pioneer sa-6500 ii blown fuse - 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 13th June 2010, 01:30 PM   #1
diyAudio Member
 
Join Date: Jun 2010
Default pioneer sa-6500 ii blown fuse

Hi, I have a Pioneer SA-6500II and the two fuses next to the transformer and near the 2 large caps keep blowing up. I also noticed that one resistor (4.6 ohms) near the first transistor ( I guess it's a transistor as it has 3 legs) that is screwed onto the heat sink is burnt. If I replace that resistor, do you think it would stop blowing the fuses and start working? Thanks for your help.
  Reply With Quote
Old 13th June 2010, 03:25 PM   #2
llwhtt is offline llwhtt  United States
diyAudio Member
 
Join Date: Jun 2008
Location: SoCal
Resistors don't go bad on their own. A bad resistor means that there was too much current flowing thru it and whatever is causing the current to flow, bad transistor(s), maybe (probably), is going to be your problem. You can change fuses all day long and each time you do could be making the problem worse especially if you try bigger fuses as many people do. The amplifier is broken and needs service. Do you have a schematic and what experience do you have with electronics? Test equipment?

Craig
  Reply With Quote
Old 15th June 2010, 03:31 PM   #3
diyAudio Member
 
Join Date: Jun 2010
Maybe I'll just have my co-worker look at it. He is an electrical engineer and has all the test equipment. I did not want to bother him if it was only replacing the resistor.

I do remember that I used it once and there was no sound so I turned up the volume almost half way and that's when I noticed smoke come out. Then I noticed that the speaker wires came unplugged. Maybe because I moved the entertainment center. Could this have happened because there were no speakers plugged in and I turned up the volume?

Thanks
  Reply With Quote
Old 15th June 2010, 04:10 PM   #4
llwhtt is offline llwhtt  United States
diyAudio Member
 
Join Date: Jun 2008
Location: SoCal
Solid state amps "usually" don't care about having a load or speaker connected or not, tube amps on the other hand care very much.

Craig
  Reply With Quote
Old 15th June 2010, 04:14 PM   #5
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
This amp is probably over 30yrs old at this point and is a candidate for a full recap during the course of the repairs.
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote
Old 15th June 2010, 05:54 PM   #6
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
I would bet good money that the wires only partially came out and have shorted the speaker outputs. This is going to be an "expert" repair job.
  Reply With Quote
Old 16th June 2010, 09:39 AM   #7
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
The 4R7 burnt resistor is probably in series with the base of one of the outputs.

The outputs will be fried, and the drivers will also be fried. The emitter resistors for the outputs may be open, and the bias circuit may be damaged.
__________________
Candidates for the Darwin Award should not read this author.
  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
pioneer SA-6500 II problem udip Solid State 9 11th March 2011 10:06 AM
Pioneer SA 7600 II XXX Solid State 0 3rd February 2010 01:54 PM
Pioneer SA 6500 into a Numark Tt-200....left speaker going off randomly! Help! soma89 Solid State 3 13th November 2009 07:57 AM
fuse problem - pioneer sa-7500 pezza89 Solid State 5 26th January 2008 10:05 PM
Pioneer SA-5500 II and sennheiser HD 280Pro jawbreak Everything Else 0 22nd November 2005 03:17 AM


New To Site? Need Help?

All times are GMT. The time now is 07:09 AM.


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