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Hartke A35 Repair problems

Started by Jesse, March 07, 2024, 10:38:03 AM

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Jesse

Greetings, I have been attempting to repair a Hartke A35 amplifier.
I am using a Variac, and an 8ohm Dummy Load during testing.
When I received the amp, Q8 and R51 were clearly damaged. I have replaced Q7, Q8, Q9, R50, R51, D13 & D14.
After replacing these parts I slowly powered it up again, this time causing Q4 to fail (a short from Emitter to Collector), and R97 is starting to burn up.
I then replaced Q2, Q3, Q4, Q5, Q6, as well as C23, C61, & C64, (R42 measures ok).
Something is still drawing too much current through R97 and causing it to overheat. (R98 seems ok)
With R97 lifted I have + 33 & - 33 volts on the V+ & V-
Does anyone have any ideas of what else to check, or what could be wrong?
Thank you for any assistance!

     -Jesse

g1

schematic attached.
Disconnect your load.  Check for DC voltage at the output.  Do not connect a load until you get the amp to the point where there is no longer any DC at the output.