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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Fester on November 21, 2006, 06:09:23 PM
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Hi there,
The sound on my Amiga 2000 just stopped working suddenly. There's no sound to the 1984's speaker and the RCA out is dead silent too.
Fester
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Does your floppy drive still work? It might be that the Paula chip is having problems. Otherwise it might be something in between the Paula chip and the sound output jacks (I'm not sure if there is some sort of pre-amp to bring the sound to line-level or not).
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Paula probably is it. On the other hand... a drastic change in weather could cause sudden corrosion on connectors. So you could try some contact-spray on both the connectors on the A2000 and 1084. Have you tried a known good audio cable?
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Hi there,
I tested with good audio cables. My floppy disk drives, two internal and one external all work fine too. So if the Paula chip is on permanent vacation, does anyone know if is it easy to replace?
I'm asking before sending it somewhere...
Fester
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It could even be a problem with the -12V line of the PSU. If the PSU is lacking -12V or the current is somewhere interrupted, the result is broken audio (most of the rest is working fine). I once had exactly the same problem.
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humppa wrote:
It could even be a problem with the -12V line of the PSU. If the PSU is lacking -12V or the current is somewhere interrupted, the result is broken audio (most of the rest is working fine). I once had exactly the same problem.
Cool. I could tinker with that. I have an extra PSU.
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Cool. I could tinker with that. I have an extra PSU.
Or measure the old PSU before removing it. Alternatively, you could check for -12V on the serial port (Pin10).
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No battery leaking either?
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I have recently experienced weather effects on my A600's audio : since a night spent in a cold room with open window, the right audio channel sometimes goes out or makes noises, and on this right channel the audio filter has no effect anymore.
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Low temperatures and high humidity never are good things to have a computer operating in. Make sure it's dry again and use little contact-cleaner to get out any damp on the connectors.
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arkpandora wrote:
I have recently experienced weather effects on my A600's audio : since a night spent in a cold room with open window, the right audio channel sometimes goes out or makes noises, and on this right channel the audio filter has no effect anymore.
My sound just died instantly between reboots. It went from working to not working at all. There's some good suggestions in this thread. I'll be tinkering with this over thanksgiving. Thanks all!
Fester
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The Paula for an A2000 is not too hard to find. In fact, you can use a Paula from an A500, which are very common on Ebay (and not too expensive). I'm sure some Amiga dealers also have the Paula chips themselves for sale.
Actually, I think the Paula chip remained virtually unchanged in all the Amiga models....so you might be able to use any Paula chip in your A2000. But check into this before you use one not from an A500/2000.
Also, try reseating your Paula chip (just press down on it after you have grounded yourself to prevent static electricity from ruining it). It might have become unseated through the years (temperature extremes, vibration, etc.).
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Fester:
Did the machine reboot at will or did it decide to reboot all by her self? If the decision was made by the Amiga and not by you pressing the three keys then you're into a nice little puzzle :-(.
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amiga_3k wrote:
Fester:
Did the machine reboot at will or did it decide to reboot all by her self? If the decision was made by the Amiga and not by you pressing the three keys then you're into a nice little puzzle :-(.
No the machine didn't reboot on it's own. I just noticed the sound was dead the next time I used the computer.
I ordered a new Paula chip from softhut.com just in case. The motherboard and chip are clean. There doesn't seem to be any seating problems or looseness. I'll test PSU voltage sometime today when I get around putting a new battery in my meter.
Fester
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Is it possible that the RCA contacts on the motherboard are cracked?
The Wizard
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This might seem obvious, but have you ruled out your speakers as the cause of the failure?
Have you tried the Amiga with all new cables & speakers?
Is there a Digital to analogue convertor between the Paula and the RCA outputs? I'm just thinking, if it's not the Paula, and not the jacks, cables or monitor, and not a software problem, then it must be something in between the Paula and the RCA jacks. Maybe a line-level pre-amp or D/A circuitry. Maybe just a dead capacitor or resistor or something. Anyway, it sounds like this Amiga can be fixed if you're willing to put out a little cash or effort.
