Hi,
Need assistance about my recently acquired au9500. I bought this last week after many years of storage.
Last Night, after playing at low volume for about 3 hours, my todler accidentally turned the volume knob to about midway increasing the volume substantially. By the time I reached it, something in the unit popped causing the power to cut off with a white smoke (unburnt smell, fuse glass is not black-the filament just cut).
Troubleshooting done:
1. Upong closer inspection, one the left speaker fuse blew (one of 4. Main fuse is ok).
2. I checked the top of the unit cover off and there was nothing that was discolored.
3. I then removed the bottom cover and saw 1 3.3uf 100V electrolytic busted (guts out cut in half). This capacitor is connected to one of the terminals of the driver board socket.
4. I checked all the diodes and capacitors there and they seemed ok. I dont know how to check the 2 VR's though.
Questions:
1. Is this just a case of dried-long stored caps shorting out because of the sudden increase in volume and replacing them along with the fuse would fix the problem?
2. Is it just a dc filtering cap (they have 2 of those caps per channel-at the bottom of the unit)? If it is a dc filtering cap, can I replace them with non polar types (film caps or non polar electrolytic)?
3. Can I increase the value of this cap to higher voltage?
4. Any troubleshooting steps you could suggest is appreciated.
Many Thanks!!!
Mark
Need assistance about my recently acquired au9500. I bought this last week after many years of storage.
Last Night, after playing at low volume for about 3 hours, my todler accidentally turned the volume knob to about midway increasing the volume substantially. By the time I reached it, something in the unit popped causing the power to cut off with a white smoke (unburnt smell, fuse glass is not black-the filament just cut).
Troubleshooting done:
1. Upong closer inspection, one the left speaker fuse blew (one of 4. Main fuse is ok).
2. I checked the top of the unit cover off and there was nothing that was discolored.
3. I then removed the bottom cover and saw 1 3.3uf 100V electrolytic busted (guts out cut in half). This capacitor is connected to one of the terminals of the driver board socket.
4. I checked all the diodes and capacitors there and they seemed ok. I dont know how to check the 2 VR's though.
Questions:
1. Is this just a case of dried-long stored caps shorting out because of the sudden increase in volume and replacing them along with the fuse would fix the problem?
2. Is it just a dc filtering cap (they have 2 of those caps per channel-at the bottom of the unit)? If it is a dc filtering cap, can I replace them with non polar types (film caps or non polar electrolytic)?
3. Can I increase the value of this cap to higher voltage?
4. Any troubleshooting steps you could suggest is appreciated.
Many Thanks!!!
Mark
thanks
Thanks for the input guys. I replaced the caps then bought it to a tech for further troubleshooting and opt replacement. Its now sounding well now. I read 1 article in audiokarma about a similar problem but cant ask/post as registration is not allowed for now. 1 kind soul sent me a schmatic and will review further to troubleshoot more if needed to avoid it happening again. . will keep you guys posted. thanks
Thanks for the input guys. I replaced the caps then bought it to a tech for further troubleshooting and opt replacement. Its now sounding well now. I read 1 article in audiokarma about a similar problem but cant ask/post as registration is not allowed for now. 1 kind soul sent me a schmatic and will review further to troubleshoot more if needed to avoid it happening again. . will keep you guys posted. thanks
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