Data East Solved Secret Service (Data East, 1988) : Need Help

[jimmywlby]

I need someone's help... I'm new to the hobby and just purchased a non-working 1988 Data East Secret Service pin to restore. On power up, general illumination lights only. On the MPU board, no LEDs light up to indicate PIA or +5 volts. Also, no voltage at the +5 test point.

On the power supply board, .1 volts at TP1 (+5), 12 volts at TP3 and -12 volts at TP4. The voltage coming into the board at CN1 is:
pin 1: 19.8 volts
pin 2: 27.5 volts
pin 3: 27.5 volts
pin 4: 0 volts
pin 9: 0 volts
pin 10: 9.2 volts AC
pin 11: 9.2 volts AC
pin:12: 0 volts

Any thoughts on what the problem is? I'm not sure what I should check next.

Thanks!!

 

[inkochnito]

Take the power board out of the machine and check the back side.
Look for bad solder joints at the connector pins.
Check the fuses.

pin1: 19.8 volts = good (feature lamps working).
pin2 & pin3: 27 volts = good (solenoids working).
pin4: 0 volts = bad (no display power, should be 90VAC).
pin9 & pin12: 0 volts = good (ground).
pin10 & pin11: 9.2 volts = good (supply for -12, +12 and +5 volts).

Check D2, D3 and TR5.
If these are good, IC 1 must be bad.

Good luck,
Peter

 

[jimmywlby]

Thanks, Peter.

Ended up replacing the power supply board and it did the trick. I got the machine to boot up.

 

[inkochnito]

Yeah, that's the shotgun way of fixing things