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Old 10th Mar 2023, 12:27 am   #81
IKC2E51R8
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Default Re: Horizontal Output Transistor Question.

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The difficulty now is if some of the replacement caps are secondhand/used or new? without a 'scope you are severely limited as to what is what, it is possible a few out of spec parts have introduced new faults while trying to rule out others!

you see not all of those components you have changed while fault finding will be faulty, we were just going off of stock faults or a 'suck it and see' approach, this is not really the way to fault find properly.
Components where a mixed bag of new and old parts, pretty much whatever i had lying around but if they were used they were known working the last time they were used (mostly from the previous ICC5 board). Getting a scope wont be happening anytime soon due to lack of funds.

the trouble i have now is i could of course go back over the many parts i changed but in doing so i risk re-creating the original fault which ideally I want to steer clear of.

For now i'll have to just keep trying things and hoping for the best.
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Old 10th Mar 2023, 12:32 am   #82
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Default Re: Horizontal Output Transistor Question.

understood mate, I will try to help where I can.

You should try an acquire a scope at some point though as this will open up a whole new world where you can see what is happening, it won't of course give you all the answers but it will allow you to see what is and isn't to blame and give you a much better idea.
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Old 10th Mar 2023, 12:47 am   #83
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Default Re: Horizontal Output Transistor Question.

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understood mate, I will try to help where I can.

You should try an acquire a scope at some point though as this will open up a whole new world where you can see what is happening, it won't of course give you all the answers but it will allow you to see what is and isn't to blame and give you a much better idea.
Thanks, I really do appreciate it, I will at some point get a scope (I've always intended on getting one since i started fixing this old stuff).

Wont be looking at the ICC5 again until some stage tomorrow, I've a few ideas of where i want to look and thankfully I posted all the parts i changed here so I have a place to start, I've also just found some brand new low value Caps i had stored in a mug of all places which might do to replace some of the 2nd hand low value ones i threw in that were already probably past their best so thats my starting point the next time i look at it.
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Old 10th Mar 2023, 10:39 am   #84
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Default Re: Horizontal Output Transistor Question.

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So the horiz line being locked to the vertical video sync seems to rule out any mains related interference. I wonder if there is a clue in the fact that the rogue line /s is slightly phase shifted from those either side ?
Would be nice to see an effected sync pulse on a scope.

Les
On this chassis the line and field (also the psu) are locked together by division/subdivision of the master clock QL07 in the power processor LC TEA2029C IL14, hence no line or field hold controls.
Thank's for that info, as I'm not familiar with that chassis I'll slink off, do some homework on the chip, keeping an eye on the thread.

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Old 10th Mar 2023, 4:02 pm   #85
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Default Re: Horizontal Output Transistor Question.

I could be wrong but is it possible that the horizontal line is a locked 50hz or 100hz psu smoothing artifact in the frame stage? Just a thought and probably wrong.

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Old 12th Mar 2023, 11:49 am   #86
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Default Re: Horizontal Output Transistor Question.

Opened the set again last night and changed CL58 (158v supply to lopt ) changed it as it had gone low in capacitance and then looked at CL21 in the soft start circuit for IL14 and noticed the pad had been damaged slightly when changing that cap at an earlier stage, i replaced the cap as the ESR was crazy on it and fixed the pad.

Powered on and both the vertical line down the screen and horizontal across are both gone. picture is fantastic on it now, set is currently on soak test now with a playlist of music videos so i'll see how it gets on, hopefully all issues have finally been resolved.

EDIT: it still has the issue with the scan coils getting very loud after about half an hour. everything else is perfect and when the coils get louder the picture stays perfect. What could cause this?
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Old 12th Mar 2023, 12:21 pm   #87
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Default Re: Horizontal Output Transistor Question.

Good to hear the set is working again. That with QL7 is e very tricky fault you don't expect.

Are you sure it are the scan coils and not the linearity coil?.

How is the picture compared to the philips gr2.2? They both are from around the same timeframe and both middle class.
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Old 12th Mar 2023, 12:35 pm   #88
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Default Re: Horizontal Output Transistor Question.

It sounds like it is mostly the field scan rattling the coils as the line stage is just above sonic levels @15.625 kHz, without scoping though this is just conjecture.

It is possible that the 50 Hz field scan (or EW correction) is modulating back into the the lower level circuits of IL14, a diode in parallel with the field output Thyristor DL21, that would be DL22 and its associated filter CL22 and RL22, plus also at the other side of the field scan coils are RL50, RL58 and CL54, also remember that a winding 4 and 11 on the lopt LL53 provide the field scan action via Thyristor DL21 on this chassis.

Ps. I have had DL22 BA157 faulty on multiple occasions also RL22 1k5 however you usually get visual frame faults with these two components, I have also had CG11 1n give poor EW as well just not common.

