Advice in Yamaha PC2002 - 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 29th August 2008, 05:42 AM   #1
diyAudio Member
 
Join Date: Aug 2008
Default Advice in Yamaha PC2002

Hi,im in trouble with one chanel of this amp,when i get this amp the B channel has repared, i use it for a while and the B chan burn (litteraly with sparks fog etc etc),so i fix it with motorola MJ15022/23 for the output replace bad R's drivers etc and it go good in bias& offset ,again go on fire after two hours ,but this time under" ligth load" (listen in livingroom),i realize that the MJ's are fake,again replace everyting bad but this time whit ON SEMI's parts direct from they, everyting ok bias etc and...again on fire....after few hours low volume etc etc.i got new parts and i m ready to go again but i m looking for advice (or a good fire stinguisher).so please if any can help....
Attached Images
File Type: jpg mj15023-2.jpg (75.4 KB, 78 views)
  Reply With Quote
Old 29th August 2008, 05:44 AM   #2
diyAudio Member
 
Join Date: Aug 2008
The good ones that burn in the second round
Attached Images
File Type: jpg mj15023g-2.jpg (75.9 KB, 71 views)
  Reply With Quote
Old 29th August 2008, 05:52 AM   #3
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
may be some oscillation
= unstability, which in the end will corrupt the output and overload it
This can have several reasons.

- The input filter capacitance can not stop RadioWaves from enter amp
- The compensation capacitance is too low (small caps to reduce HF gain)
- The Zobel output filter is not working. 1 cap + resistor across output.


One question:
When you turned on the amp, after changing Transistors,
how hot was the heatsink, close to Output Transistors?
Without any signal at input.
__________________
lineup
  Reply With Quote
Old 29th August 2008, 05:54 AM   #4
diyAudio Member
 
Join Date: Aug 2008
i try put the schem but is like 560K ,and office doc format
  Reply With Quote
Old 29th August 2008, 05:58 AM   #5
diyAudio Member
 
Join Date: Aug 2008
cool like the other ch sink...(advice don't touch the to3 pnp and npn at same time....)
  Reply With Quote
Old 29th August 2008, 06:05 AM   #6
diyAudio Member
 
Join Date: Aug 2008
can i check those whitout the outputs in place? the oscil?( by the way i have an oscilloscope again, that dont have last two times that repare it) advice on those checks...
  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
Yamaha AX-500 clapster Solid State 14 25th July 2010 12:49 AM
modding my Yamaha speakers - need advice zafira1981 Multi-Way 3 2nd June 2009 12:58 AM
yamaha rxv 795 av amp homertooties Solid State 5 11th August 2007 09:37 PM
Yamaha Amp Dynsdale Solid State 5 29th September 2005 07:32 PM
Poster in Musical Instrument forum needs bridging advice on BrianGT 4780 advice moving_electron Chip Amps 0 16th February 2005 12:37 AM


New To Site? Need Help?

All times are GMT. The time now is 04:59 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