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jakdedert jakdedert is offline
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Default Kenwood KA-5700 - Please help me repair / Hobby Repair / BlowsFuses

Bob Urz wrote:


bloggybob wrote:
Tony , look in the circuit corresponding to the output that blew again
and
there are driver transistors in that circuit that drive the bigger power
transistors ... check them for shorted or open or for a bad gate ...
its a
typical output stage and when you lose the main outputs it usually
takes out
the pre-drivers with it , not always but sometimes ... i would almost bet
you that one of your pre-drivers is shorted ..... always compare one
channel
to the other with a meter at different points , i usually meter all
drivers
transistors as its a good sign when all the drivers are reading good ,
then
i proceed to the final output stage then i will meter and compare the
final
stages against each other before i fire it back up ..... hope this helps


regards


If that's the antique i think it is, good luck getting the output
transistors. They were something like B688's or such with mount tabs
on the sides. If your clever, you can retrofit others in but its hardly
worth the hassle.

Bob


It is an antique; but I believe he said he'd replaced the out's once
already....

jak


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