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

[vortalexfan]

Originally Posted by Electronic M

It will mess quite a lot up. This set uses a stacked B+ scheme. The audio output stage acts as a series dropping resistance. The video output, IF and possibly the tuner depend on the audio output to supply them with B+.

From here on out make sure the speaker transformer is connected on every power up of the chassis.

The speaker is connected now, and my higher voltage readings should reflect that fact.

[vortalexfan]

Ok so I measured all the voltages for the 6V6 and the readings I got are stumping me and don't make any sense to me:

Measurements made in reference to pin 8 of 6V6 tube

Pin 1: 0 V
Pin 2: 6.7 VAC
Pin 3: 25 VDC Should be 205 VDC
Pin 4: 21 VDC Should be 225 VDC
Pin 5: -177 VDC should be -8 VDC
Pin 6: -0.219 VDC Should be 0 V
Pin 7: 0 V
Pin 8: 0 V

Disregard what I said earlier about pin 4, I made the mistake of measuring that in reference to ground rather than to pin 8.

And actually, I just figured my problem, I had C3 and C4 wired in backwards because C3 just now vented with a loud popping noise, which I'm surprised it took this long to vent.

[Kevin Kuehn]

Originally Posted by vortalexfan

And actually, I just figured my problem, I had C3 and C4 wired in backwards because C3 just now vented with a loud popping noise, which I'm surprised it took this long to vent.

Bingo! Congratulations on finding that error. I was just about to ask you what voltage you measure on pin 8 referenced to ground, but it probably doesn't matter now. It does kind of irk me that Sams didn't provide a voltage reference for pin 8 relative to ground. I have no idea why they thought it was smart to put 0 volts relative to the same pin they have you measuring from.

[vortalexfan]

Originally Posted by Kevin Kuehn

Bingo! Congratulations on finding that error. I was just about to ask you what voltage you measure on pin 8 referenced to ground, but it probably doesn't matter now. It does kind of irk me that Sams didn't provide a voltage reference for pin 8 relative to ground. I have no idea why they thought it was smart to put 0 volts relative to the same pin they have you measuring from.

OK now that that's fixed and the TV is running as it should, (its running at 167 watts which is well within tolerance considering today's higher line voltages, and this TV was rated at 105-120V AC) now I just need to get a raster which its not producing inspite of having HV, Vertical and Horizontal running.

Its amazing though that one misinstalled electrolytic cap would cause that many issues.

[Kevin Kuehn]

Originally Posted by vortalexfan

OK now that that's fixed and the TV is running as it should, (its running at 167 watts which is well within tolerance considering today's higher line voltages, and this TV was rated at 105-120V AC) now I just need to get a raster which its not producing inspite of having HV, Vertical and Horizontal running.

Its amazing though that one misinstalled electrolytic cap would cause that many issues.

Amazing? Are you serious? You basically had installed a short circuit to ground across a significant portion of the power supply.

So now you are sure your vertical, horizontal, and high voltage circuits are all working properly? Or was that an assumption on your part?

[vortalexfan]

Originally Posted by Kevin Kuehn

Amazing? Are you serious? You basically had installed a short circuit to ground across a significant portion of the power supply.

So now you are sure your vertical, horizontal, and high voltage circuits are all working properly? Or was that an assumption on your part?

I saw the horizontal and vertical oscillators kick in on at the Kill-A-Watt meter when the TV was warming up, also I heard the horizontal and vertical oscillators running, which is a really high pitched whistling noise.

[Electronic M]

Originally Posted by vortalexfan

OK now that that's fixed and the TV is running as it should, (its running at 167 watts which is well within tolerance considering today's higher line voltages, and this TV was rated at 105-120V AC) now I just need to get a raster which its not producing inspite of having HV, Vertical and Horizontal running.

Its amazing though that one misinstalled electrolytic cap would cause that many issues.

The sounds you described are not a guarantee (and may not even be an indication) of working horizontal. To check....
If you have a working or non-working CFL that the glass is not busted on take that and place the glass against the H output top plate lead as well as next to flyback doughnut and see if it lights from the RF energy a working HV system produces... If it lights hold a well insulated screwdriver next to the HV connection metal contact with the set on and see if you can draw an arc. If it has over 1/4" arc your HV is present.

Once you confirm HV is present we can talk about making the screen light...

[vortalexfan]

Originally Posted by Electronic M

The sounds you described are not a guarantee (and may not even be an indication) of working horizontal. To check....
If you have a working or non-working CFL that the glass is not busted on take that and place the glass against the H output top plate lead as well as next to flyback doughnut and see if it lights from the RF energy a working HV system produces... If it lights hold a well insulated screwdriver next to the HV connection metal contact with the set on and see if you can draw an arc. If it has over 1/4" arc your HV is present.

Once you confirm HV is present we can talk about making the screen light...

I was able to confirm High Voltage, I was able to draw a 1/4" arc off the 1B3 tube's anode, however there is no high voltage at the picture tube's anode button.

[Kevin Kuehn]

If you haven't replaced it already, there's likely a 1 meg resistor in series with high voltage lead heading off to the anode button. The resistor is likely mounted under the 1B3 socket. They often go high in resistance or open.

[Electronic M]

Originally Posted by vortalexfan

I was able to confirm High Voltage, I was able to draw a 1/4" arc off the 1B3 tube's anode, however there is no high voltage at the picture tube's anode button.

Your HV rectifier tube is probably bad.

Edit: check that resistor Kevin mentioned first.