Sansui AU-9500 trouble - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 10th May 2007, 06:49 AM   #1
diyAudio Member
 
Join Date: Feb 2006
Location: Manila
Send a message via MSN to markmlists
Default Sansui AU-9500 trouble

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
  Reply With Quote
Old 10th May 2007, 07:08 AM   #2
Netlist is offline Netlist  Belgium
diyAudio Moderator Emeritus
 
Netlist's Avatar
 
Join Date: Jan 2003
Mark,
No doubt more help could be given if a schematic was at hand.
eserviceinfo.com has it. Try to get it and return here with part numbers.

/Hugo
  Reply With Quote
Old 24th May 2007, 05:34 AM   #3
steve_v is offline steve_v  New Zealand
diyAudio Member
 
Join Date: Sep 2004
Location: Dunedin
Send a message via MSN to steve_v
I would first do the obvious and replace the caps, they will be pretty cheap.

I have the full operation / service manual, but I don't know what the scan quality would be like as it is a photocopy of a photocopy...

Cheers,

Steve.
  Reply With Quote
Old 24th May 2007, 06:04 AM   #4
diyAudio Member
 
Cloth Ears's Avatar
 
Join Date: Dec 2001
Location: Melbourne, Australia
Sansui forum.
__________________
Jont.
"It is impossible to build a fool proof system; because fools are so ingenious."
  Reply With Quote
Old 24th May 2007, 08:22 AM   #5
diyAudio Member
 
Join Date: Feb 2006
Location: Manila
Send a message via MSN to markmlists
Default 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
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hitachi HMA-9500 Roar Malmin Solid State 0 5th December 2008 03:41 PM
ScanSpeak 9500 Rybaudio Swap Meet 9 15th July 2008 02:20 PM
Best match for SS 9500 henriksommer Multi-Way 5 4th March 2004 11:47 AM


New To Site? Need Help?

All times are GMT. The time now is 11:12 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2