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Old 12th Mar 2023, 5:30 pm   #101
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Default Re: Horizontal Output Transistor Question.

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Originally Posted by Red to black View Post
Be that it may Ben, the ICC7/8 wasn't a bad chassis, far more conventional than the ICC4 or 5, I did repair some ICC2 and 3 as well as 4, mostly Nordmende though.

The IKC2 did use the same Thyristor frame circuit and EW circuit as the ICC5 on their larger screen models but I digress.

@Luke the ICC2 did exist, it was fairly rare in the UK though, The ICC3 was probably better known as a B&O chassis here, The ICC4 I have only known as either the Nordmende or Telefunken plus one Thomson version.

Never seen an IKC1 chassis
IKC1 seems to have only been used on two telefunken models but a quick search reveals only those two, IKC2 must have come relatively quick as its successor.

ICC5 seems to have been their longest Chassis run, from what i can gather it was introduced in 1986 and i think the last model to use it was the 59P7 in 1990, at least its standard version, not sure about the IMC variants as i understand they were an entirely different breed with all their own suite of problems.

I used to have an ICC9 set also which i really liked, had a fantastic picture but had to scrap it due to an intermittent issue with flyback lines appearing every so often and having no repair knowledge at the time. From what I've seen on here the ICC9 was disliked perhaps even more than the ICC5. I also had a widescreen ICC17 that was a good set too but i gave it to a family member and last I heard it "Blew up" and it was never spoken of again.

Wondering if part of Thorns influence on Thomson included them continuing with the TX naming convention of their chassis alongside ICC. the TX91/92 sets had nice designs, i always liked the models with the front controls built around the speaker grills - T59F i think was one of them.
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Old 12th Mar 2023, 8:31 pm   #102
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Default Re: Horizontal Output Transistor Question.

The ICC9 was only disliked because nearly every Sm transistor failed at some point causing strange symptoms, engineers again disliked this chassis because again few understood it, once you got your head around how it worked it wasn't so scary.

It did need kid gloves all the same though! the ICC5 was a tame beast compared to this chassis.

The ICC17 was far more civilised and much better behaved, the biggest problem here being when the lopt failed it often took out the jungle chip which in this chassis was a sm 64 pin device which was the size of a postage stamp and not all engineers could replace it
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Old 12th Mar 2023, 8:44 pm   #103
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Default Re: Horizontal Output Transistor Question.

I think he TX chassis name was indeed a leftover from Thorn, only used for small screen and low end sets.

Was Thomson's Singapore factory originally a Thorn location?
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Old 13th Mar 2023, 1:58 am   #104
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Default Re: Horizontal Output Transistor Question.

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The ICC9 was only disliked because nearly every Sm transistor failed at some point causing strange symptoms, engineers again disliked this chassis because again few understood it, once you got your head around how it worked it wasn't so scary.

It did need kid gloves all the same though! the ICC5 was a tame beast compared to this chassis.

The ICC17 was far more civilised and much better behaved, the biggest problem here being when the lopt failed it often took out the jungle chip which in this chassis was a sm 64 pin device which was the size of a postage stamp and not all engineers could replace it
After the work i did on my Philips sets i know those SM transistors can be a real pain. I quite liked my ICC17 set, got it for 80 quid at a car boot sale, it must have only been about 3 or 4 years old at the time i got it, I got a lot of use out of it in the 2 years I had it and it never missed a beat, only gripe with it was it took it a minute to warm up before the picture was acceptable, used to always start up with a kind of yellow tint to it then it would normalize out and be fine. Wish i held onto it now but it was so big and heavy.

Back to my ICC5 - I changed DL22 again and RL22 for good measure and its been running for an hour now and the scan coils are still sounding normal, previously at exactly half an hour runtime they would get louder and thats not happened so looks like its finally sorted, i'll let it run for another hour and see how it gets on.
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Old 13th Mar 2023, 3:59 am   #105
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Default Re: Horizontal Output Transistor Question.

Well funny thing just happened, the set ran perfectly for two and a half hours, was just about to turn it off and as i was reaching for the remote there was a loud pop (scared the Shh out of me) set stayed on as if nothing happened but i quickly turned it off as it was the tell tale sound of a capacitor exploding....

Opened up the set and only took me a second to see that CL09 had its cover blown off but was still in place, interestingly enough CL09 is the only location with a brand new capacitor installed, the rest were all donated from other boards. I cant even blame the chassis for this one, this is purely a cheap capacitor at fault, I think i got a whole kit of them from Amazon with 50 different values for 10 or 15 quid, I'll route out another 100uF cap to replace it with ( i wont use any of those same caps again, absolute rubbish) CL09 is in the Resonator circuit QL07 so gotta make sure that area remains trouble free.
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Old 14th Mar 2023, 9:12 pm   #106
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Default Re: Horizontal Output Transistor Question.

