I brought home this 12" GE B/W from my in laws basement a couple months back. It has no raster. HV is 12kV, cathode is 60V, 1st grid is 25V, 2nd grid is 160V. Filament is 7V AC. It is a XB chassis, from about '78. The only image occurs briefly after cutting power, when the deflection collapses. I disabled the vertical sweep, and the resulting horiz. line is dim. My thought here was if it was some sort of tube cutoff issue, the screen would remain black, but with low emission, a would see the line. I normally wouldn't mess with something like this, but it has become something of a challenge. From what I hear, they used this set for 30 years as a daily watcher in the kitchen. I'm beginning to think it has a bad pix tube, but I don't have pix tube tester to confirm it.

Bad CRT would be my first guess and I've seen these sets (as well as other brands) with CRT's that were so weak that they wouldn't make a picture. Some of them will bounce back with a rejuvenator and some won't. At any rate, I wouldn't junk it, especially if the cabinet still looks nice. If you do some looking, you'll find a tube for that set. Those XB chassis solid state B&W sets were good performers and ran circles around the cheaper tube type GE B&W's of the same time period.

Sounds like a bad tube, same exact thing happened to my brother a little bit ago. Picture just went out all of the sudden, even though all voltages checked out perfect.

RE: GE CRT. Tap gently on the crt neck. Possible open control grid. Screen should flash brightly while doing this.

I've got a little SS GE like this. Dim raster. I can tap the neck with a pencil and it will sometimes flash and run for awhile at good brightness for several hours. Other times, it won't.

If I am destined to find a CRT for this set, it will happen. If not, its sitting by my mom's washing machine where she plays it so she can listen to her shows while she washes. She doesent want a replacement TV. I've tried.

Does the XB chassis have a horizontal oscillator coil mounted on the board?

If it has the horizontal hold coil cranked too far out, you'll get a dim raster too. We used to see those come in occasionally with no pix where some kid had turned the horizontal oscillator coil slug clean out of the coil. Simply adjusting the horizontal frequency brought back a bright clear pix.

Seems to me they were GE sets, but I also recall some Admiral B/W sets having the same problems.....

Cheers,

It definitely looks like a bad pix tube. I've tried cooking the filament at about 11V for 4 hours. I get a dim picture at this voltage, but it goes right back to dark after reducing the filament voltage. I'm leaning towards junking this set, but still on the fence. I used to have a perfectly working 18" XA chassis set, which I gave to something like a Salvation Army store when all I wanted to fix were color sets, preferrably with remote and A/V inputs. Now all I want is the vintage stuff.