Pye v4

[Sideband]

Well done OTT. It's this sort of fault that was very satisfying to find back in the 'day'.

It's interesting working on some of these sets. Invariably the sets, be they radio's or tv's, were retired because of a fault and I've found that when you start working on them, the very last fault you find is the one it was retired for. All the others are due to it's being unused for so long. Most times, ceramic capacitors are fine and don't seem to deteriorate through lack of use so it's probable that this one failed 'in service'. It should be replaced with a similar component but you may be able to get away with an ordinary polyester...at least while testing anyway.


SB.

[oldticktock]

OK wired C75 in place, re connected C101 + wire to C18, reconnected leg of R131.

Powered up turned around whilst I waited for the line whistle instead I got a pop like a cap gun and a puff of smoke. Now i'm trying to see what went pop! nothing obvious so far. I only noticed the puff of smoke and it was on the right hand side of the chassis (photo wise)

This set is starting to make me laugh, I don't know why I just imagine it sticking it's tongue out at me as we progress though the issues as it throws another in my path. Perhaps this is the onset of 405 madness.

Very odd no signs of an exploded cap

[murphyv310]

Hi.
I am back. I see you have made progress but also had a set back, often the way of it, now you have HT to the "front end" its possible something else has popped. I would be powering the set up and having a look for smoke, dont worry about bangs its sore on the ears but these old sets are tough, try doing that on an LCD!

[oldticktock]

I had just walk round the front as the line whistle started to see what was on screen and pop

[oldticktock]

no smoke and we still have a full screen raster

[Boom]

I'd let it warm up anyway and see what happens. As Trevor says it won't do any damage. Probably another cap' kicking the bucket.

Dave

[oldticktock]

I touched R131 and its fine does not burn the finger now, i guess as the voltage ran through and past the R131 it found like you say another weak point

[murphyv310]

Can you apply a signal and try tuning it in?

PS R94 will most likely have changed value, also what voltage rating are the .0033uf caps you are fitting?

[oldticktock]

I was going to ask how you tune this in, I've only got experience of Bush TV62,63 they were Band1 & 3 and had turret with fine tuning. The only thing I can find is the dial at the back to choose alexander P, sutton, wenvoe etc, is that the tuner?

My aurora is set to defaults and the PYE is set to Alexander palace

[murphyv310]

Hi
Its a simple thumbwheel as you can see adjust it up and down near the ally pally mark, also turn up the sensitivity to max its the control on the back sitting on its own.

Make sure the aurora is set to channel 1

[oldticktock]

nothing, a bit more work required.

[murphyv310]

OK.
You will now need to check the voltages on V1, V2A, V4 & V5. There could be many reasons here including faulty valves, a resistor blown o/c by the previous fault or a duff cap.
When I did my V4 a while back I had to do every cap in the front end, no mean task I may add, but the set had been very damp for years but in the end it's worth it because the V4 will have the Bush's for breccy!
Lets know what you get (anodes, screen grids and cathodes exept V2A).

[oldticktock]

I will do that and I'm reading Chapter 3 of Spreadburys Volume 1 this covers the part of the receiver I'm in now.

[murphyv310]

OK Standing by.

You could phone for help PM me if interested

[oldticktock]

V1 EF80
PIN1(CATHODE) 1.8V
PIN3(CATHODE) 1.8V
PIN7(ANODE) 161V
PIN8(SCREEN) 161V

V2A ECC82
PIN1(ANODE) 80V
PIN3(CATHODE) 188mV
PIN6(ANODE) 137V
PIN8(CATHODE) 134V

V4 EF80
PIN1(CATHODE) 1.9V
PIN3(CATHODE) 1.9V
PIN7(ANODE) 161V
PIN8(SCREEN) 161V

V5 EF80
PIN1(CATHODE) 1.6V
PIN3(CATHODE) 1.6V
PIN7(ANODE) 159V
PIN8(SCREEN) 159V

Ones side of the ECC82 cathode looks suspect as well as the anode, guess thats my starting point

[murphyv310]

OK.
These voltages are roughly correct and I would say the various inductors are ok along with feed resistors, so its either a duff valve,s or decoupling caps.
Of course there could be an AGC fault but that's where you will need the use of a scope. One last thing make sure the contrast was up and not at minimum, these sets will just about cut off at minimum contrast,
PS don't forget my offer

[oldticktock]

Yep already had the contrast at max.

I will test the EF80's on the AVO but I can't seem to test ECC82's they go wild. I have two in stock that FERNSEH donated so I can sub.

I do have a scope, an old Solatron CT436, but that's a whole game I have not entered into and I do not have an isolation T/X.

already pm'd

I think for tonight as I've been at this all day (that brings it to 6 now, you guys must wince, and I apologise to Paul Stenning for creating another bloat thread) I will call it quits have a cuppa and take the advice you have all offered before to quit and start fresh in the morning.

Chris

[oldticktock]

Originally Posted by murphyv310

can you apply a signal and try tuning it in?

Ps r94 will most likely have changed value, also what voltage rating are the .0033uf caps you are fitting?

400v

[murphyv310]

Hi.
Again we have to agree this forum comes up trumphs for help.
I think we need to get a document together to help the likes of Chris and the correct procedure to repair a set like the V4, it must be very confusing for Chris to be bombarded by different people replying (myself included) perhaps one person that has experience of the set should guide the "person" on a one to one basis either on the forum or by some other means.
Anyway good luck Chris

[Station X]

I think the idea of a single mentor is a very good one. Let's keep things in the forums though. Lots of armchair TV restorers like myself like to follow these threads.