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Hi There,
Thanks for all the input. I don't know what this means exactly, but there seems to be a power problem on the serial port. The A2000 manual shows PIN 10 as -12V. My meter reads -11 volts, which is close enough. But when I try Pin 9, which is described as +12, I get a 1.6 volt readout on my digital meter.
As far as the Paula being dead, I am not sure yet. I'll try replacing it when the new chip arrives.
If it turns out that replacing the Paula and the PSU doesn't help, I might just send the motherboard somewhere.
Fester
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ral-clan wrote:
This might seem obvious, but have you ruled out your speakers as the cause of the failure?
Hi, yes I have. I tried a different set and tested both the monitor and the other speakers with a different input device. They work fine. The cables and speakers and monitor all work.
Oh well...I can try switching Paula and PSU. After that, I'll just send it somewhere...
Fester
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Ok, but test your Amiga with a different power supply before you try the new Paula chip. You don't want the new Paula chip to be damaged if there is a problem with your original power supply.
Sorry to hear of your problems. We've all had them. But I do think that getting Amigas fixed (repaired) rather than trashing them is a good idea, even if it is slightly costly. The supply of A2000 motherboards is finite. Every time a user trashes one rather than going the extra mile to get it repaired means one less A2000 out there! They may still seem plentiful on Ebay at the moment, but they aren't getting any cheaper there either (which is amazing for a 15 year old computer, ain't it?).
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ral-clan wrote:
Ok, but test your Amiga with a different power supply before you try the new Paula chip. You don't want the new Paula chip to be damaged if there is a problem with your original power supply.
Absolutely. Good point.
ral-clan wrote:
Sorry to hear of your problems. We've all had them. But I do think that getting Amigas fixed (repaired) rather than trashing them is a good idea, even if it is slightly costly. The supply of A2000 motherboards is finite. Every time a user trashes one rather than going the extra mile to get it repaired means one less A2000 out there! They may still seem plentiful on Ebay at the moment, but they aren't getting any cheaper there either (which is amazing for a 15 year old computer, ain't it?).
Very very true. I could just buy another A2000 mb on eBay, but I want to fix this one. Just cuz...
Fester
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The low voltage on pin 9 is indeed a little thing that could make you worry. Have you checked all other functions of the Amiga? I'm thinking of fully functioning mouse / joysticks, floppydrives, printer? If it's Paula, chances are that mouse / joysticks are mis-behaving. CIAs can (and in many cases do) cause sound/serial related errors as well. So, make sure the PSU is okay and also check for short-circuits. And... check ground! Currents tend to flow in the direction of the least resistance. If the normal ground connection is corroded causing a bigger resistance then, say, the audio-ground then the currents will take that route, making a total mess of your system.
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Greetings,
I found the problem. It's my monitor and my own stupidity. I didn't test it properly. I don't know how I missed this but I did.
The A2000 sound is fine. It works as it should. My 1084's sound however, that's another story. I will add external speakers.
Nevertheless, it wasn't a total waste of time to open the Amiga box and look inside. I upgraded it to 3.1 ROMS and seated my two internal floppies properly so they appear straight in the casing window. I also whiped out the hard drive and loaded OS 3.1 and a bunch of software.
Fester
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Great glad the old 2000 is fine. Did you check the battery and remove it? :P I recently got a nice 2000 and the battery was leaking so I removed it just in time. No battery in it now but there is no need for one really.
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TjLaZer wrote:
Great glad the old 2000 is fine. Did you check the battery and remove it? :P I recently got a nice 2000 and the battery was leaking so I removed it just in time. No battery in it now but there is no need for one really.
Hi TjLaZer,
As a matter of fact, there was no battery in there when I purchased it off eBay. I ordered a new battery from AmigaKit last week just for fun. My Amiga displays dates in the 1970s. I assume that has to do with the absence of the battery.
Fester