Old Muntz TV for sale Locally to me, Should I pick it up? - Page 7 - Videokarma.org TV - Video

vortalexfan · #91 10-02-2019, 08:56 PM

Quote:

Originally Posted by Kevin Kuehn

So what did you find out when you followed Electronic M's below procedure?

I haven't had a chance to try it yet.

I'm actually kind of afraid to disconnect the wires from the rectifier tube socket because I'm afraid I might accidentally reconnect them wrong and screw things up even more than they already are, especially since I don't which wires are the wires that Electronic M is talking about.

I did post a schematic of the power supply for this TV on here, if someone could mark on the power supply which wires are the ones I need to disconnect and test I can get a better idea of which wires to disconnect and test without risking disconnecting more wires than need to be.

Kevin Kuehn · #92 10-02-2019, 09:44 PM

Quote:

Originally Posted by vortalexfan

I haven't had a chance to try it yet.

I'm actually kind of afraid to disconnect the wires from the rectifier tube socket because I'm afraid I might accidentally reconnect them wrong and screw things up even more than they already are, especially since I don't which wires are the wires that Electronic M is talking about.

I did post a schematic of the power supply for this TV on here, if someone could mark on the power supply which wires are the ones I need to disconnect and test I can get a better idea of which wires to disconnect and test without risking disconnecting more wires than need to be.

Can you take a picture before you disconnect the wires so you'll have a reference to get them back to original? Not trying to be rude, but you need to take the initiative to follow directions and report back if you expect folks to help you troubleshoot this. If I can get the picture to load I drew a red line thought the connections you'll need to open.

vortalexfan · #93 10-02-2019, 10:37 PM

Quote:

Originally Posted by Kevin Kuehn

Can you take a picture before you disconnect the wires so you'll have a reference to get them back to original? Not trying to be rude, but you need to take the initiative to follow directions and report back if you expect folks to help you troubleshoot this. If I can get the picture to load I drew a red line thought the connections you'll need to open.

That's the thing that L1 coil doesn't seem to be present in my TV, the Focus coil is there but that inductor coil or whatever it is that L1 is supposed to be doesn't seem to be present in my TV, at least not that I can see of.

I'll take a picture of that part of the TV so you can see what I mean.

vortalexfan · #94 10-02-2019, 10:47 PM

Below is a picture of the power supply circuit on my TV showing that L1 does NOT exist in my set (at least not that I'm aware of).

Kevin Kuehn · #95 10-02-2019, 11:00 PM

Quote:

Originally Posted by vortalexfan

Below is a picture of the power supply circuit on my TV showing that L1 does NOT exist in my set (at least not that I'm aware of).

L1 is the small transformer(filter choke) to the left of the power transformer in your photo. Right above those electrolytic caps you've replaced. I can read the part number LG-10021 in your picture. There's only 2 wires exiting from it. One of the wires should go over to pin 2 of the 5U4 socket. It's also shown on page 4 in sams set 101, folder 5.

Kevin Kuehn · #96 10-02-2019, 11:22 PM

All you should need to do is remove the one small white wire from pin 2 of the 5U4 socket. If you follow that white wire over to your terminal strip it should connect to the plus end of one of the electrolytic caps and also to one of the black wires that goes to L1. It's possible you have a wiring error on your terminal strip, but for starters remove the white wire from pin 2 and see if that fixes the excessive current draw problem. Looking at your picture it seems to me that you have that white wire from pin 2 going to the negative side of that cap?

vortalexfan · #97 10-02-2019, 11:31 PM

Quote:

Originally Posted by Kevin Kuehn

All you should need to do is remove the one small white wire from pin 2 of the 5U4 socket. If you follow that white wire over to your terminal strip is should connect to the plus end of one of the electrolytic caps and also to one of the black wires that goes to L1. It's possible you have a wiring error on your terminal strip, but for starters remove the white wire from pin 2 and see if that fixes the excessive current draw problem. Looking at your picture it seems to me that you have that white wire from pin 2 going to the negative side of that cap?

now wait, L1 is the Focus Coil, which doesn't make any sense because L1 and the Focus Coil are marked as two separate items on the schematic...

Kevin Kuehn · #98 10-02-2019, 11:38 PM

Quote:

Originally Posted by vortalexfan

now wait, L1 is the Focus Coil, which doesn't make any sense because L1 and the Focus Coil are marked as two separate items on the schematic...

Nope. T6 is the focus coil and it's mounted on the neck of the Picture tube. L1 is the small transformer(choke) mounted under the chassis as I have it marked.

old_coot88 · #99 10-02-2019, 11:47 PM

Dude, take a deep breath and just clip the wire goin' to pin 2.

Now, measure from pin 2 to ground. If infinite resistance (open circuit), tube socket and power xfmr are not suspect. Short is 'downstream'.

vortalexfan · #**100** 10-03-2019, 12:28 AM

Quote:

Originally Posted by old_coot88

Dude, take a deep breath and just clip the wire goin' to pin 2.

Now, measure from pin 2 to ground. If infinite resistance (open circuit), tube socket and power xfmr are not suspect. Short is 'downstream'.

I unsoldered the wire and then tested pin 2 and it measured infinite like it should.

So where should I check next?

Tube TV · #**101** 10-03-2019, 12:43 AM

How many ohms is there between the ground and the white wire you unsoldered?

vortalexfan · #**102** 10-03-2019, 12:57 AM

Quote:

Originally Posted by Tube TV

How many ohms is there between the ground and the white wire you unsoldered?

There is 256.6 Ohms between ground and the white wire that I unsoldered from pin 2 of the 5U4 tube socket.

Kevin Kuehn · #**103** 10-03-2019, 01:04 AM

Quote:

Originally Posted by vortalexfan

There is 256.6 Ohms between ground and the white wire that I unsoldered from pin 2 of the 5U4 tube socket.

Is that white wire connected to the same point as the negative side of C1A & B as it appears in your picture? If so it needs to be moved to the plus end of C1A. Also check to see if R93 is in fact still 15 ohms.

Tube TV · #**104** 10-03-2019, 01:05 AM

That seems quite low, some of that could be the electrolytics loading the circuit down as they charge. To me it looks like its ahead of the transformer and rectifier.
You could power it up and watch the rectifier tube for arcing, and red plating.

vortalexfan · #**105** 10-03-2019, 10:05 AM

Quote:

Originally Posted by Kevin Kuehn

Is that white wire connected to the same point as the negative side of C1A & B as it appears in your picture? If so it needs to be moved to the plus end of C1A. Also check to see if R93 is in fact still 15 ohms.

It was but then I switched it around once I realized it was hooked up wrong.

I powered it up with that white wire disconnected from the 5U4 tube and it didn't arc anymore.

I'm guessing that means that the Filter Choke may be bad? How hard is it to replace those and how expensive are they to buy? Also how necessary is it to have that filter choke in the circuit? Can the set be ran without it in circuit?