Hi guys, I am restoring an old Astor TV R52 G/8 and there are a couple of caps that are both labeled in the schematics as 220 and on the caps themselves with 220/360 the 360 volts is easy. 90% of the caps are in Milli-Farad .
there are two in this I have removed both one will read 222. pF in one of those Chinese component testers and the other nothing.
There is also one other with 2,5 listed in schematics and also on cap, but won't read in component tester.
And my fluke DMM range is 10nF to 9999 uF.

Any help would be appreciated

What chassis series is it? Series 8?

What C numbers? I can look them up and tell you what they are.

You won't have any caps in milliFarads! Anything that's marked as a whole number (e.g. "330") will be pF. If it starts with a . (e.g. ".022") it will be μF, microfarads. If it has a + and - on it, it's microfarads.

Unless you have wax paper caps (unlikely in a Series 8 as I'm assuming this is) there are probably no caps that need to be replaced.

The Ducon can electros in 60's Astors generally respond well to being reformed on a dim bulb. Not always, but mostly. So they do not need to be replaced.

And I can't see a 220pF cap anywhere. 200pF, but that's a ceramic and it will be OK.

What faults are you chasing? IRC Resistors, Anodeon pots and the 3 decal valves (6U9, 6X9, 6Y9) are the main offenders in that chassis.

Those flesh coloured Anocaps are polyester and definitely don't need replacing.

Don't even touch any of the caps around the IF traps or coils. Without special gear you will not undo the mayhem you'll create!

US Internet TV resto videos will give you the impression you can fix an old TV by changing caps.
Not in this case, anyway!

If you need help, my email is unhidden.

Hi, thanks for reply and yes, it is a series 8.
90% are the flesh coloured caps and they were label mF.
But unfortunately, it had been stored in a shed and dampness had corroded the leads on 50% of the caps on the board.
Oddly, corrosion only affected cap leads, go figure
the 2 caps I am having trouble are the ones I think they are polystyrene ones with a clear case and just has 220/630.
My assumption is that it was a 220pF but wanted to make sure.
the other one was an electrolytic with 2,5 on it and 160v. schematic shows it as 2.5 connected to pin7 of the 6JW8 to ground.

Cheers

The 220 pF caps you refer to are C113 and C121.

The 630V Ducon styros are blue.

Like all styros they have a habit of going open circuit, usually when cold.

Replace them with polyprop caps.

C129 is the 2.5μF cap on the cathode of the 6JW8. Its value is not critical and it only has a few volts across it. It could be replaced with a 1μF 63V MKT or similar, to avoid having to use a small electro in a hot position on the board.

Don't worry about the surface corrosion on the Anocaps' leads. It won't affect them. You could wipe the leads with a cloth and some CRC or similar.

The series 8 circuit was adapted with almost no changes from the very successful series 7 point to point wired wooden portable that was Astor's test bed for the then-new Philips Decal valves. I have one of these and one also appears in the movie "The Dish".