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-   -   Philips G11.. Picture won't lock? Help please. (https://www.vintage-radio.net/forum/showthread.php?t=139974)

yampy187 20th Sep 2017 7:49 pm

Philips G11.. Picture won't lock? Help please.
 
3 Attachment(s)
Hi all.

I have a philips G11 that is a bit of a basket case. Ive managed to get it to this point. It was completely dead on arrival and found that to be down to D2015. After repairing a broken track and various dry joints on the LTB panel I have a picture of sorts. It won't lock correctly though.

The line and field hold controls seem to be working but just won't lock the picture. Looks more like 3 images bouncing and flickering all over the place. Would anyone happen to know what would be most likely to cause this?

I have been through the stock faults for the G11 with no luck.


Any help much appreciated.

Kind regards

Jan

volte-face 20th Sep 2017 8:06 pm

Re: Philips G11.. Picture won't lock? Help please.
 
You don't which model of G11, but if it is equipped with a teletext decoder it has to be operational for the sync circuit to be completed.

If the decoder is unplugged, or unpowered for any reason, then you will have a problem. There is a way round this by adding a link wire to re-establish the correct sync feed without the decoder present.

If, however, it is not a teletext equipped set, ignore this post!

yampy187 20th Sep 2017 9:50 pm

Re: Philips G11.. Picture won't lock? Help please.
 
1 Attachment(s)
Hi.

It is indeed a text set. Removing the screened lead from the bottom r/h side of the IF panel has got me a picture. Albeit very green. Looks like the tube is very flat!

Regards.

Jan

Tazman1966 25th Sep 2017 6:19 pm

Re: Philips G11.. Picture won't lock? Help please.
 
Before condemning the tube Jan, go through the grey scale setting up procedure. A1's are on the tube base panel and drives on the video panel. Good luck!

yampy187 26th Sep 2017 11:18 am

Re: Philips G11.. Picture won't lock? Help please.
 
2 Attachment(s)
Hi Tas,

The tube was well and truly shafted on all but the green which was also questionable. With nothing to lose I gave it a bop with the rejuvenator. After a greyscale and convergence the results are quite pleasing

Many thanks.

Jan

Tazman1966 26th Sep 2017 9:08 pm

Re: Philips G11.. Picture won't lock? Help please.
 
Looking very acceptable Jan. Nice to see that the plastic flap that covers the tuning controls is still present too.

Hybrid tellies 28th Sep 2017 9:10 am

Re: Philips G11.. Picture won't lock? Help please.
 
That tube has come up well. I always liked the Pye versions of the G11 they are much nicer looking.
Can you tell us what colour the main HT smothing can is? As if its the original it can cause a lot of problems.

yampy187 28th Sep 2017 9:59 am

Re: Philips G11.. Picture won't lock? Help please.
 
Hi there.

Thanks for the replies!

The smoother has been changed to a blue LCR type with the rivets. Pulled off another G11 PSU panel I had lying around. It still had the original pink one inside which was in good shape but I've heard the horror stories they can cause. The HT shooting up blasting a hole in the tube!

Could anyone tell me where the link needs to be added for the sync on the teletext board when it's no longer connected? I'm still having issues with it not locking all the time.

All the best. Jan

Sideband 28th Sep 2017 7:44 pm

Re: Philips G11.. Picture won't lock? Help please.
 
It's 30 years since I last did one of these but something in the back of my mind shouts' 5V supply missing' on the teletext board. There is an auxiliary supply that feeds the text board (down on the bottom of the cabinet) and if memory serves, if the fuse goes and removes the 5V supply to the text board, you lose sync.

volte-face 28th Sep 2017 8:39 pm

Re: Philips G11.. Picture won't lock? Help please.
 
To run without the text board, I think you should be aiming to ensure the continuity of the chain below -

IF Panel 5D6 ---> Decoder 6D5---> Decoder 6D4 ---> Timebase 2D13

I believe (although it may vary between different generations of TTX G11 - 600 or 700 series model numbers) that the text board fitment will normally break the link between 5D6 and 6D5.

If you do link those points manually to revert to non-text configuration, then you should probably unplug the text board completely to prevent any unwanted interaction.

If all those points are already showing the correct continuity and lock just seems unreliable, then you may need to run through the proper set-up procedures for the hold presets if you have moved them previously.

cmjones01 29th Sep 2017 9:27 am

Re: Philips G11.. Picture won't lock? Help please.
 
Why not get the teletext working? It's an important part of such a period set. It's no different to, say, the colour decoder.

Chris

cheerfulcharlie 29th Sep 2017 10:28 am

Re: Philips G11.. Picture won't lock? Help please.
 
Quote:

Originally Posted by volte-face (Post 978942)
To run without the text board, I think you should be aiming to ensure the continuity of the chain below -

IF Panel 5D6 ---> Decoder 6D5---> Decoder 6D4 ---> Timebase 2D13

I believe (although it may vary between different generations of TTX G11 - 600 or 700 series model numbers) that the text board fitment will normally break the link between 5D6 and 6D5.

If you do link those points manually to revert to non-text configuration, then you should probably unplug the text board completely to prevent any unwanted interaction.

If all those points are already showing the correct continuity and lock just seems unreliable, then you may need to run through the proper set-up procedures for the hold presets if you have moved them previously.

if panel module u5600
pin 17 chroma out
pin13 comp out
pin15 luma out
pin16 -lp

luma/chroma panel module u6200
pin 1 chroma in
pin 14 luma in
pin 7 comp in
pin 8 luma out
pin 13 chroma out
pin 11 burst
pin 6 blanking p
pin 7 burst gating


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