Hi guys, i have a 1986 Fisher PC420 television. Chassis #A7R-42000
it works but has no picture width and some barrel distortion. i narrowed it down to low B+ 89volts. service manual says it should be 111volts.
it uses these Sanyo hybrid IC chips for error detection and drive that are discontinued and i cannot find anywhere. i found one post regarding a Sanyo TV with same symptoms and the resolution was the error detect module.
Part # JU0161 and JU0148
i'm now looking at bypassing that error detect to the optocoupler circuit somehow with my own. i don't have the skills to design a circuit and don't know where to start.
at 89VDC the optocoupler diode measured from pin 1 and 2 is 0.963 volts
i'll attach pics of the IC's and schematics. any help is appreciated.
thanks
it works but has no picture width and some barrel distortion. i narrowed it down to low B+ 89volts. service manual says it should be 111volts.
it uses these Sanyo hybrid IC chips for error detection and drive that are discontinued and i cannot find anywhere. i found one post regarding a Sanyo TV with same symptoms and the resolution was the error detect module.
Part # JU0161 and JU0148
i'm now looking at bypassing that error detect to the optocoupler circuit somehow with my own. i don't have the skills to design a circuit and don't know where to start.
at 89VDC the optocoupler diode measured from pin 1 and 2 is 0.963 volts
i'll attach pics of the IC's and schematics. any help is appreciated.
thanks
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