Telebar on/off switch issue

[Dave A]

Follow the lamp wiring also. It is clear that the lamps should only be on with the proper switch position...and wiring. The tv lamp wiring is from the "X" tap. The radio lamp wiring comes from the radio chassis via the "Y" tap. Not sure beyond that.

And I am confused by the jumper. Both sides seem to come back to the "X/Y" tap on the power transformer. Someone bail me out.

[Electronic M]

It may be a good idea to trace and copy the power wiring on the schematic from all sections, paying especially close attention to the switch wiring, on to a single piece of paper, and then go over it and try to under stand what the switches are doing and see if it makes sense.

On a Zenith Space Command remote set I have I had to stare at the schematic for a good 5 minutes to get what was going on with the two power controls...And on that set they had the courtesy to draw the entire PS of it on one page.

[Kevin Kuehn]

It's a lot easier to follow on the Riders schematic.

[jr_tech]

Yes! It would be really beneficial to see the wiring from the plug to the radio chassis including the radio switch. I can't figure out what the "logic" should be.

I assume the TV should have priority so if the radio is turned on, it will be turned off if the TV is turned on. Beyond that, tis a puzzle... When the TV is on, should the radio perhaps be in "standby" mode with heaters warm, or should it be *dead cold off*. If the radio switch is on, should the radio lights be left on when the TV is on, to perhaps indicate that the radio is in standby? Should the TV be in "standby" or "dead cold off" when the radio is on?
good puzzle,
jr

[bigaudioal]

Boy!! This one is gonna take some time.

I will try and post some diagrams from the original service manual I have, which should be the same as the Rider. Wish I knew what was supposed to happen with these switches so I would even know if I got it right someday.

Thx.

[bigaudioal]

Well, after taking a morning kindergarten class of cutting and pasting - here is the complete Admiral combo unit I have on a one page schematic. It is a PDF file and you can zoom in on it without loosing too much resolution. Assuming it uploads ok here. My specific combo is the 21L1 TV chassis combined with the AM/FM radio (5D2 model). I had to cut the radio portion of the schematic and paste it onto this page with the correct TV chassis schematic. But you can see the dotted line separating the two sections and they meet at the PLUG which connects the radio/phono unit into the back of the TV chassis. Looks like I need to concentrate on SW501 (just below the plug diagram on the right side of the schematic). This is the TV on/off switch.

Now based on my above video of symptoms and this schematic, anyone have any plan of attack for me that would yield a solution? I obviously need to trace the wiring in the set from the AC-in line through this switch and make sure everything is hooked up correctly. That is my first step. However, if someone can explain based on this schematic how the set SHOULD operate, that would be a huge help.

Thx. Let me know if the PDF file is not adequately viewable.

[Kevin Kuehn]

Here's the basic logic:

Both sets of A-B contacts are in parallel. So turning on either the TV or the radio connects AC line voltage to the power transformer primary.

When the TV -only- is switched on, the C-D contacts on the TV volume switch disconnect the radio circuit filaments of V601,602,603,604,605 and the two radio pilot lights.

When the radio -only- is on, the C-D contacts on the radio volume switch disconnect filament voltage from V101,102,V201,202,203,V301,303,304,306,V403,405,40 6 in the TV circuit.

Is there a TV pilot light I'm not accounting for?

[bigaudioal]

Originally Posted by Kevin Kuehn

Here's the basic logic:

Both sets of A-B contacts are in parallel. So turning on either the TV or the radio connects AC line voltage to the power transformer primary.

When the TV -only- is switched on, the C-D contacts on the TV volume switch disconnect the radio circuit filaments of V601,602,603,604,605 and the two radio pilot lights.

When the radio -only- is on, the C-D contacts on the radio volume switch disconnect filament voltage from V101,102,V201,202,203,V301,303,304,306,V403,405,40 6 in the TV circuit.

Is there a TV pilot light I'm not accounting for?

Yep, there is a pilot light on the front of the TV. On the schematic, it is all the way on the right side, to the right of the AC line plug. Right now, when I plug in the set it is always on and never goes off unless I unplug the set.

[bigaudioal]

I was just private messaging with Kamakiri. I was looking closely at the schematic and diagram of switch SW501. I then realized that none of the 4 outer lugs "A," "B," "C," or "D" should be directly connected to each other. Well, I vividly recall that there is a jumper wire connecting two of these lugs together on my switch with messy solder joints. I think this explains it!

So either one portion of my switch is not functioning and someone tried to fix it this way, OR the jumper was put there during partial restoration efforts before I got the set. Not sure which two lugs are jumper-ed, but I bet based on the symptoms in my video and this incorrect jumper wire, this accounts for what is going on.

[Kevin Kuehn]

Yeah, that makes sense that someone jumpered it as a quick fix.

Edit - That M505 jewel pilot light should be on whenever the TV or radio is turned on, as it's connected to pin 2 of the 6V6 audio amp filament. It's probably on constantly because of that same jumper wire.

[bigaudioal]

Originally Posted by Kevin Kuehn

Yeah, that makes sense that someone jumpered it as a quick fix.

Some fix. I cannot turn the set off. LOL!

[Kevin Kuehn]

Ok, it was a lazy cheap fix.

[bigaudioal]

HA!

I tracked down an NOS switch too. So if mine is in fact beyond repair, I can order a backup.

[bigaudioal]

Originally Posted by Kevin Kuehn

Yeah, that makes sense that someone jumpered it as a quick fix.

Edit - That M505 jewel pilot light should be on whenever the TV or radio is turned on, as it's connected to pin 2 of the 6V6 audio amp filament. It's probably on constantly because of that same jumper wire.

That jewel pilot light is pretty cool. Bright green. Looks cool with the lights out in the room.

[bigaudioal]

Confirmed! Half of switch is dead. Thus the jumper. I have ordered the NOS replacement switch and will try and repair the old switch as well.

Keeps me busy!!!