[ct92404]

I realized I made a mistake earlier, I think I said the tape recorder takes 4 AA batteries, but it's actually 6. So yeah, it would be 9 volts. Well, I'm using Ni-Mh rechargeable batteries, which have slightly lower voltage. So the total actually measured at about 7.66 volts.

I found out a couple of things. The volume knob apparently also controls the level in record mode. I turned up the dial a little and tried recording again, and it sounded much louder and clearer. But it still won't erase previous recordings on the tape and there are overlapping sounds. I found where the heads connect to the circuit board. I measured the voltage at the wires that go to the erase head with a meter and I got about 7.4 volts. There is voltage present and so the head should be working. But it's not erasing for some reason. On a hunch, I measured the resistance across the wires going to the erase head and I got nothing, on all the meter settings. It's like the circuit to the erase head is open. So it seems like the problem is not with the circuit, but the erase head itself. Either a connection has come loose going to the head (hopefully! that's easy to fix) or the head itself is bad.

I'm going to see if I can get better access to the erase head and check if maybe a wire has come loose or unsoldered somewhere. I hope it's not the head itself. Do erase heads fail? I mean, it's basically just a small electromagnet, right? There shouldn't be much to go wrong with it. I'm still learning about tape recorders though. I used cassette tape recorders a lot when I was a kid (not reel-to-reel like this, that was before my time). But I never really knew that much about how they actually worked at the circuit level.