Which was the worst TV set / chassis you had to repair

[MickMcmichael]

Originally Posted by Michael Maurice

The Later LO6.1's and EM series which had the line output and E/W circuits on the live side of the mains, isolated by pulse transformers and optocouplers.

Yes they did, you're right. More nightmare memories!

Back covers acting like a load supporting wall and rounded corner cabinets on Sony's so as you couldn't pick them up without dropping them.

It was a time of over complication with little to gain up to LCD taking off and prices coming down.

[greg_simons]

Originally Posted by Richard_FM

I've heard the Philips G11s could be tricky to work with.

Not bad old sets but the reservoir capacitor could let go with very dramatic results, the huge eht spike generated could and usually did punch a hole right through the tube neck, did quite a few where the neck and scan coils had been decapitated from the rest of the crt.
Greg.

[Welsh Anorak]

Yes - I remember being at a Hitachi training day when they introduced the Tatung split rail chassis used in the portables. Even the lecturer was bemused by it.
The Philips LO6.1 was a reasonable chassis in the portable which then grew to 28" with all the attendant problems of that silly sub-panel.

[Red to black]

Despite the reports and dire warnings with the G11 I think I had only ever seen this once, what I did see on later sets with DC coupled frame output stage (several Vestal AK45s) was the tube entirely necked just behind the scan coils.

[Outrun_uk]

Sony’s with the dreaded GCS, or the later Hitachi’s with the blue posistor?

[greg_simons]

Originally Posted by Welsh Anorak

I'm surprised no-one's mentioned the Philips G9. A reasonable development of the G8, I suppose, but let down by those two big capacitors.
And where's the Pye CT200? Not too difficult to fix - usually - but that picture!
I think the German ITT was the FT100 with the 25kV overwind on the LOPT. Like the G9, you thought you were getting a CVC8 or G8 until too late.
Not vintage, but dare I mention the 55" Samsung curve with the screw-free back? Always a gamble that the screen will survive its removal...

Ah, the G9, we knew it was coming out and eagerly looked forward to it, the G8 had built such a good reputation for performance and ease of service the new chassis must be even better!, Oh, what a disappointment!, Terrible pictures untidy chassis layout and impossible to converge, happily philips knew it was a dud and replaced it with the G11.
Greg.

[Joe_Lorenz]

Hello,

my first vote is for the Russian "Raduga" = rainbow color tv sets of the 70s. These tended to catch fire for no obvious reason, so there was a word in former eastern Germany "The best friends of Raduga owners are the local firecrew".

My second vote is for early Blaupunkt CTV with 90° delta gun and three PFL 200 drivers that always showed rapid wear and had poor convergence from new.

Regards, Joe

[Red to black]

Hi Joe,
I an not familiar with any of the sets you mention but still interesting all the same.

[slidertogrid]

The G11 isn't a bad set it was a bit of a disappointment when it first came out though. I went on the Len Briggs lecture when it was launched. It was going to be the best thing since sliced bread ! it was going to beat the Japanese for reliability, give brilliant pictures .3 call rate they said...
The reality with early sets was somewhat different. The power supply blew up especially if plugged into the usual crappy old adapter or if the set had a slot meter fitted.
The frame chip failed, The Philips mechanical tuner switch unit drifted , the sets were plagued with dry joints and the smoother blew the tube neck off.
the later sets with all the modifications done and a tip switch channel selector were better but still suffered with dry joints e/w faults (remember the wilting coil?) buzzing chokes, frame chip holders becoming intermittent, intermittent tuners.
The audio and RGB panels were ok dry joints excepted. all of this said I liked the set and the later models lasted well past their expected life some lasting 15 years or more.
In fact I have one as a bedroom set. It was taken out of my spare room for temporary use when the Philips Ambilight packed up. The Ambilight proved to be beyond repair and was binned so the G11 is still there. OK the picture is a little bowed at the sides and I have to give the frame chip heatsink a wiggle from time to time when the frame jiggers about but it keeps going!

[bobbyball]

I actually have an example of the Blaupunkt set to which Joe refers above.

I think the chassis is a Telefunken derived one and the three colour output valves (RGB drive) are PCL200's, a valve not used in this country as far as I know.

