My Predicta died today
 

I was watching a DVD on my Predicta and then suddenly the image collapsed into some sort of vertical line and then the screen went dark. Now it turns on, there's audio but the screen doesn't light up. Any ideas on what can be wrong with it???

How fast did the image collapse? Did it go from full screen to a vertical line instantly, or did it take a few moment for the image to slowly shrink to the line and then fade?

It was very fast: in one moment the screen was full, and then in a second it collapsed into the vertical line.

Predictas never die.... as long as screwdrivers exist... :D

SR

Tough call, but I'd suspect a bad solder joint on the board around the horizontal output first. Second I would suspect an open winding on the flyback, and third a bad connection to/open winding on the deflection yoke.

Try letting it cool down for a 1/2 hour and then see if it comes back to life. If not, wiggle the 6DQ6 horizontal output tube in its socket lightly while it's on to see if high voltage comes back. If not, check the plate of the horizontal output and see if it's glowing cherry red... if so, this means the horizontal oscillator is dead. Otherwise you'll have to check the resistance and continuity through the flyback and yoke.

Could also be a simple power supply issue, without a print in front of me I can't help to pinpoint that though.

Pull the cap off of the horizontal and check it for B+. If that is present I would check voltages around the vertical output tube (plate). If no B+ on the HOT, look around the damper tube for proper voltages. Don't go poking around with the cap on the HOT if you are using a DMM. The high voltage pulses will kill your meter.
Most Predictas I have worked on develop vertical trouble more than anything else.

what about checking the tubes ?

mike

My father fiddled with the linearity and width controls on the back and the image reappeared. Is this normal?

the pots on those sets are not the best and can cause issues.

Not to be flippant or anything, but quite often with troubleshooting it is the most simple and obvious things that often get looked over. A good example of this comes to mind in a situation that I recently and unfortunately experienced. I work as an electronics technician (maintenance) in a manufacturing facility (factory). LOL! At any rate, there was a rather complicated part of our process that developed erratic/intermittent problems.

Well, after the supposed best of the best in our crew took pot shot guesses and a number of "cold boots" the German company flew over an engineer with a laptop to hopefully fix what everyone had determined must be a software issue. As it turns out there were several 3 phase contactors that had intermittently high resistance contacts. This was most likely due to exposure to dirt and chemical residue over time as the electrical enclosure had no positive air pressure to keep such things out as do all of the others (most are air conditioned in a separate room).

Point being that in this case a lot of money was spent and production time lost because of the most rudimentary problem that we could have had and the first thing that we should have gone over with a fine toothed comb. In my defense I will add that I asked about checking the array of electromechanical contactors and was told that they had all been checked. I still checked one and showed the boss the strange readings, so he let me change that single one, but seemed resistant to letting me go further. Sometimes too many minds involved (and bosses looking to impress their bosses by being the one who saved the day) can really hinder the troubleshooting process. Just sayin'

I see many threads complaining of sudden death and crackles that would make me wiggle tubes and controls to find the intermittent. Ditto on checking the easiest tests first. Think of all the tube socket terminals and control points in sets, sometimes dozens, all subject to oxidation.

Looks like it's dirty pots, similar to what Dave mentioned. The wiper inside losing contact with the carbon track inside the pot. Some contact cleaner may help, or new pots. Either option should fix the TV set.

Now it is really dead
 

I was watching and then the image collapsed again, but this time there was lightning inside the TV and smoke appeared coming from ( it looked like ) the flyback area. Now I am really in trouble. It will be hell to find someone in my area willing to repair this thing... and if the flyback is no good anymore, most likely I will not be able to find a good one.

The Flyback is inside a metal box so if it arced you wouldn't see it.
Possibly a cap shorted and took out a resistor.

The first part may be correct as there are no television repair shops left, or not many. But if the fly is bad, I would say that you have a better chance at finding one for a Predicta than most other sets of that era. I say this because while other trends have come and gone in vintage electronics, the Predicta for whatever reason has long been sought after, so there are many around and I would imagine a lot of parts. Good luck on this!

Thanks! I talked to an old gentleman who started to repair TVs in the 60's. Although he is almost retiring, he agreed to take a look at the TV to find out what happened. I am still in the dark, but I am taking precautions just in case the flyback is gone: I already started the search for a replacement one; if the one on the TV is no good anymore I will have a replacement, and if it is still good I will have a spare one just in case. In theory it should not be much difficult to find, since there are many Predictas here in Brazil, this TV really sold well here, but one thing I learned over the years is that an specific vintage TV may be easy to find, but specific parts of that vintage TV can be harder to find than the TV itself. Buying another Predicta just to take the flyback is out of question because everybody, everywhere, is asking high prices for that TV. I will have to find a lone flyback, without a TV attached to it.

