TOS troubleshooting questions
2011-02-18 by gnw
I'm trying to troubleshoot my Arp Quartet, which I powered on recently only to find that it's LED's light up but it doesn't make a sound. I've checked the power supply voltages and all appear to be in spec. Based on what I've read, I'm naturally suspicious of a faulty M50242 TOS chip, but I'm not really clear on how to go about testing and troubleshooting it. I've tried to scope what I believe is the clock in (pin 2), as well as the divided outputs, but I'm not seeing much of anything. Also, I am seeing 12 VDC at pins 1, 3, 4, 5, 6, 7, 8, 11, 12, and 15, which doesn't seem correct (pin 1 is supposed to be +Vcc). If anyone could steer me in the right direction here, it would be much appreciated. -George