Motorola VT71 - Videokarma.org TV - Video

Sting · #1 06-09-2011, 02:01 AM

I found a Motorola VT71 7" in my parents garage that I would like to restore, My dad said he doesn't even remember where it came from, or who owned it.
When I found it, the cord cut and speaker removed. I made a cord and plugged it up but nothing happened, all the tubes did glow and the picture tube was also glowing but no picture. Is there a chance that the tube might need replacing or could it be something simple...would like to see if it would work before I just start replacing capacitors.

Zenith26kc20 · #2 06-09-2011, 09:22 AM

On those Motorola's the caps are the biggest problem. I have recapped a couple and they worked fine. They are good sets to repair. Also, the selenium rectifiers (finned squares underneath) are probably bad. If they "pop" you are in for an unpleasant(!) smell that lingers a looooong time in the repair area. Also, the high value resistors in the sweep circuits need to be checked. I replace them with one watt and it seems to help stabilize the circuitry a bit. Take your time and recap it and it should be a good start. They are fun sets

miniman82 · #3 06-09-2011, 10:09 AM

It will need complete recapping, especially those 6kv ones for the sweep.

Phil Nelson · #4 06-09-2011, 12:42 PM

Here is an article about restoring that model.

http://antiqueradio.org/motvt73.htm

There really is no point in trying to play it now to see if it would work. You need to replace at least the electrolytic capacitors and the high voltage capacitors. At that stage, you could power it up to see if anything happens, but I still would not expect much until it is completely recapped.

Here is an article with information about replacing capacitors, if you need it:

http://antiqueradio.org/recap.htm

They are neat little TVs. There is a chance that it needs a new tube or has some other simple problem, but it's not practical to try to find that out until you get all those rotten old caps out of the way.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Electronic M · #5 06-10-2011, 03:35 AM

The video detector diode is going bad in mine, and I've heard that it has happened to other VT-71s so I would reccomend you replace yours(might even get video after you replace it).

Tom C.