You need to test DC VOLTS, not resistance.

Hello,,,Ian,,,,,,something is wrong here Ian

The meter is set on Voltage autorange AC / DC the same as when I measured G1 and it Read 45volts,DC

I will check now on G1 again and then the booster and try to fine out whats a miss,

Thank you Pete


Ok update

Reading the Multimeter manual,,I have done it the correct way,,

G! tested again at 45 Volts DC

The meter has a DC limit of 1000volts DC,, so it should not be over limit ,But I feel that this is a meter problem if the voltage is under 1000 Volts DC

Ian,,,It must be over 1000 volts if meter is working ,Because Ol should not show up voltage mode only overload !

Meter is a Didtech Qm1321 from Jay car about a week old!

I can over ride autorange and test my theory and go into manual mode myself



UPDATE

Tested my theory and I'm Right ,The meter is shit and although the says it can do up to !000 VOLTS DC in AC/DC Autorange !!!! It can NOT!

When I override it and do it manually it reads 788 volts DC on cap end!!


My my apologies Ian !,,,,, I wanted to buy a Fluke but money is just too tight

I should of known that something was wrong when we were getting strange μF and Nf readings on the Capacitor the other day,,,,Bloody Chinese shit tools,,,,,Im sorry ,I did not mean stuff you about, I will have to get a new meter mate,,,Pete





UPDATE,,,,,I have the picture tube lighting up again!!!!!!!!!)))))))))))))))))))))))))))))))))))))))))))

what I did...checked every plug,,connections, made sure they were not loose,checked solders and reheated some if they looked suspect,,,removed valves and put valves back in,,,,,Turned on TV and tube lights up again,,,,does leave a white spot after turning off which stays about 40 seconds

Well I'm happy thats lighting up again

Hi Pete

It's very important to know the limitations of your tools. I use a couple of cheap meters and I have no trouble. But some meters will give you a crazy reading if there is an AC component superimposed over the DC, as there certainly will be in this case. Probably not fair to blame the meter, just be aware of that limitation.

I've just re-checked the schematic and the correct place to measure the boost voltage is on the OTHER end of that red resistor. The circuit shows 630 volts at this point. Because you don't know who's been fiddling, you will need to check it. Your meter should tell you the truth if connected here.

Measuring the B+Boost voltage (it is adjustable on your set - refer to the circuit and below) is a good clue to the health of the whole line deflection / EHT and CRT support system. So if the screen doesn't light, check that first.

B+Boost must be set correctly to ensure the long-term health of the TV. There is a pot to adjust it. Set it too high and you risk killing your irreplaceable "flyback" transformer. The correct range is between 610 and 650 volts. No higher, the lowest setting that gives you enough width is the best. The "throttle" pot is just above the 6CM5 and 6AL3, in between the two.

Once you set it correctly, leave it alone.

Just a tip from a very experienced ex-TV tech (me!):

When you are looking for an intermittent fault like yours it's important to disturb as little as possible. Look at the schematic, think and measure instead because otherwise the fault might fix itself.

This is NOT what you want!

Because it means the fault is not really fixed, it will come back again to bite you.

Hello Ian,,,First I would like to thank you for all the things you have taught me during this project . I have learnt a lot from you while doing this project,You would tell me things and I would read up on it late a night ,,,,,All about Capacitors,Resistors,Crt Coatings, multimeter readings the list goes on and on...I have a much better understand of things than before met you.Its been great and you donated your time to teach me some things I really want to learn,,,GOSH ! I'm sure I scared you at times and you probably wounded if I was going to be toast...

My wife is an Ex Electrical Engineer and at the moment she is over seas and we chat on skype each day....She also had Alarm bells going off about the OL Reading and thought I had the meter set wrong....But I didnt ,,It was just the limitations of that meter and it took me time to see that,,,but I did see!

UPDATE
1/ I took a reading of voltage at the booster.
! took a voltage reading from the other side of Resistor
It read
593 DC

2/ I increased it at at the Throttle Adjustment ,But the maximum I could get was
615 volts DC There is no more adjustment left to increase it anymore than 615volts dc

3/ But it does not stay at 615 volts,, As the TV gets warmer the voltage drops

615V
588V
582V

As this happens The Picture screen gets Darker and darker,

At that point , I switched it off at the mains as I was concern it may get Damaged

These reading were all taken on Manual mode !!

>>>>>>>>>>>>>>>>pete

OK, turn it down to close to minimum, which is about where it should be.

See the other white cap next to the boost cap? That's C123 on the schematic.
Is it a UCC Hi-Qual?
I'm hoping it is, and if so that's your problem. Replace it. Temporarily you can use that blue cap you just got for the boost cap position, the capacitance is not critical.

The other reason I suspect C123 is that fact that R159 (the red resistor) has been replaced.

If that's not it, there is a more sinister fault lurking.

Ian !!! This is a bit more interesting ! Have a read please.........

I knew which Capacitor you were relating too ,,Although I couldn't find C123 on the Schmetic,, ?? On the page I have the C's dont seem to go up to C123,,,But I knew where you mean ,,That Capacitor is a UCC Poly 100,.
.1PF 600 volts ,

I decided to Replace it,,So I took it to Jay car and bought anther one..Poly cap same value and voltage.

To install that cap I had to Remove The booster cap and 2 Resistors to get at it..

1 soldered new cap in place
2 Soldered Resistors back in place
3 Broke the wire off the original booster cap trying to fit it !!!!
BUMMER!

