l m a o :banana::yes::D

Well...OK. That was more one of my off the wall sarcastic comments on priority, but hey, OK then

ROTFLMAO :banana::D:yes::banana::banana::D:yes::thmbsp:

well later today i will be checking the crt with the bk440 crt tester on the cutoff mode and raise it up full and hope i dont get the blue glow. with the set on and working i didnt see any purple glow or anything glowing just the filiments but maybe this test will put this thread to rest on this set, if i get the blue glow. i do remember pulling the 6bk4 cap off and checking hv and it was around 24kv but when i pulled the crt plug off the hv went out the roof at over 30kv, and this was with the 6bk4 cap still off so either something in the circuit is holding back the hv or it may be the crt, who knows.

That does sound suspicious.
I have suspected that the roundie crts that have the copper pinchoff nipple leak. If you can clean the neck off and use a flashlight to look back at the pinchoff nipple and see if its glass or copper that would be interesting.

I would be interested in knowing what the symptoms of different amounts of air contamination are.
What happens if the crt looses 1-2hg vs 10hg, at what point do the filaments burn up...
Maybe miniman82 would know??

I would think any amount of air in the tube would cause the heaters to burn out very quickly. Witness how fast an incandescent light bulb burns out if it is broken while under power.

you know its funny i was thinking of the video you posted awhile ago about the crt that had the brass nipple on the end. what a dumb idea for holding back that much vacuum. and you seemed pissed at that finding.

there was something said somewhere in this site posted that the filiments wont glow in air but i dont remember what the explanation was about it.

A very tiny amount of air will make the tune unusable. The ability to make an image is destroyed long before the filaments are.

When I was restoring my 1965 Zenith roundie the CRT was gassy but I did not know it at first. On my crt tester the tube showed good emission, etc. I restored the chassis and got 25 kV on the bench at the anode connector. I assemble the set, power it up and get no hv and purple glow in the crt neck. There was no picture and the crt filaments did not burn out. After I had the tube rebuilt, changing nothing else, I had a great picture with proper hv. It sounds like you might have a slightly gassy crt. Don't give up on it. These round tube color sets perform great even if they are a little maintenance intensive.

well i did the high cutoff test for a blue glow and nothing not even the purple glow so im thinking the crt is ok. but i now remember when i got this set and finished recapping and powered up the horiz hold control would not work because the control didnt have enogh room to work so i had to tweak the oscillator a touch to get the control to work. but now after all that is the horiz oscillator and i did find the sweep setup instructions for the hv and i will have to go ahead and do it and maybe this is the problem. someone at some point must have touched that coil and who knows how far it was turned. i dont know if the horiz hold is ok that it means the frequency is ok because this could be a drive to the fly problem maybe due to someone turning that slug. this will be fun for me as i never had to do this befor but it is a learning thing always with these sets.

ok the hv sweep set up did nothing so now i took voltaqes off the video output tube pin7 is to be 230 v but i only get 152 v pin 8 140 v but i get 133 v and pins 3-9 is supposed to be 5v but im getting -0v so i am really lost here and i did try another video out tube. i also check the 6fq7 horiz oscillator tube voltages, pin 1 is 20v right on, pin 2 -.1v i get -.238 v and pin 6 245v i get 248v.

What is pin one of the video out tube? Does adjusting the contrast change these numbers?
Are you using no signal?

The brightness and contrast control will move those voltage a bit.
Maybe C3 is shorted, leaky or in backwards?
Maybe theres something up with C40 and the blanking isnt working right? or the resistors in that area....

Im sure you replaced C3 (250uf) just because its new doesnt mean its good.

well i really think im just going to leave this set alone because im making myself crazy and others. everything i looked at did not seem all bad and the crt thankfully is ok unless there could be gas in it and not show with a glow of any kind. its amazing it has a great picture my only problem with it is that a white pic is not so white, white scenes has kind of a reddish tint to it and at the same time the white shows the hv drops. so if this is all that bothers me then maybe ill live with it. small white scenes are fine just the ones that take almost the whole screen has the reddish tint and no matter what i adjust it is what it will be because the hv cant keep up or there just is not enough for whatever reason. i tried again today 24kv at crt 6bk4 cap off then with cap off i pulled the crt plug off and i get what looks to me is 32kv. why the crt plug in it wont go over 24kv this is the question. i did change c3 and im sure if it were backwards it would have vented or other things may be worse off then they are. again if the crt bias is raised even alittle bit then the screen should not bloom the way it does. so this to me is a weird mystery that maybe ill solve one day.

Look at where that cap is in the circuit, it goes from the contrast wiper to ground. If it was shorted it would cause biasing issues with the video out.

Yea take a break, you can come back to it later and will be freshend up. If I spend too much time on one tv my eyes start to blur out then I know its time for a few days off.

well if that cap were shorted then the contrast control would not work or work well? because it works very good.

