kenwood KAC-628 car amp problem
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=39468
Printed Date: May 13, 2024 at 3:27 AM
Topic: kenwood KAC-628 car amp problem
Posted By: wahee
Subject: kenwood KAC-628 car amp problem
Date Posted: September 21, 2004 at 8:13 AM
hi everyone would anyone have a .pdf or scan of the circuit for this amp, or would know the type of zener diodes used in the power supply. any help appreciated
Replies:
Posted By: kgerry
Date Posted: September 21, 2004 at 11:44 AM
post the diode designation... D601, etc. ------------- Kevin Gerry
Certified Electronics Technician
MECP First Class Installer
Owner/Installer
Classic Car Audio
since 1979
Posted By: wahee
Date Posted: September 22, 2004 at 7:57 AM
hi its D7 I think it might be a 7.5v but not sure. The transistor Q17 is getting very hot
Posted By: kgerry
Date Posted: September 22, 2004 at 2:42 PM
yes it is... it's an RD7.5JS Zener you've probably got a bum power FET, replace both Q17 and Q18 as a matched pair
-------------
Kevin Gerry
Certified Electronics Technician
MECP First Class Installer
Owner/Installer
Classic Car Audio
since 1979
Posted By: wahee
Date Posted: September 22, 2004 at 5:28 PM
thanks for that. I have ordered a pair of Toshiba equivilents which should hopefully do the trick.
Posted By: heavilymedicate
Date Posted: September 22, 2004 at 6:10 PM
You guys are more educated then I. Some day, I hope to be as smart as the two of you. I sh*t you not.
Posted By: stevdart
Date Posted: September 22, 2004 at 6:39 PM
I know what you're saying, heavily...I haven't advanced yet to the realm of zener diodes yet either. But I'm getting this stuff a little at a time. I never miss a post that kgerry writes...I put him in a class with professors. Like DYohn and Rob at his Forbidden empire, he is one who provides certain and unquestionable advice (and it's free!).
-------------
Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: kgerry
Date Posted: September 23, 2004 at 4:58 PM
lol where do i mail the cheque??? BTW wahee, the originals are made by International Rectifier and are only about 5 bucks each... why are you subbing in some generic Toshiba part? ------------- Kevin Gerry
Certified Electronics Technician
MECP First Class Installer
Owner/Installer
Classic Car Audio
since 1979
Posted By: wahee
Date Posted: September 23, 2004 at 5:23 PM
hi - I couldnt get the IRf part frpm my supplier - RS components - they had everything but . I actually got some Toshiba 2SK2232 - It was cross referenced for the IRF part. I havnt got around to fitting the parts yet as im fixing a couple of old philips cd104 cd players at the moment, but I should hopefully get the Kenwood amp fixed by Saturday (as long as theres no more hidden gremlins) thanks for all your help
Posted By: wahee
Date Posted: September 24, 2004 at 1:53 PM
hi kgerry, could you tell me if D34 is the same value of diode. I think im gonna have to get the IRF originals as the toshiba are not the same after all
Posted By: kgerry
Date Posted: September 24, 2004 at 2:21 PM
D34 is an RD16JS 16 volt Zener i always recommend using originals.... i never scab in ECG/NTE semis or sub parts to something else unless absolutely neccessary... those IRF's are very common ------------- Kevin Gerry
Certified Electronics Technician
MECP First Class Installer
Owner/Installer
Classic Car Audio
since 1979
Posted By: wahee
Date Posted: September 25, 2004 at 4:14 AM
thanks again for your help. I have ordered a pair of IRF's and have taken your advice on subbing parts 
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