Got flyback in,no picture

I got the flyback changed on the Philco today. I tried it out with a vcr. at first the tubes would all glow but I noticed the damper tubr got real red and smoke came out from under it and the breaker would trip. A little part that looks like a resistor with wire wound over it was getting red hot. I went ahead and clipped it and turned it back on. The damper tube looked normal after that and the breaker quit tripping. The neck of the crt glows and all tubes glow but the screen is blank. Also I heard a little bit of sound at the beginning but it quit and now all I get is some static when I turn the volume control. Could that little resistor be the reason for no picture? Would the flyback burning out cause the resistor to go bad? I am not the most knowledgable when it comes to these. Does anyone have any advice?
John

[jroberts500]

Hi,
I recommend you write back and tell us something about yourself and anything else you could share. Next, I would post photos of your set inside and out. Then, I would find a schematic and an ohmeter. People will respond. You will figure out the rest.

Hi. My name is John Nicolas. I live in Liberal Mo. in the SW part of the state near Joplin and the Kansas border. I work for Wal Mart. I also fix appliances. Iam interested in old cars,model trains old electronics and about anything old. I just recently started picking up some old tvs to work on. I still have a long way to go in understanding how they work and how to troubleshoot them. Here are a couple of pics of the set I have been asking advice on. The tube looks real bad but I plan to fix that if I can get it working.
John.

[bgadow]

Welcome, John! It is helpful to know a person's background. I know there have been times when I've offered advice to folks on here, and I thought they were a complete novice. Then I found out they could build a tv with one hand tied behind their back!

Did the tv repairman have any Sams photofacts? There seem to be plenty of copies of them for those years. If you needed them I'm sure someone on here could help you out. I've got a lot of them but would have to mail you a copy. I do think the schematics would be a real help with this. I'm not quite smart enough to tell you what the answer to your problem is. I wouldn't worry so much about the sound quite yet. First you need to find out if the flyback is correct & hooked up right. If there are some differences in the two I could see where that could cause real problems. I don't think the resistor is the cause of the problem, more an effect of the problem. Too much juice going through there, but why?

Are you familiar with removing cataracts from these crts? I'm sure if you've looked around the old threads you are. This would probably be an easy one to do, as bad as it is. Find out if its electrically good before going through the trouble.

I think this is going to be a neat set when finished. Have faith-I've seen a lot worse! HV problems of this sort are not my strong suit, and years ago I threw sets away rather than tackle them. This one should be saved, though. Good luck! You found the right place.

[Eric H]

Originally Posted by jroberts500

Hi,
I recommend you write back and tell us something about yourself and anything else you could share. Next, I would post photos of your set inside and out. Then, I would find a schematic and an ohmeter. People will respond. You will figure out the rest.

Actually he did post here: http://audiokarma.org/forums/showthread.php?t=60874

John, it might be best if you kept all your posts on this set in one thread, it's easier to keep track of it that way.

[Bill R]

Clipping out parts may not be the best way to troubleshoot a problem. You need to first verify that the flyback is installed correctly and that it is the same part number or one that is an acceptable substitute. Then you need to determine what is causing the damper tube to draw excessive current. Just because a tube looks normal it may not be working. If the part you clipped went to the plate of the damper pin 4,10 or to the cathode pin 7 ( the only two connections by the way other than a 22mfd cap connected to pin 4,10 which might be bad) the tube would still light up but it would not be doing anything. Schematic will be esential here. It is sams 1119-sed.

BIll R

[jroberts500]

Nice set! Definately worth the trouble!

[Chad Hauris]

make sure there is negative bias voltage of the proper amount at the Horiz output grid. (like about -50 volts (negative) If the HO tube has no bias (on account of no drive signal) the tube can draw 1.5 amps or so and, because the HO tube draws its supply voltage through the damper, this can overload the damper.

Be careful because you can destroy an HO tube through an overload and the damage may not be apparent by looking at it. Had this happen on a CTC-16...had bad connection for plate voltage to the horiz oscillator. HO tube lost bias and overloaded. Even when I fixed the osc. to get drive back, the HO tube was toast. Put in new HO tube and worked like it should.


Also I have put a fuse in HO tube cathode circuits...3/10ths of an amp. It will blow if there is an overload and save your flyback.

I connected the flyback exactly the way it is in the set. The parts chassis other than a few minor differences is the same as this one. The flyback looks exactly the same as the bad one. I will check with the guy and see if he has any service information on these sets. The next thing is to find a resistor to replace the one that burned out. I wonder if a new one would burn out too. The guy said he had some flybacks so I may get an nos one from him and try it if this doesnt work. It is a neat set. The vhf and uhf tuner knobs and dials are together on the same shaft. It is lighted also. The back of the set is metal too.
John

[southernguy]

Hi John, your Philco looks very simmular to a 23 inch Philco consol that I have. Mine has a AH62737 chassis (backwards from yours) with a 25XP22 CRT in it. Funny though, it sounds like your set has the same problem as mine did at one time, might not be the case though. The set had a cracked H output tube when I got it. At the time I thought well I'll just pop in a new one. So I did, and the set came right on and played for about 10 mins and then all at once the picture went dark and I herd the sound glass crackling. There went another Output tube and a nasty smell comming from the flyback cage. Problem ended up being the Damper tube. I ended up changing the Damper witch in mine was a 6CG3, HO (6KD6) , and the HV Rect (3AT2).
Its 9 years later and the set still plays very well. Don't give up, Hope you get it to working. I always thought the green tunning eye was neat.
Bruce

I went back to the shop and got a bunch of tv service literature for Philcos. He gave it to me for $2. I found a schematic for my set in one of the books. The part that smoked is actually a damper cathode. What purpose does it serve? Would the flyback going out cause it to fail? I can get several nos flybacks and tuners and other parts from him real cheap. He hasnt used any of it in years and I think he just wants to get rid of it.
John

[southernguy]

Did you just try replacing the damper tube.

[Chad Hauris]

Do you mean the cathode lead actually melted in the damper tube?
You really need to find the source of the trouble by taking measurements, you can't just try this or that without some ideas as to what's going on in the circuit electrically, you will have a difficult if not impossible time fixing the problem by just replacing stuff without finding the fault.
Components that burn up such as resistors or flybacks usually don't doit by themselves, there is an overload or short somewhere in the circuit that causes too much current to be drawn.

This part is under the chassis. It is not part of the tube. It looks like a resistor with wire wound around it. It connects to the #7 terminal of the tube socket.
John.

[Chad Hauris]

It is probably a choke coil, the finer wire on it would burn out under an overload.