If it was shorted it would work very well but it would shift the dc bias on the tube. Why not just check it?

is this cap right at the contrast control? a disc? ok that cap is electrolytic and its under the chassis. sorry for the brain fart it must be the storm coming.....

im looking at the schematic and that cap was a problem c3d says 250uf @50v but the can said 50uf@50v and c3c says100uf but it was 20uf on the can so sams was mistaken as always there were alot of mistakes. so i put in what was on the cans.

I hope you got your **** in order, everyone in that area, I know bryan and you, maybe a few others. Yall were lucky enough to get warning and get what you need.
I have never had to deal with something like this where you have warning. We have earthquakes that for the most part hit without warning, and we are due.

Ok, forget all that, cnn is on and the propaganda is melting my brain.

The values of that really dont make a big deal. You said the plate voltage was low and that would indicate a bias issue.

well dan how about i do this, what if i take the wire off the wiper pin of the contrast contol and check the cap that way ? this way i wont have to remove the chassis.

Hey, I have been following this thread and one thing seems to jump out at me. If the HV regulation is bad under load, what is the shape of the HV rectifier? Have you changed it? Is the filament lighting properly?

From what I have gathered on the thread, a big clue is the 32kv when the CRT is disconnected and the regulator cap removed. Putting on the regulator cap brings it down to 24kv with minimal loading by the regulator itself.

It is looking to me simply that the HV rectifier itself or associated circuitry (filament dropper resistor) is bad. But I think the key is the rectifier: if you have swapped it I'd try swapping again!

i have tried several rectifier tubes including a solid state tube. the filiment does light so its no that and there is no filiment resistor.

Sense he's able to get 1.5ma at the shunt cathode that rules out a HV issue. Something is overloading it. Gassy crt or bias issue

1.5ma?

If that is true, I agree it's a gassy crt or a bias issue.

how about the hot voltages which were 140v was right on but the other is -55.9V but the sams shows -50v so i really dont know if this could mean a bias issue. and with the set playing i get no color glows in the neck nor do i get anything with the crt tester in the cutoff mode as far as a blue glow, so im really lost and out there at this point.

1.5 ma and correct cathode current would indicate the hv is working ok. correct screen voltage is another really good indicator the hv is working right.

but the voltages at the 12by7a are not right.

The problem is the brightness control has way to much range and is over driving the video out.
Check r62 r64 and verify the brightness pot is not open

:Dok well i will close this thread by saying i am done with this silvertone as i just lowered the brightness readjusted the rgb drives and no more blooming with the bias up alittle to account for the weakest gun,RED and the whites are white now and no hv drop with whites. so i checked the brightness control pot and its right on at 250k and r62 and r64 both good as well as other resistors around the video output tube so in finding nothing else wrong here all i really did was lower the bright a touch so if this is what it took to improve what was wrong here well then i am going to leave it and take advantage of the fact that these sets had 10-20 or maybe 30% built in so if i am using a 10% leeway here well thats why they had this high of percentage, for errors because these sets were far from perfect so im happy with it now. well what more can i say,lol,lol...

See above. from page 5 some 40 post ago.

Talked to CTC-17 says he talked to you about too much brightness range, seems like something that could be figured out if you stick with that.

Remember also that these old sets will never be as bright as a modern one, I find that people overadvance the brightness control on a regular basis then wonder why the picture blows out. A weak tube will make things worse, so if you don't plan to get a new CRT I'd live with the reduced brightness.

yes it does seem now that the brightness control is driving alittle harder then it should and yes i can leave the bright reduced alittle but as ctc17 said when the sets were made no one would have wanted a new tv set that had to have the brightness lowered to fix other things. i would have thought the control was bad but it was not and the resistors as well are good. its not me overdriving anything to try to get a brighter picture, brightness was not the issue, hv and white colors and crt bias was so all these things are affected.:smoke: so ill leave it for now but i will keep this brightness issue on the back burner should anything related to that crop up.:smoke:

check the voltage at the plate of the 12BY7 with the service switch set to service.

ok, when i get a chance to get the back off again ill look in to that voltage at the plate. would you know off hand which pin is the plate otherwise ill look it up ?

Pin 7. What you are checking for is to see if the plate voltage drops to zero when in the service mode. I was doing some reading on RCA's and if this set has the same video out circuit, then it may have the same issue. If the 5.6k power resistor opens up (its on the service switch) you will lose plate voltage to the video out tube while in the service mode. The symptoms of an open resistor is very critical brightness setting.

ok, sounds like a possibility and i will get to it but i am certain in the beginning i went nuts checking everything and i do remember that resistor, its red and im sure i checked that one also. thats something like a 3-5 watt resistor. thanks davewm for that info, ill get on it. i just took a look at the schematic and there is 2- 5600 ohm resistors and a 2700 ohm so ill just chect them all as they are power resistors.

I am not sure you can test it in the circuit, so the best way to check is the voltage test at pin 7.