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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: redrumloa on February 09, 2004, 01:54:08 PM
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Last night I got an unpleasant surprise. My A4k I am doing the tower project with DIED:-( Everything was working fine, more or less, until I decided to plug in speakers. BOOM total death. Now it won't boot, or even get to the early startup menu. When I turn the computer on I get.
1)A light grey screen that doesn't change or do anything.
2)No HD or floppy activity.
3)The CD-rom acts completely dead when plugged in, won't even eject when the IDE cable is plugged in. If I unplug the IDE cable but leave power it seems normal and respons to eject.
4)Power supply test ok
I seriously doubt a coincidence, something about plugging in speakers caused the death. What blew? Does the A4k have mb fuses like the A3k? I'm going to try to dig out the old service manual, but I am hoping someone here can also give me some clues. I'd really hate to have to buy another A4k MB at this point:-(
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The first thing to do is don't panic.
The second thing is grab a cup of your fave working poison and strip the 4k of every add-on possible. Boot up and see if you get anything. If it boots ok add in one of the add-ons then try again.
You'll know this by now anyway, but it's the best way to see what's wrong. And if you're in a panic, you don't think of this :-)
When my A1200 accel's FPU is playing funny buggers I get the same symptoms as you. It could be something simple like this (well, "simple" it isn't, but better than a whole mobo going).
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@Vincent
I did this last night. I stripped it of everything except the A3640. NADA, i am worried :-(
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redrumloa wrote:
@Vincent
I did this last night. I stripped it of everything except the A3640. NADA, i am worried :-(
I blame the PSU.
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Hi red :-)
What kind of speakers have you plugged in? I hope it's a pair of self amplified model and NOT an ordinary one...
just for completeness, you used the motherboard audio out to plug it in, right?
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bloodline wrote:
I blame the PSU.
It's a converted PC AT power supply. It was working a-ok until I plugged in speakers. I tested the PS (no load) and it seems normal except the -12V seems to be -10.46V. That should be close enough?
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redrumloa wrote:
Last night I got an unpleasant surprise. My A4k I am doing the tower project with DIED:-( Everything was working fine, more or less, until I decided to plug in speakers. BOOM total death.
What do you mean by plugged in speakers? How did you plug them in? What types of connections?
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@redrumloa:
You dont happen to have the original A4000 PSU to try with?
/Patrik
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@voxel
Yes they are self power speakers. This A4k mb was modified by the previous owner. He/she removed the original dual rca connectors and wired in a connector to use PC speakers. It is definately the audio I plugged into. I wouldn't rule out a problem with the PC speakers, possibly energising the connector. They are el-cheapo generic PC speakers.
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patrik wrote:
@redrumloa:
You dont happen to have the original A4000 PSU to try with?
/Patrik
I have a flakey one, but yeah I will test later just for completeness.
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SilvrDrgn wrote:
What do you mean by plugged in speakers? How did you plug them in? What types of connections?[/quote]
See my other post on the speakers. The only thing I did wrong was I plugged the speakers in while the computer was on. I know this technically is a no-no, but who would have thought it really would blow something? :-?
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Well :-)
Plugging cables in the sound output plugs when the amiga is on SHOULD NOT be a problem as the Amiga sound circuitery and cinchs are made for.
You should investigate around the modified plug to eliminate possibles shorts, I suggest you mount some Amiga style plugs back instead of the jack the other used.
Making a small adaptator cable or soldering two male cinch connectors to the speakers cable would not be too hard to do :-)
if you find no shorts, it's possible that the sound mixer ic (near the output) or the audio capacitors might be blown :-(
A more horrible thing to might have happened would be the death of paula too :-(
You should pray for the shorts on the plug...
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This A4k mb was modified by the previous owner. He/she removed the original dual rca connectors and wired in a connector to use PC speakers. It is definately the audio
I have a few leads which go from phono to a 3.5 socket would not like modify the computer, is it possible when you pluged the speakers in the motherboard moved or it has shorted somehow to the case.I would also say check the pins in the psu are making good contact and there is no dry joints under the psu plug on the motherboard. :-?
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I think there was a thread on here a while ago about audio capacitors on the 4000 mainboard blowing up. If these were on the brink, maybe plugging in the speakers while the system was on was too much for them? Try checking those.
Any physical signs of damage to the board?
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Seems to me like a short-cut somewhere.
Last weekend I had a zorro card which shorted with the casing.
Resulted in the same symptons you mentioned,
gray screen, completely dead hd/floppy and exactly the same with the cdrom.
Try to remove the audiojack, and try again...
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I think there was a thread on here a while ago about audio capacitors on the 4000 mainboard blowing up. If these were on the brink, maybe plugging in the speakers while the system was on was too much for them? Try checking those.
I doubt it's the caps on the audio circuit. I had one go out, and the only thing that happened was that I lost one of the audio channels.
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Hard one to diagnose. You know about the color sequence (http://vbulletin.newtek.com/showthread.php?s=282ae2c1ace33d1a069c8c4cd755d91e&postid=43781#post43781) so I'd suggest sticking with that.
Somehow, it seems more like coincidence that the machine died when plugging in the speakers. (Although, it having one of those PC speaker connections, I'm not sure if an Amiga would have any issues with the speaker outs being shorted, which is a possibility with those plugs.) I'd make sure the connector hack is good. Then go for reseating stuff (including the cpu card.)
