Hoffman 610 Lost B+

[Joe Connor]

Ah, yes, steel wool. I learned my lesson back in the late 1950s when I cleaned my Lionel train tracks with steel wool and some of the fibers remained behind. A very interesting light show for a 7-year-old.

[Doug66]

Well after finding a replacement filter cap in the vertical section in which I had pushed it where the leads were touching (why I had no vertical), and another short; I am finally ready to post my 1str results on the screen.

I can't tune the signal in. The tuning slug doesn't get it any plainer than this. Tuner tubes and IF tubes have been subbed with no change. Sound is just a weak buzz.

Video IF voltages check ok.. I'll start checking other voltages next

[Eric H]

The horizontal frequency is off, try turning the slug in the horizontal coil, it should be somewhere near the oscillator tube.

Edit: L111 on the schematic.

[Doug66]

Actually, when I replaced one of the tube sockets, I forgot to put a resistor back. That was my problem. NOW, I have a pretty good pic, BUT no audio al all. The audio section from the 6AL5 forward is working because wiggling that tube produces cackling in the speaker. Voltages check normal on the audio tubes

[Doug66]

I've gotten it t where I have a god pic and weak sound. I don't seem to be getting any gain thru the 1st Sound IF(T100). It's got two internal caps, but the schematic doesn't say what they are. I'm going to try and find a replacement IF. Hoffman 5304. I crossed it to a Miller 6190.

[Doug66]

my IF transformer came in. After much tweeking, I have a good pic, but the audio is still week. With the volume at max, the sound is adequate but not overly loud. When adjusting the tuner slug the seems to be only one brief place where audio comes thru, but the video comes thru at a much wider range. The video doesn't seem to be at it's best where he audio is. It's on the bench and has been playing for over an hour.