That is very suspicious, I won't expect a explosive cap failure at that point.

Is RL11 still OK? It's a small PSU that delivers the voltage, if I am right around 8.5 volt. To blow up a capacitor that spectacular with RL11 (220 ohm) in series is very strange . .

Maybe QL7 got defective because of a malfunction of this supply. Is the voltage stable and withing range at CL09? Are DP45, RP45, TP45 and CP46 ok/no bad solder joints?

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Old 14th Mar 2023, 10:24 pm   #107
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Default Re: Horizontal Output Transistor Question.

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That is very suspicious, I won't expect a explosive cap failure at that point.

Is RL11 still OK? It's a small PSU that delivers the voltage, if I am right around 8.5 volt. To blow up a capacitor that spectacular with RL11 (220 ohm) in series is very strange . .

Maybe QL7 got defective because of a malfunction of this supply. Is the voltage stable and withing range at CL09? Are DP45, RP45, TP45 and CP46 ok/no bad solder joints?
I've just changed CL09 with a better capacitor and i have it running now and all seems good, i'll let it run for a while and if the same or similar happens again then i'll look at RL11. DP45,TP45 were changed as part of trying to solve the 'Dead' Problem.

I think (Im Hoping) this was just a once off due to really bad capacitor quality.
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Old 14th Mar 2023, 10:37 pm   #108
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Default Re: Horizontal Output Transistor Question.

Quote:
Originally Posted by IKC2E51R8 View Post
Quote:
Originally Posted by 3CX15000A7 View Post
That is very suspicious, I won't expect a explosive cap failure at that point.

Is RL11 still OK? It's a small PSU that delivers the voltage, if I am right around 8.5 volt. To blow up a capacitor that spectacular with RL11 (220 ohm) in series is very strange . .

Maybe QL7 got defective because of a malfunction of this supply. Is the voltage stable and withing range at CL09? Are DP45, RP45, TP45 and CP46 ok/no bad solder joints?
I've just changed CL09 with a better capacitor and i have it running now and all seems good, i'll let it run for a while and if the same or similar happens again then i'll look at RL11. DP45,TP45 were changed as part of trying to solve the 'Dead' Problem.

I think (Im Hoping) this was just a once off due to really bad capacitor quality.
What worries me is that CL09 is in series with a 220ohm resistor. Putting 8.5v on it through the resistor limits the current to 8.5/220 = 39mA when shorted. That can never blow up a capacitor like that unless, so the voltage had to be very high or the 220 resistor isn't 220 anymore when the cap failed . .
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Old 14th Mar 2023, 11:12 pm   #109
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Default Re: Horizontal Output Transistor Question.

Quote:
Originally Posted by 3CX15000A7 View Post
Quote:
Originally Posted by IKC2E51R8 View Post
Quote:
Originally Posted by 3CX15000A7 View Post
That is very suspicious, I won't expect a explosive cap failure at that point.

Is RL11 still OK? It's a small PSU that delivers the voltage, if I am right around 8.5 volt. To blow up a capacitor that spectacular with RL11 (220 ohm) in series is very strange . .

Maybe QL7 got defective because of a malfunction of this supply. Is the voltage stable and withing range at CL09? Are DP45, RP45, TP45 and CP46 ok/no bad solder joints?
I've just changed CL09 with a better capacitor and i have it running now and all seems good, i'll let it run for a while and if the same or similar happens again then i'll look at RL11. DP45,TP45 were changed as part of trying to solve the 'Dead' Problem.

I think (Im Hoping) this was just a once off due to really bad capacitor quality.
What worries me is that CL09 is in series with a 220ohm resistor. Putting 8.5v on it through the resistor limits the current to 8.5/220 = 39mA when shorted. That can never blow up a capacitor like that unless, so the voltage had to be very high or the 220 resistor isn't 220 anymore when the cap failed . .
I would think had there been a voltage spike the protection circuit would have kicked in and the set would have tripped, the set stayed on when the cap popped as if nothing happened. RL11 is still in place, unless its drifting with temperature changes... though the set had been on for 2 hours at the time so it had presumably reached peak operating temperature way before the 2 hour mark and so the cap would probably have popped earlier if RL11 drifted in value.

Also the other scenario if RL11 is permanently damaged the set most likely wouldn't have started up once CL09 was changed.

The set has been on for just shy of an hour now and so far so good, i'll keep an eye on it and see how it gets on.
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Old 15th Mar 2023, 12:21 am   #110
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Default Re: Horizontal Output Transistor Question.

Hello.

