I received a korg poly 800 and happy to get it back working. I am unable to power it on via the cord or battery. I did find the schematic and just started to look at it. I am needing help on getting it back to life.
I did check the voltage on the jack and have 11.7 volts. I then went and checked the diode - d2 - as it had 11.7 volts coming out. I did unplug the unit and check the diode with continuity check and it looked good - infinite one direction and 576 in another. They were not the same so i went on to troubleshooting. I have limited skills on what to check but if you give me directions i can do whatever. I then looked at q1. I used the ground with the resistor and then measure the pins. I have 11.7 on one pin , 11.7 on the other pin , and then no volts. I thought that was odd.
I am not sure what to check next . I do not know how to check if the transistor is good or not. Any help would be appreciated. I hate to throw this away.
Also i noticed d1 was hooked to two double A batteries. I measured and got 3.17 volts. i thought it was odd there was not a diode present.