Good point about the parts being hard to get, even for a popular type. I recently had to part out a beautiful 58 Zenith Space Command. Up to a point I would have never sold a single part from this set. It just seems wrong as a sort of collector of such things to destroy or dismantle something that regardless of popularity frankly is just very old and not easy to find. However, I couldn't sell the set as for the most part people don't want to bother with the cost and risks involved in shipping. So, I was put in the situation with the hope that somebody will want the easier to ship parts. Most particularly the remote control related stuff.

So I guess this works both ways, but I still think that you will be able to find a Predicta fly if needed and it's great that you found an older tech with the knowledge to even begin to work on tube driven equipment. I sometimes wonder what will happen when all of the great (and in my mind superior) understanding of electronics is gone. I hope that somehow it is passed down through younger people interested in the golden age of electronics. I am in my early 40s and grew up in the wake of this era, and luckily enough of the stuff was stored and often used when I began training in high school. Most of our school's donor sets were 50s and 60s models back in the 80s. We even had a Predicta in the lab! Then it was just oddball junk for the most part; the Predicta that is. I'm also glad to have been taught to read an actual VOM scale as all of our meters then were Simpsons. Later in college when digital meters were common I used to love the electronics (digital) wiz kids scratch their head as I did my lab work with one of the last two working Simpson VOMs.

On the few Predictas I have replaced flybacks on, the replacement part consists of only the windings and HV 'tire' with tinned wires sticking out. You have to re-use the powdered iron core, 'C' clamp, and terminal board. AND you have to be super careful to replace the two thin fiber spacers between the core halves, as these determine the resonant point of the transformer.

These were Philco direct replacements, but i've read that the whole transformer could also be obtained from other supplyers (maybe like Triad, Thordarson et al.).

If someone can provide Philco, Thordarson and Merit part #s, I may have it in stock.

I can look them up, but I need to know what model Predicta chassis it is.

I believe my TV ( Brazilian Predictas have a slightly different cabinet; see this photo: http://www.tvhistory.tv/1958-Philco-Predicta-BRAZIL.JPG ) uses the same chassis as this model of American Predicta:

That looks just like the American Holday model which uses the 9L37 chassis.

Philco = 32-8853-1
Thordarson = FLY-196

And... I am very lucky
 

The old gentleman I referred to in a previous post examined the TV today. The problem was something very simple: the wire that connects the flyback with the 6DQ6A tube ( I believe it is that tube ) short circuited and burned. So it was only a simple wire and not the flyback. In a few minutes he solved the problem and the TV is now working again. I am very happy.:banana:

Nice to know!

Lucky you :thmbsp: Those Predicta flybacks can be hard to find and expensive.

This Predicta is not letting me have peace: today it malfunctioned again. I turned it on and immediately heard a small "pop" sound coming from the inside of the set. Them I waited, and waited, and waited... and no sign of life came from the TV, no sound, no light on the screen, nothing. The tubes inside the TV are lighting up, but there's no other signal of life coming from the set. What can be wrong now? The tech that repaired it will only be able to take a look on Sunday.

Fusible resistor popped?

Sand coated fusible resistor was my first thought, but wasn't sure this model uses one. We called 'em "Gravel Gerties".

I have read this whole thread and do not see it mentioned , so ;

Has this TV ever been properly restored/recapped by someone in the know about Predictas ? There are quite a number of things that could go pop and render your TV inoperative in the way you describe . The tube's heaters lighting means the set is getting power and that at least part of the circuits are still functional . With neither picture nor sound a B+ voltage issue is one highly likely possibility especially if any old capacitors are still lurking about in there . If it has been properly restored maybe your just seeing the "infant mortality" of the many new components ? It it hasn't been properly restored , even when this most latest issue is fixed , you'll likely begin frying expensive parts if you keep running it ...

I hope your set is ok!!!!!

The TV was restored by it's previous owner, who is a collector that seems to know a lot about those sets. But the truth is, that he admitted to me that he didn't replaced all of the capacitors of this TV. I remember he saying something like it was a lot of work. So that might be the origin of the problem, right?

Yes, it is a lot of work to properly replace all of the capacitors in Predictas, but if that is not done, the set may not be very reliable. These articles show what I did to restore a couple of different models (one 21-inch, the other 17-inch).

http://antiqueradio.org/philc12.htm

http://antiqueradio.org/PhilcoH3412L...Television.htm

Not knowing exactly what was done, it's hard to say whether the previous owner did a thorough job. Predictas were known for being somewhat unreliable even when fairly new.

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

HI All;
I would say to watch Bob's Videos on when He restored His Predicta's, and then follow or check the one you have and see If what He did has been done to yours.. And also look at Phil's articles mentioned above and doing the samething.. Otherwise it might be easier for you to replace everything, rather than waiting for it to "pop" and then replacing it..
THANK YOU Marty

TV is working again. The tech detected that it was a small diode that had short-circuited. Probably it was fault of the outlet I was plugging the TV in, it doesn't seem to hold the plug very firmly.

Very good,thanx for the good news :)