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WHOA life!!!! I got home today and unplugged EVERYTHING including mouse and keyboard. Now I am able to get the 3.1 rom requestor!! Thank god for that!
Ok.. Now to try adding one thing at a time to see what was causing me grey hairs..... Stay tuned....
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*Twilight Zone music plays*
Everything including sound is working. I suspect something overheated last night :-? The only thing I am noticing right now is a little flakeyness of the CD-ROM on the internal IDE. But the internal IDE is known to be flakey right? I am suspecting the A3640 may be flakey :-?
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I had an 4000D with this problem years ago (not audio related). Turned out to be a flakey PAL at location U209 on the A3640 board. A shot of freeze mist directly on that IC would cure it for a few minutes until it got hot again. I seem to remember that PAL was hotter to the touch than it should have been. I couldn't source a new one so I just replaced the board. Might not be your issue but the symptoms were the same.
Jeff
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Hmmm, Is it just me or do th eA4000 series seem to be cheap? I've heard of so many having problems here in the last year. I've never had any problems with my A3000 and its up 24/7 all the time. I'm glad I never got an A4000.
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Hmmm, Is it just me or do th eA4000 series seem to be cheap? I've heard of so many having problems here in the last year. I've never had any problems with my A3000 and its up 24/7 all the time. I'm glad I never got an A4000.
Naw.... That's nuts. If we just go by heresay, I currently have two perfect A4000s here, and one dead A3000 and one flakey A3000. So therefore, the A3000 is obviously garbage, and the 4000 is great. Of course, we both know this isn't true.
I say the 4000 has no better or worse durability than any other Amiga. Here's my theory on it....
A4000s are typically found stuffed with all sorts of cards and add-ons. Accelerator boards, SCSI cards, PCI risers, graphics, network, etc... 3000's certainly CAN be expanded out to this level, but aren't found that way as often. Of course, the more that is added into a computer, the more likely the power supply will blow.... Or some shoddy card will short out the system... Or who knows what else.... And, of course, anything that damages a CIA in the 4000 is a major problem, because they're surface mounted. (An A3000 with blown CIA is hardly worth posting about.... It's a 10 minute fix.) The surface-mounted chips make the 4000 a real pain to service, hence more people ask questions before trying to swap out components, etc... Thus, it looks like there are more problems with them, because more problems get posted.
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Sound fair to me. i am still glad I have a A3000 though! :)
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Ok it's definately an overheating problem of some sort. I am suspecting the 3640 is the culprit. I hope that is the case because the A3640 is only in there temporarily, I will be putting in the CSPPC tonight:-)
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But still, its amazing how much beating the amiga hardware can handle compared to pc hardware, i had an a2000 for 7 years without problems, and a a500 from 1987 to 1994, and it has been dropped on the floor atleast 2 times, spilt cola over the keyboard and lots of other things.
but when i started using pc`s 3 years ago, i have had nothing but trouble, 3 pc`s die, and those were taken good care of :-x
And those saying amiga hardware is expensive, think about having to replace pc`hardware 3 times as frequent, and it adds up....
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Hmmm, Is it just me or do th eA4000 series seem to be cheap? I've heard of so many having problems here in the last year. I've never had any problems with my A3000 and its up 24/7 all the time. I'm glad I never got an A4000.
I think the a4000 suffers because of the poor quality case that does not have much room for airflow.I am thinking of putting some coolermaster ram heatsinks on some of the chips in my a4000 and modding the psu for better airflow.
but when i started using pc`s 3 years ago, i have had nothing but trouble, 3 pc`s die, and those were taken good care of
none of my pc.s ive built have had any problems including the first amd 450 k6.stick to good motherboards like asus my jetway was good as well but my msi was crap.
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restore2003 wrote:
But still, its amazing how much beating the amiga hardware can handle compared to pc hardware, i had an a2000 for 7 years without problems, and a a500 from 1987 to 1994, and it has been dropped on the floor atleast 2 times, spilt cola over the keyboard and lots of other things.
but when i started using pc`s 3 years ago, i have had nothing but trouble, 3 pc`s die, and those were taken good care of :-x
And those saying amiga hardware is expensive, think about having to replace pc`hardware 3 times as frequent, and it adds up....
I can't say I have an awful lot of experience with PC hardware, having only owned this laptop. But it amazes my friends when we are playing a game on the CD32 and I tell them that it is over ten years old [both the quality of the games and the fact that its still going]
Cheers
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@Acill
My dear friend. My A4000 works without problems :)
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@AmiDelf
So does mine :-D.
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Check your voltages from your ps. Check the wiring on the spliced in speaker wiring. It's better to use the original connectors for the sound and use a Y cable to hook up pc speakers.
My dear old friend, my A4K works fine. It has a couple of broken clips on the motherboard ram slots and I had to remove the battery. Other than that it runs fine. I've taken it apart down to pieces on the table and put it all back together and then did it again. It's now in a Power Tower case with a Phase5 060 board with 72meg of ram so I don't worry to much about the broken ram clips on the motherboard. Considering I've had it since new in summer of 1993 when I upgraded from my A500 I bought in 1988 in think it was one of the best purchases as for as computers or concerned.
In 2000 a got my first pc and I've had to upgrade systems three times. It's just about time to upgade system or at least cpu again just to stay close to current.
gwalp