bhuskins
Super Member
I have a KR-9600 recently acquired that remains in protection upon power up and the relays do not engage. So I've read most of the threads about issues to look for and I'm not finding an obvious repair. Most all of the voltages are within a reasonable tolerance when compared to the schematic EW has posted that shows the power supply boards A and B and the relay board.
All of the Power Supply Board B voltages read properly.
Most of the Power Supply Board A reads properly (exception below)
The relay board shows pin2 less than 50mv and pin 7 at -8.2v which appear to be correct.
On Power Supply Board A all of the voltages around QK2, QK3, QK5, QK6 are correct as well as most of the pins that have a listed voltage which are pins 23, 15, 28, 33, 6/14, 17, 18, 19, 21, 7/22, 3, 9, 11 and 1
Pins with issues are
pin 30 reads fluctuating between 57v~59v (should read 67v)
pin 25 reads fluctuating between 57v~59v (should read 67v)
pin 10 reads -30.5v (should read -35v)
When reading voltages around QK7
C reads 13v (should read 0v)
B reads 36v
E reads .148v (should read .15v so that's ok)
Also both sides of Rk29 (1M resistor) reads 36v and the anode of Dk6 diode reads 13v and the cathode reads 36v. Also the side of Rk22 (220K resistor) that’s supposed to read 12v reads 36v and the other side reads 13v and should read 0v. I haven't measured the other 6 transistors on the board yet because of the issues discovered above. Rk22, Rk25 and Rk29 don't read correctly in circuit but I haven't removed them yet to confirm they are good or not. They look perfectly fine but looks can be deceiving I guess. Finally, diodes Dk6 and Dk7 test fine in circuit with a diode check.
Any ideas on what needs replacing? Maybe EW can chime in?
All of the Power Supply Board B voltages read properly.
Most of the Power Supply Board A reads properly (exception below)
The relay board shows pin2 less than 50mv and pin 7 at -8.2v which appear to be correct.
On Power Supply Board A all of the voltages around QK2, QK3, QK5, QK6 are correct as well as most of the pins that have a listed voltage which are pins 23, 15, 28, 33, 6/14, 17, 18, 19, 21, 7/22, 3, 9, 11 and 1
Pins with issues are
pin 30 reads fluctuating between 57v~59v (should read 67v)
pin 25 reads fluctuating between 57v~59v (should read 67v)
pin 10 reads -30.5v (should read -35v)
When reading voltages around QK7
C reads 13v (should read 0v)
B reads 36v
E reads .148v (should read .15v so that's ok)
Also both sides of Rk29 (1M resistor) reads 36v and the anode of Dk6 diode reads 13v and the cathode reads 36v. Also the side of Rk22 (220K resistor) that’s supposed to read 12v reads 36v and the other side reads 13v and should read 0v. I haven't measured the other 6 transistors on the board yet because of the issues discovered above. Rk22, Rk25 and Rk29 don't read correctly in circuit but I haven't removed them yet to confirm they are good or not. They look perfectly fine but looks can be deceiving I guess. Finally, diodes Dk6 and Dk7 test fine in circuit with a diode check.
Any ideas on what needs replacing? Maybe EW can chime in?