4 So, I got the cap the guy posted me and it was a PM 223M 1.0k,,! I worked out that PM 223M 1.0k = 22nf = .022 μF and is 1000 volts so I soldered that in place as a booster Cap

5.I traced the red wire from the c123 ? Cap and it goes back to capacitor connected to the rear of 6CM5,,,,All looked ok connection wise
.
6 Time for Voltage test on booster cap again,,Took reading from other side of red Resistor.

Reading was 560 volts DC .!

7 timed it with clock on the wall ,Within 2 minutes the voltage was dropping again

560
552
550

8 So with a 1000 volt Screwdriver I checked the Throttle pot to see if was in the correct position,

9,With the 1000volt Screwdriver inside the throttle ,I saw a Spark inside the Cage and it had appeared to come from 6CM5 ,,But the cage is on so its hard to say,

10 Turned it off at mains


11,,, I thought 2 things 1 did I bump ground with screwdriver inside of throttle pot??? or 2 Are the valve loose in the cage from open and shutting Chassis door all the time???

11 checked it was unplugged from mains, checked for power in TV with meter

NO Detection

12 Remover cage just to Look and check a Valve was not falling out.
NOT TO WORK,,,Just to look.

13 I could see that 6CM5 valves bakelite base was rotting and a piece was missing off the side.
I noted this was old damage not recent as it was brittle .

14 I Replaced 6CM5 with a secondhand spare I have with a good Bakelite bottom on it

15 put cage back on

16 set my voltage up on Booster again to take a reading

17 Turn on at the mains ! BINGO THERE WAS SOUND!! PICTURE WELL LIT!

with in a few seconds voltage was at 630 DC and Stable!!!!!
So I looked at the wall clock and monitored the time and voltage

5 minutes
630 volts

10 minutes
630 volts

18 minutes
618 volts

20 minutes
588


screen darker now !!!!!!!

I shut it off at the mains!!!!!!

well,,This tells me,, that what ever is wrong with the TV Tkes about 18 minutes to damage a 6CM5 valve and stop sound and screen lighting up .????????????
Im hoping this might tell you a lot more????????????????

Just a thought is it possible I have damaged the 2 small caps on the back of 6CM5 last week while using alligator
clips to measure voltage at G1 ?

well....I learnt some more>>>>>pete

I didn't think there was anything wrong with those Di-Pol caps.

I don't think there is anything wrong with either 6CM5. If you push them too hard you will often get flashover in a 6CM5.
Don't worry about the bakelite in the base, that happens to many 6CM5s with time.

Turn the "throttle" down to minimum voltage.

What is it now?

Does it remain stable?

If it does, check if you have enough width and that there is enough range in the brightness.
If so, leave it like that.
If not, bring it up JUST ENOUGH so there is. No more. Don't push it too hard, it's old!
Then see if that remains stable over time.

It's just possible that the line transformer ("flyback") is failing with shorted turns. I hope not, but it is wax and paper insulation. Treat it gently and it just might survive for a while.

Hello Ian Thank you..Looks like we have come to the end.!

No it does not stay stable and has no sound and the Picture tube goes dark after 10 minutes

Voltage drops to 560 in about 10 minutes

Ian,,Is there a place or somebody that can Recondition the Trasformer "" fly backs"" ??????

I dont want to loose this one the Cabinet is like new

Thank you ,,pete

First, check if either winding on the "flyback" transformer is getting warm after 10 minutes running.

Also look for signs of distress in the 6CM5 - does its anode (the rectangular grey box inside the glass) start to glow red, even slightly?

The flyback in these used to be very reliable compared to some others.
But as it has been sitting around for many years unused may be now suspect.
I would not right it off yet. Follow Ian's instructions.
Have you changed the damper diode(6AL3), as it may well be gassy.
JJ

Gday Ian,,

Well I can see no damage to 6CM5,,,No glowing on the Anode,! Only under it or above it,,,None at all on Anode

SEE PHOTO

After the TV had been on for 10 minutes ,I switched it off and felt for heat around Flybacks,,,

Yellow flyback a very mild warm "" very,,......,not hot !

Round Flyback was cold
this flyback has lost a small amount of wax

SYMPTOMS OF PROBLEM

1 Turn TV on,,The first thing you notice is speaker sound for only 2 seconds then ,,,There is no sound

/2 Picture tube lights up in 30 seconds from the time you turn it on

3 Voltage measured at the booster at the Time screen lights up is 615 volt.
But in 10 minutes the voltage drops and the picture Tube goes Dark.


Any thoughts Ian,,,??

PS I sat in a black room with no lights on and looked for sparks or Arcing around the Flybacks """"""""NOTHING""""

Thanks for your help>>>>>>>>>>pete

Hello Johnny, No I have not Touch 6AL3 yet,,

Hey did you see that guy who was selling the Astor Plymouth ,,He's Intentions were to turn it into a fishtank!!!!!!!! No Taste or morals !!!

Gosh!!! the things people do !!!!!!

All the best>>pete

When it goes dark, can you still see the filaments glowing in the CRT?.
What are the screen volts in fault condition, on the CRT.
Momentarily short the cathode of the CRT to deck, whilst in fault condition.Does the screen flash up ultra bright?.
Did you check the 4.7 and 2.2 meg resistors next to the boost cap(as mentioned by others also).?
JJ

Hello Johnny,,,No I have not tested CRT voltage,,,Im still trying to find out about the flybacks,,etc etc But yes I can still see the glowing filaments>>>>pete

Ok, I I'm onto something now, I used an Analogue meter to test all the Electrolytic Capacitors using the needle method , Out the 8 Electrolytic Capacitors that are in the chassis 2 were shorted and 1 other one ..That was tested showed possible leaking.
The poly Caps all tested fine.Only the Green Electrolytic Capacitors showed bad under analogue meter test,

I will replace the 8 Electrolytic capacitors ,,Thanks pete