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 2012, 12:51 PM   #1
diyAudio Member
 
Join Date: May 2011
Default JVC VN700 power off problem

Hi All,

I have a JVC VN700 which switches off after 12 mins or so of use. On re powering, it trips againg after a few seconds. Sounds like a component faliure but could do with some advice to save lenghthy check.

If anyone has experienced this problem or has any advice, I would be very grateful.

I have checked the amp without speakers and with one chanel only, same problem so I guess the output trans are ok?

Last edited by starks; 10th May 2012 at 01:52 PM. Reason: Additional information
  Reply With Quote
Old 10th May 2012, 01:57 PM   #2
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
On an amp this old, it is probably the effect of dried out electrolytic capacitors. Measure the DC voltage on the speaker terminals from cold, and you will probably find it is rising slowly to the point where some protect circuit trips.
  Reply With Quote
Old 10th May 2012, 02:16 PM   #3
jaycee is offline jaycee  United Kingdom
diyAudio Member
 
Join Date: Apr 2004
Location: Norwich, UK
Service manual here: JVC VN-700 | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine
  Reply With Quote
Old 10th May 2012, 05:01 PM   #4
diyAudio Member
 
Join Date: May 2011
Hi,

Thanks for the advice, very much appreciated as I don't have an electronics background just some basic knowledge through messing around with vintage valve amps.

DC voltage measured over 100mv on one chanel so I took out one of the what I think are the preamp boards (TAD809) to test and found the culprit. The other board measures around 38 in both left and right slots.

With my limited knowledge, I will start by changing the caps and move on to resistors. I will have to do some reading on transistors!

Thanks again for your help
  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
JVC Shelf Component System Power supply julianjym Power Supplies 18 26th July 2011 06:07 PM
JVC turntable speed problem Fonic Analogue Source 1 7th June 2009 11:37 AM
Problem with PPI amps - POP on power on and power off Onkel Alex Car Audio 8 19th October 2008 07:48 PM
JVC Problem johnboy89 Car Audio 2 21st November 2007 01:18 AM
JVC M-3030 power amp schematic? mikeks Solid State 8 2nd September 2006 12:17 AM


New To Site? Need Help?

All times are GMT. The time now is 10:48 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