Hello, Happy new year to everybody !
Since months, I didn't posted about this (quite) old InterM PC1635's repair.
I have good news : it's fully functionnal now !
Let me resume it to you : in the left board, it was impossible to measure a bias voltage on the power transistor's bases. I was loosing my mind, because every transistor and component tested were good. The pcb had been inspected with a magnifier lens, and no problem were detected. Transistors replacement didn't gave any improvement.
So, I decided to verify the connections beetween the driver transistor emitter Q211and the power transistor's bases : no continuity through the pcb trace !
Jesus ! Here was the problem ! There was a tiny crack on this trace, only visible with a microscope !
Everything came back to life after the pcb fix... Another salvaged boat anchor !
Thanks for all the help
Since months, I didn't posted about this (quite) old InterM PC1635's repair.
I have good news : it's fully functionnal now !
Let me resume it to you : in the left board, it was impossible to measure a bias voltage on the power transistor's bases. I was loosing my mind, because every transistor and component tested were good. The pcb had been inspected with a magnifier lens, and no problem were detected. Transistors replacement didn't gave any improvement.
So, I decided to verify the connections beetween the driver transistor emitter Q211and the power transistor's bases : no continuity through the pcb trace !
Jesus ! Here was the problem ! There was a tiny crack on this trace, only visible with a microscope !
Everything came back to life after the pcb fix... Another salvaged boat anchor !
Thanks for all the help
well done.- Status
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