PS Ian,,I phoned my friend who has tons of vintage TV parts ,,He has a .022 1000 volt booster cap and its in the post should be here tomorrow,,,,,Thank you pete

PS Hello Monocrome,,,,Those 2 caps are poly booster cap

I tested Voltage a couple of times at G1 I got a Reading of 45 volts
I may have spare 6cm5 in the house in box somewhere

Thanks for guiding me through this and I hope I have not been pain in the ass to much,,,,,,,Pete

If the "picture screen" lights up, why are we trying to measure drive to the 6CM5, or trying to check for HT at the top cap.??
I'm confused.
JJ

OK, I thought you were telling me the screen does not light up - intermittently?

If the screen lights up, FORGET ABOUT the boost caps, they will be OK. You ave already told me they are "Di-Pol"s so they are NOT paper caps. If they were "Hi-Qual"s, they would be paper.

Put the cage back on the EHT and don't go there again!

If you get -45 volts on G1 of the 6CM5 the line oscillator is working. But we now know that anyway!

Now, what's the problem?

Hello,, ian & johnny,,

Yes I know that their poly caps,,,,,,I told that other guy on this thread they were poly caps not Paper, I dont know why he thinks their paper caps

Ok The screen lights up always ,,, I will put EHT cage back on ! !! """"Im in the badbooks"""
I will turn on Audio video modulator,,,put a dvd in and try what I can to get an image up,,

Thank you for your time ,pete

OK, if what I see in the uploaded pic is the best you can get, there could be an issue with your modulator. You are getting inverted modulation, the sync is showing up white.

What sort of modulator are you using?
What channel?
How is it connected?

Hello Ian,,,

Ian I have lot of vintage TV sets and all ways use the same modular,,,So as a test I have wired it up to my Pye pedigree TV,,,Which I know is in going order ....It wont work on it !!!!!!!!!!!!! I tested the voltage on the unit its fine at 9v
So I will go to Jaycar and buy a new one and see if we get a image

Ian,,all this started off just trying to find out why the Picture tube had a white dot in the centre that stayed on for a long time after the set was turned off!!!!

But now that's fixed !!!what fixed it?????? Which brings me to ask you a stupid question,,,1/Around the picture tube , between the tube and the frame was I black plastic tape like insulation ,,THIS was perished so I removed it and made another one!!!!!!!!!!

Was this perished tape causing the white spot in the screen ??????? magnetic field ? As the metal frame would of be touching the tube,????

I'm mechanic by trade so I'm right out of my depth here,,But I love vintage TVs and collect them,,,The only way I can learn to repair them is here.
from TV Tradesman like yourself,,,,,,Rest assure I dont take risks and I'm careful , .Apart from which my wife wont let me die while there is still Credit card Debt.

Thanks for all you have done.

I'll go to Jaycar tomorrow.

Hi Pete

Re your modulator, are you sure you haven't accidentally reversed the inner (active) and the outer (ground) video connection to the modulator?
Or maybe you are trying to tune it in on the wrong channel?

I can't quite visualise the plastic tape you talk about but that's a mechanical issue so what you did is probably OK. The CRT has a bonded faceplate so tape is not needed to hold it in place in the cabinet as it would be otherwise.

As I said earlier, if the graphite paint on the back of the CRT is not connected to the chassis, or if the CRT has not fully warmed up, you will get a spot on turn-off because the approx 20,000 volts on the CRT will not get discharged.

Ian

,,Hi Ian... Bought a new uhf vhf modulator from jay car

connected it up...no luck,,,tried every channel .

Things I've noticed that may give us some clues

1 no voices, no sound other than the normal crackling ?

2 every channel is the same , eg white no real waves or patterns and no variation on any channel """"They all appear the same""""?

3 The Picture tube is getting darker and I have less control on the brightness knob than I did in the past couple of days ?

4 the modulator Jay Car sold me has obviously been used before and shows wear marks on jack connections etc etc,,,,,I will be returning it to the store with and give them an ear full.

Well..I dont know what to look at next.

Thanks again,,,Pete

UPDATE !!!!!!!!!!! Picture tube has stopped lighting up !!This happened while I was typing post,,

what I did next

1/// noted all valve lighting up
2 went straight too booster cap
3 Discharge it

4 removed it and tested it with multimeter
reading was 38.NF

Cap is .a .022μF 1000 volt.

5 I want to check voltage at G1 6cm5 ? But I do not know if this test can be done with out booster ca pin place??? So I will wait to hear from you first.
thanks pete

PS New cap arrived in the mail ,,I tested it with my meter ,It reads 20nf on my meter,,,,The cap they sent me is ,,pm 223m 1.0kv ?????

This capacitor they sent is not a ploy ,,,its flat blue ,,I think that its Ceramic???

Hi Pete

Golden rule when fixing TVs - collect evidence and measure BEFORE you touch or replace anything!

Leave original boost cap in place and measure G1 of 6CM5. If it's -45 volts DC or thereabouts, line oscillator is running OK.

On the end of the boost cap that's connected to the red resistor, you should get about +610 volts. If so, EHT/Line Output system (and the boost cap) is probably OK.

If CRT is now dark, you will need to test the voltages on the CRT socket. Do you have the schematic?

Hello Ian,,,,Thank you,,,

I only have 1 page of the Schematic ,,,,See link.

https://drive.google.com/file/d/0B-yAJ2bw4-bcM2ZLck9nYmRLMUg2ZDU0N0pXWVlrX0xpU3hr/view?usp=sharing

I'lI read up tonight and get back to you,,,,,Thank you Pete.

Hi Ian,,,well here's where it's up too,


MY STEPS

1/ Unplugged it from the mains and then did a NCV Test

Answer/ Fine!

2 / Put Capacitor back in its place

3 / Set meter up and did a live wire recognition test
Answer/ fine!

4/ Unplugged TV from the mains

5/ NCV Test

6/ Set meter up on G1 6cm5,,,Put the meter on the floor and read it from a distance . Plugged mains in and read 45 VOLTS Negative .
Answer/ fine

7/ Unplugged it from the mains

8/ NCV Test



9/ Connected probe and alligator clip to Booster Capacitor on red Resistor side of booster Capacitor. & other probe to chassis ,Put meter on the ground so in can be read at a distance and the I turned the TV on at the mains.

answer/ Open Circuit

10/ Unplugged it from the mains

11/ checked I had the meter set right
Answer Yes

12/. NCV test


13/ Repeated test 9


Answer/ The Reading was Open Circuit on booster Capacitor .


food for thought?????? hahha

Thank you>>>>>>pete

No, I said measure the VOLTAGE on the boost cap, from ground to the end with the red resistor, with the TV powered up.

Hello Ian....Yep thats what I did

voltage tests on booster cap at the end where the Red Resistor is and to ground with TV turned on !

Eg 1 set meter to voltage

2/ connected probe to end of capacitor where Red Resistor is,,,,and other probe to ground and turned TV power on ,

Reading was OPEN,,,,so I repeated it again,,,,Reading was Open


????? Unless you mean that this test must be done on a warmed up TV "" when its warmed up place probes onto cap and and ground??

"""NOT Place probes on TV then turn power on "" ??????

I can do that ,If thats the correct way to do the test, But I will wait to hear from you first.