Plate Amp power cutout - 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 9th March 2007, 04:33 PM   #1
3KFX is offline 3KFX  United States
diyAudio Member
 
Join Date: Dec 2005
Location: Buffalo Center, IA
Default Plate Amp power cutout

We (A friend and I) have a Kenwood Powered Subwoofer plate amp rated at 160 W power draw that goes into protection mode after the gain is set above ~1/4 total gain. Can anybody give us some guidance on how to find where the problem originates and what we could do to fix it?

If more information is needed, I'll try my best to get the info to you.
  Reply With Quote
Old 9th March 2007, 06:02 PM   #2
diyAudio Member
 
XEAGLEKEEPER's Avatar
 
Join Date: Jan 2006
Location: central Iowa
3KFX
Hello neighbor.Do you have a schematic or service manual?Have you replaced any parts(substituded) in the amp?
Dave
__________________
Ret. USAF... AKA- Avionic *** Solder slinger for hire...***
  Reply With Quote
Old 9th March 2007, 07:46 PM   #3
diyAudio Member
 
Join Date: Jun 2006
Hello, I am the friend that 3kfx talked about up there. None of the parts have been replaced in the plate amp. We suspect that the output transistors may have issues because there is a possibly that the outputs to the speaker(+ and -) touched. I will try to post a picture soon.
  Reply With Quote
Old 9th March 2007, 08:00 PM   #4
diyAudio Member
 
XEAGLEKEEPER's Avatar
 
Join Date: Jan 2006
Location: central Iowa
If the + and - touched,chances are the outputs are toast..
__________________
Ret. USAF... AKA- Avionic *** Solder slinger for hire...***
  Reply With Quote
Old 9th March 2007, 09:08 PM   #5
3KFX is offline 3KFX  United States
diyAudio Member
 
Join Date: Dec 2005
Location: Buffalo Center, IA
would it be just the transisters... or could it be more?
  Reply With Quote
Old 9th March 2007, 09:40 PM   #6
diyAudio Member
 
XEAGLEKEEPER's Avatar
 
Join Date: Jan 2006
Location: central Iowa
Hard to tell without a schematic--possibly emitter resistors also The resistors would be the larger 1,2 or 5 watt wirewound low resistance variety.They are probably located close to the output transistors. Did it blow any fuses?
Dave
__________________
Ret. USAF... AKA- Avionic *** Solder slinger for hire...***
  Reply With Quote
Old 10th March 2007, 07:00 AM   #7
diyAudio Member
 
Join Date: Jun 2006
We carefully looked at all the components, 3kfx and I, and also we had another person, who has previously built simple amps and knows a decent amout about amps take a look at the components and couldn't find anything visibly burned. The resistors all looked fine. There was a tiny bulge on one of the two bigger caps. I'm not sure what that means, but he said it wasn't anything to worry about. Also, on a side note, the outputs consist of two orange (positive) wires coming from the board, and one black one. Its not related to the problem, but why the doubling up of the positive leads at the same gauge?
  Reply With Quote
Old 10th March 2007, 08:45 AM   #8
diyAudio Member
 
XEAGLEKEEPER's Avatar
 
Join Date: Jan 2006
Location: central Iowa
When I stated outputs I was referring to the output transistors. The wires you were referring to are probably the AC wires off of the transformer. As for the resistors and output transistors they are going to have to be checked with a DMM digital multimeter.They may look OK but still be bad they need to be ohmed out(checked)
The bulge on the capacitor is not good . This is another issue that needs to be addressed.
__________________
Ret. USAF... AKA- Avionic *** Solder slinger for hire...***
  Reply With Quote
Old 10th March 2007, 08:57 AM   #9
diyAudio Member
 
XEAGLEKEEPER's Avatar
 
Join Date: Jan 2006
Location: central Iowa
Just curious.Do either of you have a DMM? Do you know how to check a transistor or resistor?Can you post a couple close-up pictures or a schematic diagram of the amp?

Dave
__________________
Ret. USAF... AKA- Avionic *** Solder slinger for hire...***
  Reply With Quote
Old 10th March 2007, 05:25 PM   #10
diyAudio Member
 
Join Date: Nov 2005
Sorry guys for the confusing posts, but I was logged in on an old account (3KFX - I was at school and didn't remember my user name or password, but apparently guessed the old account)... I'll be using this one from now on...

I have access to a digital multimeter, and some other basic electronics tools. A resistor I assume you check by making sure it's the stated resistance. A transistor, I don't know how to check (though I haven't had time to search Google yet). Also, if the capacitor should be of concern, how would I check that.

Does anybody have a normal testing procedure they go through? Do we first test what voltage is put out by the amp before it cuts out? Check the transistors? resistors? capacitors? What should we be looking for?
  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
two BIB questions re inner baffle and driver cutout drec Full Range 3 23rd December 2006 03:59 AM
Lenco plinth cutout plans? fishwinker Analogue Source 5 3rd September 2006 03:11 PM
Power supply cutout argonrepublic Everything Else 0 15th March 2006 07:09 PM
Acoustic damping by cutout wood Kjetil Multi-Way 4 31st March 2004 03:06 AM


New To Site? Need Help?

All times are GMT. The time now is 07:44 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