1950 Admiral 16" Set; Recapped... No Picture!!

[Notimetolooz]

Do the color codes on the parts match the value on the schematic?
At least one of the parts in the bottom row look like it may be a coil.

[Notimetolooz]

Originally Posted by Magnavox300

Okay, replaced all resistors as needed, and now just waiting for the 6CD6 tube to get here...

Quick question: there is a .47 capacitor ( C211 ) off of the 6AV6 tube, which I replaced, but Sams and Rider schematics both show it to only be a .047...
Did they make a mistake at the factory?

Why did you not remove the old wax paper capacitor? It isn't still connected is it?

[Yamamaya42]

Originally Posted by Notimetolooz

Why did you not remove the old wax paper capacitor? It isn't still connected is it?

hard to tell from the pic, but perhaps it is just being used for support.

[Magnavox300]

Originally Posted by Notimetolooz

Do the color codes on the parts match the value on the schematic?
At least one of the parts in the bottom row look like it may be a coil.

Yes, the color codes do match the schematics values, all except the 2 small brown resistors tied together, they only have one green stripe each, but are close to the schematics value when measured...

Also, the old wax capacitor shown was riveted in place, and I just figured I'd leave it and use it for support, as Yamamaya said... though I did cut it out of the circuit...

[Magnavox300]

I put in a temporary 6BG6 tube, and got light on the screen...
figured i'd replace about 8 resistors that were not close in spec... now I get nothing.
So frustrating...
I have learned with electronics it can usually be a very simple overlooked item, like the wrong value resistor, bad soldering job, etc...I have rechecked my work over and over.
I even went ahead and put back the old resistors just to see, still nothing.
In the future I think I'll replace one component at a time and see if ieverything still works before proceeding...

[Magnavox300]

Okay, finally figured out what I did wrong...

I replaced the 2.7ohm resistor under the 1B3 tube, with a 27ohm!
I installed a new 2.7 but still no picture?

Could I have done any damage to something using that over valued resistor??

[Electronic M]

No damage should have come from using the high resistor....it would be no different from a HV rect with an open heater.

Have you tried holding a CFL light bulb next to the flyback and or H output tube with the set running to check for drive to the flyback?

[Magnavox300]

Originally Posted by Electronic M

No damage should have come from using the high resistor....it would be no different from a HV rect with an open heater.

Have you tried holding a CFL light bulb next to the flyback and or H output tube with the set running to check for drive to the flyback?

Thanks, good to know that didn't hurt anything...
Yes, I just tried the bulb now... Looks like the flyback is running...
The only difference in what i did, is that the 2.7ohm resistor was originally a
1 watt; my replacement is a 1/2 watt...
Schematic only calls for a 1/2watt.
Old Coot said it should be fine...

[JohnCT]

Originally Posted by Magnavox300

The only difference in what i did, is that the 2.7ohm resistor was originally a
1 watt; my replacement is a 1/2 watt...
Schematic only calls for a 1/2watt.
Old Coot said it should be fine...

OC is right.

If you have a pulse at the fly and no HV, the rectifier tube is the next suspect.

What I would do if I didn't have a HV probe handy is to hold an insulated screwdriver at my fingertips and touch the cap of the HV rectifier tube. In a dark room, you should see the soft blue arcing between the tip of the screwdriver and the cap. Make sure the tool keeps at least two inches of plastic between your fingers and the metal shaft. If that CCFL tube lights, you should get a soft arc from the cap of the HV rectifier tube to the screwdriver.

If you see the arc, move to the anode connection on the picture tube and see if you have it there. If not, the HV rectifier tube or doorknob cap might be bad.

John

[old_coot88]

The 1B3 filament glows a soft orange when in operation. In a darkened room, you should be able to see it glowing if you look up from underneath the tube. No glow = no go.

[Yamamaya42]

Originally Posted by old_coot88

The 1B3 filament glows a soft orange when in operation. In a darkened room, you should be able to see it glowing if you look up from underneath the tube. No glow = no go.

mine was bad... REALLY BAD.
https://imgur.com/z7NnpHg

while I waited for a new one to come, I got it to work by ripping apart an old microwave and using the HV diode in there.

[old_coot88]

Originally Posted by Yamamaya42

mine was bad... REALLY BAD.
https://imgur.com/z7NnpHg

Hm... talk about gaslighting.

[Electronic M]

If the rect heater is good and lighting but there is no HV at the CRT you can check the doorknob capacitor by disconnecting one end. Make sure that which ever end you disconnect you slip a cup, saucer small jar or some other glass or ceramic insulator in the disconnect gap to prevent arcing.

[old_coot88]

Originally Posted by JohnCT

...you should get a soft arc from the cap of the HV rectifier tube to the screwdriver.

If you see the arc, move to the anode connection on the picture tube and see if you have it there. If not, the HV rectifier tube or doorknob cap might be bad.

Small quibble, but you won't get that 'air arc' from the CRT anode like you do from the 1B3 cap, since the CRT anode voltage is DC. The 'air arc' is from high level RF ('fly-back') spikes from the flyback.

[Yamamaya42]

A b&k hv probe is not TOO overpriced these days, are they?