My set is "part restored" and needs to be put back together and tried once I get chance, clearing late fathers' house very time consuming! Gigantic 26" monster with double (lockable) sliding doors. I cannot comment on it's likely reliability but it did come with one of the infamous Telefunken tubes (A66-120X) which had a terrible reputation. Static convergence is set from the convergence panel which seems to have enough controls!

The set was not particularly difficult to work on and has a rather nice "rainbow" effect colour control. It's one "nasty" is the unbelievably complex pushbutton unit, with band switching built in and multiple scales. It was in a bad way and took some considerable effort to get to work. Whoever designed it must have borne the world a grudge. Similar sets used the much better, if similarly frail, 7 way unit as used in the original ITT CVC5.

[Red to black]

Hi rich,
The G11 always seemed a bit dated compared to their continental cousins (I read the development article), the frame stage seemed odd in particular as I don't recall any other set using it.
It was fairly reliable compared to its UK counterparts of the time although I always found it a bit 'quirky' in a quintessential British sort of way

[Richard_FM]

I've heard the Thorn 3712 (or 3727) had a 17" screen that was almost impossible to get a balanced picture on even when new.

[ben]

Originally Posted by Welsh Anorak

- the Amstrad 2210. Looked stereo, made of chipboard and Fablon. A TDA 3652 frame stage that needed modification and never gave a linear scan. Plus a nice exploding PSU! They were best regarded as a posh box for a good 30AX tube.

We covered the Amstrad horror and the ICC5 in this fairly recent thread, if anyone wants some nightmares tonight !

I still think I had the last CTV2200 working (lasted till a few months into the new millennium!)

[Philips210]

Hi.

I remember having a large screen Panasonic TV (possibly Alpha 5W chassis?) in for repair which seemed to be in a distressed state. The PSU ran on a dummy load (60W filament lamp) so it seemed the line output stage was in trouble. Cold semiconductor junction tests didn't reveal any problems. The line output transistor and secondary supply rectifiers in the line output stage were fine. So all roads were leading to the LOPTx.

It's not too bad if you have a spare to quickly confirm but obviously I didn't have the correct transformer in stock. It was a special one with an extra loop winding on the core. Also, the replacement was very expensive, about £50.
I used my little LOPTx ring tester that I built from TELEVISION magazine (Sept 1993 issue) and it clearly showed moderate damping when displayed on the 'scope.

These sorts of repairs are always a sweat if the replacement is very pricey, and there's the worry that the problem is not going to be solved after fitting the replacement and then having to swallow the cost!
Anyway, the new genuine LOPTx arrived, fitted and all was well thankfully.Thanks also go to the TV mag for its useful LOPTx tester, which has helped me on many occasions.

Regards,
Symon

[Joe_Lorenz]

Hello Robert,

you are absolutely right: These early delta gun crt have quite a number of controls necessary to set convergence. In case of these Blaupunkts they came with thick service manuals giving strict instructions of doing what, when and how. A good pattern generator was a must. Yes, there were color amplifier stages using three PCL 200s, PFL 200s and even faster wearing out PL 802s.

But, alas, these days all folks were proud to own a CTV if they could afford one. My dad (mining engineer) got his first CTV in 1974 when I managed to rescue one from scrap and fix it.

Regards, Joe

[Philips210]

Back in the early 1990's I serviced a number of Huanyu 14" colour portables which were being used on a caravan park. They were clearly a Chinese copy of an Hitachi chassis but with cheapo components fitted instead of decent Japanese parts!
They were initially OK but as they began to age, which wasn't all that long, they produced a wide spectrum of odd faults. In virtually all cases this was due to duff electrolytic capacitors. Fault finding therefore took longer than it should have.

I remember the CRT final anode where the EHT cap connects to it, the cap was caked in white grease. At first it looked like it could have been heatsink compound, maybe it was! With a clean CRT bowl and a decent silicone EHT cap there shouldn't be any need for any grease.
I remember the quality Hitachi made diode split LOPT as used in the Thorn TX9. Never had a transformer fail nor any tracking with the EHT cap.
Talking of EHT caps, a lot of Philips TVs suffered from tracking of the EHT cap especially in damp conditions. The problem with their caps was that they were mostly made of PVC. ISTR there were special silicone EHT caps available which allowed you to also fit the high value resistor inside the cap as per the original. I'm fairly sure CPC used to sell them.

