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Recapped Technics SE-A70 new issues now!
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Author:  banebadboo [ 01 Feb 2020, 09:51 ]
Post subject:  Recapped Technics SE-A70 new issues now!

Hello all,

So finished recapping my SE-A70 and as soon as I powered it on both fuses blew.(used a DBT after that to prevent more damage) It was working prior to the recap just not well. After rechecking all my work I found that I was missing an insulator pad for one of the power amp transistors. Once it was install no more fuses issues everything powers on correctly and seems to work. I rechecked all the caps and found no bridging or incorrect polarity.

So now my new issue... when I connected the speakers I got a loud buzz through both speakers with the volume off. All the indicator light are good the meters don't move due to the buzz. I turned off the speaker selector and the buzzing stopped. I tried music with the speakers off and the meters seem to move normally and if a select the main speakers the buzz is there and you can hear music mixed in with it. I was told be someone that "Sounds like DC present at the output - I would check for blown outputs now." Ended up replacing
all the power transistors, the speaker relays, I also found a bad thermistor and a resistor that was burned out. Replaced those and re rechecked all the caps, wires and found no bridging. Hook up the DBT and turned on the amp and DBT light went bright and the resistor I replaced burned out again. I need help figuring this out... the resistor is R364 on the diagram its a Panasonic ERD25FJ271.

Any thoughts on what to do next?

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