For CL09 to fail in such a way I'd certainly want to check the voltage across the replacement cap as 3CX15000A7 pointed out. A voltmeter hooked across it should be revealing.
Perhaps the failed cap was incorrectly marked regarding its voltage rating or may have had its polarity wrongly marked. I'd also want to have a look at those other new caps and do some tests on them to prove the point. It's never worth fitting poor/cheap electrolytic caps, they're likely to be a source of trouble. Good quality caps such as Rubycon, Panasonic etc are a good choice, even used pulls from older equipment are likely to be better than cheap new caps.

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Old 15th Mar 2023, 12:41 am   #111
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Default Re: Horizontal Output Transistor Question.

set ran fine for two hours, I'll keep an eye on it over the next few uses but i think its ok.

I think it was just a dud cap to begin with, and they were very cheap, the original cap was a 100uF 16v and the one that popped was marked 100uF 25v... it was however noticeably smaller than the original one so i do question its ratings. I've put a 100uF 16v from my scrap ICC5 chassis and it ran fine with it.

time will tell if it holds up, im hoping to have less bad luck with this set going forward.
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Old 15th Mar 2023, 7:01 pm   #112
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Default Re: Horizontal Output Transistor Question.

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Originally Posted by Philips210 View Post
Hello.

It's never worth fitting poor/cheap electrolytic caps, they're likely to be a source of trouble. Good quality caps such as Rubycon, Panasonic etc are a good choice, even used pulls from older equipment are likely to be better than cheap new caps.

Regards,
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....and most importantly, some electrolytics are low ESR types with a 105 degree maximum operating temperature. You must use the same type of capacitor...the cheaper 85 degree types won't be suitable (especially in switch mode power supplies). You need to check this when replacing any electrolytics to avoid expensive damage, the set just not working or failure of the cap itself.
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Old 15th Mar 2023, 7:31 pm   #113
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Default Re: Horizontal Output Transistor Question.

Quote:
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Quote:
Originally Posted by Philips210 View Post
Hello.

It's never worth fitting poor/cheap electrolytic caps, they're likely to be a source of trouble. Good quality caps such as Rubycon, Panasonic etc are a good choice, even used pulls from older equipment are likely to be better than cheap new caps.

Regards,
Symon
....and most importantly, some electrolytics are low ESR types with a 105 degree maximum operating temperature. You must use the same type of capacitor...the cheaper 85 degree types won't be suitable (especially in switch mode power supplies). You need to check this when replacing any electrolytics to avoid expensive damage, the set just not working or failure of the cap itself.
the original cap was an 85 degree cap and the replacement that popped was 105 degrees.
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Old 15th Mar 2023, 7:52 pm   #114
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Default Re: Horizontal Output Transistor Question.

Quote:
Originally Posted by Sideband View Post
Quote:
Originally Posted by Philips210 View Post
Hello.

It's never worth fitting poor/cheap electrolytic caps, they're likely to be a source of trouble. Good quality caps such as Rubycon, Panasonic etc are a good choice, even used pulls from older equipment are likely to be better than cheap new caps.

Regards,
Symon
....and most importantly, some electrolytics are low ESR types with a 105 degree maximum operating temperature. You must use the same type of capacitor...the cheaper 85 degree types won't be suitable (especially in switch mode power supplies). You need to check this when replacing any electrolytics to avoid expensive damage, the set just not working or failure of the cap itself.
Yes, I did actually know that having been in the repair business for many years but it was certainly worth mentioning all the same.

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Old 15th Mar 2023, 8:19 pm   #115
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Default Re: Horizontal Output Transistor Question.

In the early days of switch mode power supplies I remember finding a 10uF cap O/C in the start-up circuit. I just went ahead and changed it not taking any notice of the type I fitted. Confidently switching on, there was silence for a few seconds and then a loud bang....the TDA4601 met a spectacular demise with a hole blown in the side....(I was at Philips at the time). When I wandered into the tech advice department to get more info and ask further advice I was handed a new TDA4601 and a 'low ESR' capacitor. The helpful technician also gave me a circuit description of a typical switch mode power supply and why low ESR caps had to be used. The new chip and cap were fitted and all was well (after standing well back at switch-on)!! I have to admit that that first experience with switch mode supplies didn't inspire me with much confidence in them but, like everything else, it's all part of life's rich tapestry of learning....that must have been 40 odd years ago!
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Last edited by Sideband; 15th Mar 2023 at 8:25 pm.
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Old 15th Mar 2023, 8:30 pm   #116
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Default Re: Horizontal Output Transistor Question.

I've had bad experience with cheap capacitors from Amazon too, I bought them because I wanted something quickly for a prototype at the weekend but it was a mistake. 🙄
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