Regards,
Symon

[Heatercathodeshort]

Originally Posted by AJSmith625

With reference to Glyn's post #49, I had a G9 in the early 80s. Another freebie given to me by a mate also in the trade who I had done some work for. As I was going to keep the set myself the first thing I did was to replace the 2 troublesome electrolytics on the line OP panel, but as an experiment I decided to strap the new ones outboard on the vertical chassis strip at the back of the panel in an attempt to keep them cool and wire them into circuit keeping the wiring as short as possible. I never had to change these again and had a good few years use from this set.Alan.

Hello Alan. If ever a chassis got undeserved bad press it was the G9.
I sold the Roberts version, the Roberts Video RCT261. Other than the 2200uf cap mounted immediately above a hot wire wound resistor, I found the chassis to be very reliable. Snap! I also used to mount the cap on the chassis rail! Soft start power supply that never broke down and neither did the frame board. The combined G8 type decoder/IF panel just had the usual G8 faults.

Tripler failure often took the LOPT with it but it was a very cheap transformer so no problems. They were certainly more reliable than the G8 mainly due to the much improved PSU.

The German COMBI COLOUR was the CVC5 with the 25KV overwind. The LOPT used to fail and you could only get them direct from Germany.
The main reason was they we designed for 220V. Very few if any were modified for 240V with the result that the overwind, working on the edge of technology broke down. I think the company that designed them was LORENZ. John.

[dazzlevision]

Originally Posted by Heatercathodeshort

The German COMBI COLOUR was the CVC5 with the 25KV overwind. The LOPT used to fail and you could only get them direct from Germany.
The main reason was they we designed for 220V. Very few if any were modified for 240V with the result that the overwind, working on the edge of technology broke down. I think the company that designed them was LORENZ. John.

I only ever encountered one brand new and boxed "ITT Schaub-Lorenz" Combi-Color set and yes, they were badly "adapted" to work in the UK - by altering the intercarrier sound channel from 5.5MHz to 6MHz and precious little else.
I think they were imported unofficially by a UK wholesaler - can't remember their name though. Schaub Lorenz was a brand name of Standard Electric Lorenz - ITT's mains West German subsidiary and their TV factory was in Bochum.
I suspect that ITT Consumer Products in the UK were not very happy about these imports.

Around the same time, AEG-Telefunken (UK) Ltd, were importing Telefunken branded sets (709 chassis) from W Germany, but at least they did fit a mains autotransformer to avoid overrunning the fundamentally 220V set on the UK's 240V mains.

[Andrew2]

Although not actually a 'bad' chassis, the RBM A823 chassis made my heart sag a bit whenever one appeared on my bench. They were reasonably reliable, but even when firing on all cylinders the picture quality was dismal. No matter what you twiddled it remained stubbornly dull and lacking any form of sparkle or life.

Then there was the Sony line of 20 inch CTV's (can't recall model numbers of these). They were quite pretty sets, available as basic/remote/teletext versions and they all succumbed to the dreaded 'death by arcing mains switch' and cooking wirewounds in the LOP department. Sony's repair kit consisted of a pair of resistors and a length of HMP solder, and I seemed to spend half my life wrangling a larger-than-usual iron to do the job. Pity really as they were lookers and made nice pics.

Oh God I've just remembered. We were Thorn/BRC agents and we had lots of their tellies out on rent. Needless to say the bosses favourite was the 9800 chassis. What an abortion, they seemed to be made from leftovers from the 8000/8500 and bits & bobs from the 9000/9600 chassis. Wobbly mechanics, creaking cabinets. There was always at least one on the bench.

[Welsh Anorak]

The Sony was the 2090 / 2092 with the green spot you put on the back when you fitted the modified switch. Still got a small box of HMP solder which needed a Weller gun to melt and always looked dry. Good TVs otherwise.
I agree - never got an A823 to give a sparkling picture, especially the two-chip version, even with a new CRT. Apparently some beam limiter resistors could change value, but I didn't see any improvement.
The 9800 was clearly a 'what do we do with these panels while we wait for the TX9?' chassis.