Old Muntz TV for sale Locally to me, Should I pick it up?

[Electronic M]

Originally Posted by vortalexfan

OK, so a little update, I replaced EVERY capacitor there was to replace in this TV and the TV is still drawing way too much current somewhere because the wattage draw on the TV powering it up was approaching 400 watts and the rectifier tube was still arcing.

Any ideas of where else I could look?

I know its not the power transformer or the choke as I tested those without the tubes in and the current draw was normal.

Could it be my flyback or something in my high voltage section, if so how do I check?

Unlikely, but pulling the horizontal output tube would be a good way to check....your power consumption should drop well below the rating with the H out pulled.

You probably have a short somewhere down stream of the choke.... such as in the focus coil circuit or one of the loads on the B+ lines.

You only followed a fraction of the short tracing procedure I laid out on a previous page of this thread...you should be better served following that method to the end/extending it to the loads on the line than grabbing chit outa a hat and throwing it at a wall in hopes of something sticking...

[vortalexfan]

Originally Posted by Electronic M

Unlikely, but pulling the horizontal output tube would be a good way to check....your power consumption should drop well below the rating with the H out pulled.

You probably have a short somewhere down stream of the choke.... such as in the focus coil circuit or one of the loads on the B+ lines.

You only followed a fraction of the short tracing procedure I laid out on a previous page of this thread...you should be better served following that method to the end/extending it to the loads on the line than grabbing chit outa a hat and throwing it at a wall in hopes of something sticking...

Actually I figured out what the problem was, I had the filter choke wired up wrong, and fixed it, now the low-voltage issue is fixed, but now there's something going on with the tuner as there is some smoke coming out of it when I power on the the TV and let tubes warm up, it smells like it might be a resistor or something because it has a sort of "old dust" smell similar to the smell you get when you first turn your furnace on for the first time in the fall.

[vortalexfan]

OK new problem now, my power switch now is arcing and sparking out of nowhere, and I have no idea why its doing that.

I took the tuner apart and the only parts in there are a couple of ceramic caps and several resistors of which none of those parts look burnt so I sprayed some contact cleaner in the tuner on the contacts and worked the tuner knob around.

But as for the power switch/volume control and it arcing like it is, I'm not sure why it would be doing that.

Any ideas?

[vortalexfan]

OK so I figured out two of my problems that had cropped up, the issue with the smoking tuner was the tube I was using in my tuner, the 6AG5 tube of the tuner (which I didn't have any of to put into the tuner when I got the TV because that was one of the many tubes that was missing in the TV when I got it) was substituted out for a 6AK5 (which my tube substitution guide told me that was an appropriate substitute for a 6AG5 tube) but apparently the 6AK5 in this situation wasn't an appropriate sub for the 6AG5 as I think it was pulling more current than the tuner circuit could handle because once I swapped out the 6AK5 with a 6CB6 the tuner didn't smoke anymore.

As for the arcing power switch it was the rectifier tube I was using because I was trying some different 5U4 tubes in the TV and apparently the 5U4 tube I had stuck into the TV had some issues with it that only showed up when it was in circuit because when I stuck another 5U4 tube in the circuit the power switch stopped arcing.

but then yet another issue popped up, and it was in the audio circuit, R62, a 390 Ohm 1 watt resistor suddenly started smoking, and I'm not sure why, but I did have a raster on the screen of the TV just before I noticed the smoke from this resistor which I then promptly shut off the TV.

I did measure the 390 Ohm resistor and it measured extremely out of tolerance, it measured .475k Ohms which when I went to measure it in ohms it just measured O. L. on my multimeter.

I don't have any 390 Ohm 1 Watt resistors but I do have a 330 Ohm 1 Watt resistor, would that work, in place of the 390 Ohm resistor?

I did check and the resistor tolerances in the TV are 20% and 330 ohms is within the 20% tolerance of the original part.

[vortalexfan]

I actually did have some 390 Ohm 1 watt resistors in my stash, I replaced the original one with one of the ones I had in my stash and its still wanting to smoke for some reason, and I can't figure out why...

I'm so close to getting this TV going and this one resistor wanting to smoke is keeping me from getting there...

[vortalexfan]

OK so I think I for sure have figured things out this time, I double checked the Vertical and Horizontal Oscillator tubes and the Vertical Oscillator tube was one of the tubes that was missing in this set when I got it, and so I installed a
NOS Sylvania 6SN7GTB tube I had in my tube stash, which without realizing it should of been a 6SN7GT tube, because I didn't realize until just now that the 6SN7GTB tube is NOT the same as a 6SN7GT tube, the heater is Different and a few other differences as well, so I think that if I can get a new 6SN7GT tube installed in place of the 6SN7GTB I had installed in the TV that might fix my problem.

Unfortunately the 6SN7GT tube is over $20 a pop and I don't have that kind of money to throw around right now...

[vortalexfan]

OK so I had pulled the 6BG6 Tube out of the circuit and the current draw definitely fell quite a bit, but only down to about 160 watts which is what this TV is rated at when its running correctly which means something is still drawing excessive current yet in the set, but not sure what, as like I said all of the capacitors are brand new so the capacitors can't be the problem, the power transformer isn't the problem, the filter choke isn't the problem (i had confirmed from looking at the schematic that I had the filter choke wired up wrong which after I rewired it correctly, fixed the arcing problem with the 5U4 Tube).

So as of right now I've basically troubleshot and repaired everything that could of possibly been causing issues with this set.
The only other issues that could be causing problems in this set is the Vertical or Horizontal Output Transformers or the Flyback Transformer.