CTV 1974 PYE CT205; 697 Hybrid Chassis

Courtesy of @the_teleman I have plug No.5, the 12-pin that is missing from my timebase module. Hopefully, I can remove the hardwired terminations from the board, hopefully all, or at least enough of the edge connection landing remains intact, fingers crossed.

Hi Chris if the print on the edge of the panel is damaged or missing it can be replicated by using de soldering braid or the screen from thin co-ax cable. flattened and folded over the edge of the panel so it has a bit of support when you press the plug on. A tiny dab of two pack glue can also help reenforce it. You may have to open the edge connector out slightly to get the plug to fit.

A cosmetically nice looking example - and the veneer on the front edges of the chipboard cabinet hasn't chipped off. Mine was so bad that I peeled what was left of the veneer and stuck on black tape instead. It looks ok to me at least!

The other blue and white or maybe blue and yellow Dubillier cap to change is the A1 decoupling capacitor. It's C224 and is 0.1uF at 1kV. I've yet to come across a Pye hybrid either now or in the "olden days" where this doesn't go short circuit at some point taking out the associated resistor (100k) which then falls to some amazingly low value and to all intents and purposes shorts out the boost line - the PL and PY particularly don't approve of this! Annoyingly, the mains fuse takes an age to realise that there are these shenanigans going on and there is plenty of smoke from the aforementioned resistor and a destroyed PY500A!

The replacement PCB is coming on nicely too.

Tas

Removed the wires that had been soldered to edge 5, all were OK except the 4th from the left. There seems to have been quite a burn up just beneath. Those two points that are connected to the edge are the metal PCB chassis rail mount and a jump wire from JS5. I've done the best repair I can, it is what it is. There was another lifted trace between R303/R304 that was about to break so that was wire jumped.

I'm glad I just didn't go 'gung ho' and apply power, I'm not happy with any of those electrolytics and there's a few plesseys that have got to go.  A fair bit of work before this see any power. No doubt elsewhere, I would be deemed less than a hairy arsed dude with balls of steel, for not 'giving it sum' 😉 

Repaired

p.s.

The red fuse cover is not a PYE one. I rummaged in my stock and found an old Grundig power switch, it had a red cover over the back but was too large. Using my hot air workstation, I heated the long edges and slowly bent them over to form roughly the shape required. Again it's not perfect but far better than having nothing.

The plastic that keeps the 3 wires, Red, Green, Blue, apart from each other had fallen apart. I remember this was the same on my CT203/1, and I've seen the same on others who have this type. I used some Kapton tape and ties to make a new one. Again not pretty but serves its purpose.

A very neat repair Chris. The edge connectors were often chopped off and bypassed like that. A busy field engineer with 14 more calls to do in the day probably did that. "and off to the next one...!"  😀. I hated that yellow sticky stuff if it caught you unawares it could stick horribly to the hairs on your arm or make a right mess of your shirt! Yuk!  

As a slight commercial break in the proceedings, the mention up-thread of the Ekco version of this chassis had me rummaging through my box of brochures. Sure enough I found Ekco's 'Leap Ahead Year' 1972 fold-out A3 leaflet which features the sets in question. Its too big to scan, so I had to photograph it instead.

Incidentally I have fond memories of the Pye CT205 as it was our school tv when I was at primary school, c.1978. It sat on top of a tall metal trolley which myself and a friend were occasionally allowed the honour of wheeling along the corridor from the store room into position when we were due to watch 'Words & Pictures' or 'Music Time'. My main memory of the Pye was that it would display a very good picture even before the aerial lead was plugged in. Either we were in a high signal strength area (small village in rural south Nottinghamshire) or the set had extremely good gain.

Anyway, diversion over. Back to Chris's excellent work...

Steve

Posted by: @tazman1966

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A cosmetically nice looking example - and the veneer on the front edges of the chipboard cabinet hasn't chipped off. Mine was so bad that I peeled what was left of the veneer and stuck on black tape instead. It looks ok to me at least!

We would keep a roll of the trim in stock it was "Iron on" You heated it to make it stick leaving the outside edge clear of the cabinet and then sliced off the excess with a blade. It may still be available? 

Edit; it is ebay and amazon