'76 9" Toshiba blackstripe color TV

[radiotvnut]

I dug out this one and decided to play with it. Currently, the picture is dim with lots of bleeding and smearing. If I advance the brightness too high, the picture becomes washed out. Checking the collectors of the 3 video output transistors reveals only 46 volts (no matter if the CRT is connected or not). The B+ that feeds the video output circuit is around 124 volts; and, I think this voltage should be at least 100 volts higher. It was getting late and I didn't have time to check anything else; but, I suspect a bad cap in the B+ line to the video output stages. I've seen it happen a lot in later sets. I suspect this one will have a very sharp picture once I get it working right.

[miniman82]

By 'washed out' do you mean blooming? Could by the HV supply to the CRT sagging.

[sampson159]

good playing sets with fine crts.dave had one like that in the shop and it had a bleeding ,smearing issue.he changed cap in b+ line and it looked good for about a minute.then it began to hum and,BOOM!like a shotgun blast.set became parts at that point.thank god we were standing in front of it.that cap blew like tnt.i saw him/her a couple years ago and we laughed about it.those are really fine playing sets.

[radiotvnut]

I found the problem, an open 160K resistor in the boost circuit that feeds B+ to the screen controls. Once I replaced that part, I discovered that someone had turned the sub bright control all the way up. Once I reset everything, the TV has a good picture.

[Sandy G]

Looks like a double-1st cousin to the little Sears 9" color set I got offa You-Know-Where for about $12 several years back...Wasn't expecting much from it, but, boy, what a picture ! Mine has a more rounded, "Toadstoolish" plastic case, tho.

[radiotvnut]

I dug out this set and remembered that I forgot to show it in operation. And, I also discovered that this set has "instant on" (CRT filament stays lit as long as the set is plugged in). I was a little shocked to see this feature on a TV from '76. I thought that everyone stopped using "instant on" somewhere around '74-'75. If this were a set that I was using everyday, I'd disable the instant on feature in order to save the CRT.

[zenith2134]

Awesome!! I love these old Toshibas.

Here's my '76 Toshiba 'TV-2' (badged as a XAM) with metal cab & Blackstripe 13" CRT:

[radiotvnut]

Very nice! I recently fixed a similar set, for an older man, that was a rebadged Sears. It only needed a tuner and control cleaning.

[electroking]

Had one of those 9-inch Toshibas, but the screen went a uniform shade of
blue. Service tech told me it was a catastrophic CRT failure, so the set did not
get out of the shop alive.

Regarding the instant-on feature, we once had a 1975 Toshiba (15-inch or so)
that had the 'Econowatt' capability, allowing you to turn off the CRT heater by
rotating the volume control CCW. A 1977 set (still in service!) also has the
same feature. I guess this was left out in this small 1976 model to save on
the power switch size.