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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: tokyoracer on February 03, 2008, 11:54:30 PM
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Hello again,
Sorry to keep coming up with more dissapointing crap as it seems i'v been very unlucky recently, though this time something more serious has happend. I recived an A4000/040 fairly recently but havn't had the time to set it up completely until now and noticed it doesn't boot up at all. The floppy LED stays on but nothing else. I hear the HD boot up too but not actually reading anything. I'v taken out the CV64 and all the RAM cards but it makes no difference. If tried all i can but im just stuck what to do now and having to resort to outside help. Has anyone got any ideas?
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Remove the CPU card and reseat it. Also check for a leaking battery or one that had leaked in the past.
I would also check the CPU jumpers make sure they are on EXT.
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Ok just done that. Removed the 040, daughterboard, (battery already removed), all ram cards but is still the same.
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You say the floppy light stays on all the time? The ribbon cable isn't backwards is it? Pull the cable to the floppy and see it you get video.
Jeff
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Nah it still displays a blank screen. :-(
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If you continuously press the caps lock, does it stay lit?
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No, oddly it works a few times then it says off. :-?
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in what position are the jumpers under the A3640?
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Then the processor hasn't even initialized :-(
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If you wait a few mins I can do a scan for you.
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Scan ready: http://i33.photobucket.com/albums/d74/celliot/Scan10035.jpg
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Bog standard 25MHz A3640 v3.1, MAPROM enabled.
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@ Alexh, looks spot on.
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CAPS (http://joj.home.texas.net/amiga/amiga00.html) !
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and another site about replacing capacitors:
A3640_capacitor (http://amiga.serveftp.net/A3640_capacitor.html)
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tokyoracer wrote:
...havn't had the time to set it up completely until now and noticed it doesn't boot up at all.
As said above already: remove and reseat the CPU card, and clean the contacts. I had the same trouble with my old (and now your) A4000, and after reseating the CPU card twice and with a slight bit of pressure it booted up.
I think the problem might be in the CPU connector on the mainboard - if (one of) the pins in there are slightly bent back then it doesn't boot up. Examine those pins and when needed, gently bend them back with a small pointy thing (like a needle).
Really, your A4000 is in working order, she just needs some TLC.
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My money would be on the connector (blow it out with canned air), or capacitors. From your picture, they do look like they've leaked as the solder is all tarnished beyond the norm.
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Yes but this machine wont boot up, even without the card inserted so it can't be that.
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An A4000 doesn't bootup without a processor card installed, so if it's faulty, it won't boot up. It doesn't have a processor on the mobo. (some A4000s did have a 030 on the mobo AFAIK, but I don't think yours does(they're kind of rare). do you see a 030 ?)
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Do I see an 030? I don't quite catch you on that. But I will have another good look at the 040 board, would you know who I can send it to to get repaird if needed?
Oh and if it is the contacts, what should I clean them with?
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Look on the A4000 motherboard. If you have an 030 processor on board, then you can boot your A4000 without a CPU card inserted if you set the jumpers correctly. If you don't have an on-board 030 then there is no way of getting the machine to boot without a CPU card inserted.
--
moto
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tokyoracer wrote:
Yes but this machine wont boot up, even without the card inserted so it can't be that.
Well, that's pretty logical: there's no computer in the world that boots without a CPU :-)
Do I see an 030? I don't quite catch you on that.
The A4000 rev.D had an onboard 68030. Yours is a rev.B, so yours doesn't.
But I will have another good look at the 040 board, would you know who I can send it to to get repaird if needed?
Don't rush things before you are absolutely sure. I sent you the A4000 after I tested it and it WORKS. Just be a bit patient, clean the contacts of the CPU card, reseat it, press it down gently (you can even try pressing it down while powering up the machine - I did that as well, just don't touch any metal parts and make sure you are properly grounded). I'm 100% sure this machine works, it's just some quirky contacts with the CPU card.
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UPDATE: I have the pink screen of death. 7 "256" items have been listed as defective.
2nd boot, Plain white screen.
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tokyoracer wrote:
UPDATE: I have the pink screen of death. 7 "256" items have been listed as defective.
Try booting with only the CHIP ram SIMM installed?
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@ McVenco, will do!
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IT'S ALIVE!!! :-D A loverly animated disk has appeard. Thanks ever-so-much for all your help! You call all probably see im no otpamist. :roll:
[EDIT] And the HDD is fine. ^-^
[EDIT 2] Still a few issues remain, FDD light is still on constantly and it doesn't like the CV64.
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The SMD caps have leaked. Replace them ASAP.
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I recall that some of the caps on the A3640 have to be installed BACKWARDS from the silkscreening to be correct. Isn't that right?
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Yup. Many links already given to instructions - it's not *every* capacitor tho :D
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TjLaZer wrote:
I recall that some of the caps on the A3640 have to be installed BACKWARDS from the silkscreening to be correct. Isn't that right?
Right-O!
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Well I looked at them all but I cant see any real signs of leeky caps, they all look ok but im worred that the sound has gone iffy and it keeps yellow screening when I installed new SIMM RAM. Not to mention it comes up with various different RAM sizes upon startup but never the right ammount (8MB).
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Sound iffy = leaking caps.
http://amiga.serveftp.net for instructions on how to fix.
RAM troubles = possibly damage from battery leak... Clean, clean and clean again, and cross fingers? :)