texasmame
Well-known member
I had no pic but chatter. Then. . .
Something went haywire while testing, taking out the 7406 (blew the top right off it) on the chassis. Socketed and replaced but now I get no pic AND no chatter; before I did have chatter but no pic. This is with two different boardsets, one known good and both do the LED on then off when booted.
Replaced the four 47ohm resistors as two of them were pretty crispy. Reflowed EVERYTHING on the chassis and replaced the four heat sink transistors.
All I get now is a dot in the upper right corner of the screen. I can adjust the intensity of it with the brightness control, so guess I at least have HV.
The three voltages are correct from those three voltage regulators on the chassis (5, 15, -15).
So, besides the 7406, what else was probably destroyed with the surge (no visible indicators of any other problems).
Lastly, breaker 2 trips after about 30 seconds, followed almost immediately by breaker 1.
Something went haywire while testing, taking out the 7406 (blew the top right off it) on the chassis. Socketed and replaced but now I get no pic AND no chatter; before I did have chatter but no pic. This is with two different boardsets, one known good and both do the LED on then off when booted.
Replaced the four 47ohm resistors as two of them were pretty crispy. Reflowed EVERYTHING on the chassis and replaced the four heat sink transistors.
All I get now is a dot in the upper right corner of the screen. I can adjust the intensity of it with the brightness control, so guess I at least have HV.
The three voltages are correct from those three voltage regulators on the chassis (5, 15, -15).
So, besides the 7406, what else was probably destroyed with the surge (no visible indicators of any other problems).
Lastly, breaker 2 trips after about 30 seconds, followed almost immediately by breaker 1.
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