this.
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Why not the RT-50B? It has stronger -12V.
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It's what I've seen others use and it was a lot easier to get hold of. But does it really? When I check on Meanwells site both state 0.5A on -12V.
Though. I removed the 68000 and mounted my VXL-30 (I have to redo one cap because it's to high so I can't really have that on but I used a lose socket I had to make the card clear just for now) and now everything works just fine. Boots up from floppy and harddrive with no issues.
So, it seems my 68000 is faulty somehow but it doesn't show until I connect the controller.
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Maybe the 68000 socket is a bit dodgy? Some of these plug-in expansions with thick pins can really knacker the socket.
Also, another thing to check on A500's is that slender piece of shield than runs along the side expansion slot - make sure there's no shorts or anything when the edge connector is in use.
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Maybe the 68000 socket is a bit dodgy? Some of these plug-in expansions with thick pins can really knacker the socket.
Also, another thing to check on A500's is that slender piece of shield than runs along the side expansion slot - make sure there's no shorts or anything when the edge connector is in use.
You might be right about the socket. Doubt that the shield had anything to do with it though, it would most likely have failed with the accelerator mounted as well then.
There is something not quite right with the computer though. Recap and a new PSU didn't resolve the instability, it behaves exactly the same as before. So, might get a diagnostic rom to test it with.
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I'd put lavender in my bath if it wasn't the side car socket.
Or, you might experience instability with ANY expansion card connected to the side car socket as maybe the socket is fine at the frontend, but the problem lies from the back of the socket to anywhere on the motherboard that handles signals from the expansion port.
Let's think about this.... time and money for a DiagROM or checking continuity from the back end of the connector to pretty much everywhere on the motherboard.
I would A) go for the DiagROM or, B) replace the expansion connector, or C) spring for a Rev6 motherboard.
BTW, do you know what revision motherboard you have? Let us know as the rev might give an additional clue.
Yo smerf, good to see you post up!!!! 8)
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It's a Rev 5 board.
Not sure what you mean with "side car socket" though, you mean the expansion slot?
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Have you ever used Keir Fraser's Systest? It's very comprehensive. It's a small executable that takes over the machine, and can also be downloaded as a bootable ADF image: https://drive.google.com/file/d/0B6F...RvOXVDd3M/view
Might give some insight.
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Have you ever used Keir Fraser's Systest? It's very comprehensive. It's a small executable that takes over the machine, and can also be downloaded as a bootable ADF image: https://drive.google.com/file/d/0B6F...RvOXVDd3M/view
Might give some insight.
Never actually heard about it. Thanks for the tip, I'll test that out. That link didn't work though.
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Have you ever used Keir Fraser's Systest? It's very comprehensive. It's a small executable that takes over the machine, and can also be downloaded as a bootable ADF image: https://drive.google.com/file/d/0B6F...RvOXVDd3M/view
Might give some insight.
Never actually heard about it. Thanks for the tip, I'll test that out. That link didn't work though.
Try here on GitHub.... appears to be an updated version too. ;)
https://github.com/keirf/Amiga-Stuff
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Have you ever used Keir Fraser's Systest? It's very comprehensive. It's a small executable that takes over the machine, and can also be downloaded as a bootable ADF image: https://drive.google.com/file/d/0B6F...RvOXVDd3M/view
Might give some insight.
Never actually heard about it. Thanks for the tip, I'll test that out. That link didn't work though.
Try here on GitHub.... appears to be an updated version too. ;)
https://github.com/keirf/Amiga-Stuff
Thanks, I found it myself eventually. Gonna try that and see.
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Well, did get some errors on memory test. Don't really know what to make of it though, my hardware knowledge doesn't go deep enough.
(http://www.sjolin.eu/DSC_0198.JPG)
(http://www.sjolin.eu/DSC_0199.JPG)
Besides this nothing seems to be wrong according to Systest.
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It's pointing out some faulty Fast RAM on your GVP. Can you re-seat all the RAM and test again? I presume you pressed F2 and it completed with this final screen pointing the errors out?
Edit: Well, at least I think it is (having never used the software nor read the docs!)
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As far as I can figure out it points at the memory on the RAM-32 on the VXL-30, that's the address space at least.
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Ah I see, you have the GVP and VXL hooked up together.
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Exactly. THough, testing further I get errors on the 4 MB on the gvp controller as well so those might also be bad. That might explain why the computer crashes with only the gvp connected, the faulty ram is accessed as it tries to boot. Going to swap around the memory sticks on it to see if anything changes. Wonder where one can find 120ns 30 pin Simms these days.
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How do you remove the 30 pin simms without destroying the sockets? It's been 25 years since I installed them, I just don't remember how and since all slots are populated I can't see what it looks like underneath. I see some "notches" in the holes of the simms but trying to push them down doesn't seem to make things easier. It's like they're welded in place.
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Anyone?
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I managed to remove the simms. I've cleaned everything up and I still got errors.
Though, I think something's a bit fishy here. I remember I ordered my HD8+ with some ram so two of the simms were installed when I got it. I can't remember if I ordered it with 2 or 4 MB though.
Later on 2 more simms were added, I don't remember if it made any difference though.
THe Amiga have read it as 4MB ram though. However, now that I removed them all and cleaned things upp as much as I could I reinstalled two simms and moved the jumpers to the coorect positions. After booting up it still says 4MB. So I changed to the other two simms and the same thing. I located the manual and read a bit. Noticed that the J12 jumper was in the wrong position, it was set for 8MB, so I moved that to the correct position. After reboot here I got a startup error claiming the board was faulty. So, I'm a bit stumped as to what's wrong with these simms, or if it's the board somehow.
Removed all simms and moved all jumpers to 0MB position and everything booted fine.
Including a pic of the simms I have. I have no clue about how to determine the size of them. I'm not surprised that the system have been unstable since this clearly has been wrong from the beginning. My 500 did always crash a lot when using larger amount of ram. The fact that it's been more unstable since I unpacked it again is probably due to some failure with the 32-bit ram that wasn't there before.
So, can anyone tell me what sizes these are?
(http://www.sjolin.eu/DSC_0204.JPG)
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According to this (https://www.datasheetarchive.com/pdf/download.php?id=9c9d2a6770fafe71036593cbf8e96ed3d06762&type=O&term=791000NS) sheet the goldstar modules are 4M bit.
edit: corr. typo :D
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Yeah, I guessed they are 1 MB simms but from what I could dig up myself I wasn't quite sure. Don't know what's wrong though since the GVP controller doesn't accept them as such. It seems more likely that it's the controller that's broken somehow. The SCSI interface works just fine, the memory part not so much.
Oh well. Hope I can find some other simms to test with. Seems to be some on ebay so might give it a try with 2x4MB
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Hmmm... GVP you say...
I dont know if it apply to the one gvp you got.
But i do recollect that gvp was wery picky about ram sticks. and/or only accepted gvp simms....
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That's the 64 pin simms that were used in some other products.
No, either all of my simms are bad or there's something wrong with the board. Need to find some replacement simms to check.