Ps2. I have also had DL21 (field output thyristor) ESM740G cause problems in the past too, again it wasn't common at the time but nevertheless has given problems in the past. DL21 and 22 should be replaced together as a pair for repair purposes btw.
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Old 12th Mar 2023, 1:48 pm   #89
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Default Re: Horizontal Output Transistor Question.

At Luke, I am not really an expert with this chassis, just I bought hundreds of them back in the day, we got them on pallets of at least twenty, sometimes fifty so I had to fix them, albeit at the time they hadn't aged as much as now.

Even then Thorn had little appetite in fixing them, neither did most of my local repair shops so most ended up on my bench one way or another, so I ended up fixing more than my fair share!

I wasn't particularly impressed with the short lived in the UK at least of the IKC2 chassis, we only had really two models here, 41P3 and A51F, these were less reliable than the previous ICC5 and the later ICC7/8.

The IKC2 had its own problems with servicing, not least its propensity to spray EHT around when its lopt failed in spectacular fashion unlike the ICC5.
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Old 12th Mar 2023, 2:51 pm   #90
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Default Re: Horizontal Output Transistor Question.

ICC5 lopts did fail in spectacular fashion but I think mostly in the Telefunken version of the chassis. I think they were made by Orega, and possibly similar to those used in the IKC2.
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Old 12th Mar 2023, 3:27 pm   #91
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Default Re: Horizontal Output Transistor Question.

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ICC5 lopts did fail in spectacular fashion but I think mostly in the Telefunken version of the chassis. I think they were made by Orega, and possibly similar to those used in the IKC2.
I also think the UK/Thorn versions of this chassis used mostly Orega types too, however the ICC5 failed generally with the three trips variety, having said that I had very few Lopt failures with the UK ICC5 sets, maybe a handful at most.

We did see some continental ICC5 sets either Telefunken or Nordmende maybe the odd Thomson badged import, and oddly a few Hitachi badged sets, but too few to notice any trend here.
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Old 12th Mar 2023, 3:28 pm   #92
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Default Re: Horizontal Output Transistor Question.

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It sounds like it is mostly the field scan rattling the coils as the line stage is just above sonic levels @15.625 kHz, without scoping though this is just conjecture.

It is possible that the 50 Hz field scan (or EW correction) is modulating back into the the lower level circuits of IL14, a diode in parallel with the field output Thyristor DL21, that would be DL22 and its associated filter CL22 and RL22, plus also at the other side of the field scan coils are RL50, RL58 and CL54, also remember that a winding 4 and 11 on the lopt LL53 provide the field scan action via Thyristor DL21 on this chassis.

Ps. I have had DL22 BA157 faulty on multiple occasions also RL22 1k5 however you usually get visual frame faults with these two components, I have also had CG11 1n give poor EW as well just not common.

Ps2. I have also had DL21 (field output thyristor) ESM740G cause problems in the past too, again it wasn't common at the time but nevertheless has given problems in the past. DL21 and 22 should be replaced together as a pair for repair purposes btw.
I changed DL21 and DL22 which is when i noticed the scan coil noise, i then changed DL21 again for another thyristor thinking that might be the problem but i didnt replace the BA157 again yet, i might do so and see if it could be a dodgy diode.

RL22 measures fine so i left it but i might change it in case its drifting when warm but like you said i would expect visual indicators on the screen if they were going bad but the picture stays perfect including the EW.
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Old 12th Mar 2023, 3:40 pm   #93
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Default Re: Horizontal Output Transistor Question.

@ Maarten
In the UK we saw a few ICC5 and ICC7 sets badged up as Hitachi, these were very different to most UK sets in that they had no OSG with the ICC5 variants and relied on local keyboard control for tuning etc.. they were more akin to Salora,Lowe European input techniques via the local keypad than any other sets of this era.
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Old 12th Mar 2023, 3:42 pm   #94
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Default Re: Horizontal Output Transistor Question.

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At Luke, I am not really an expert with this chassis, just I bought hundreds of them back in the day, we got them on pallets of at least twenty, sometimes fifty so I had to fix them, albeit at the time they hadn't aged as much as now.

Even then Thorn had little appetite in fixing them, neither did most of my local repair shops so most ended up on my bench one way or another, so I ended up fixing more than my fair share!

I wasn't particularly impressed with the short lived in the UK at least of the IKC2 chassis, we only had really two models here, 41P3 and A51F, these were less reliable than the previous ICC5 and the later ICC7/8.

The IKC2 had its own problems with servicing, not least its propensity to spray EHT around when its lopt failed in spectacular fashion unlike the ICC5.
I appreciate all the help everyone has given with this set, id be lost without it frankly, these all hit the market around the time i was born, i was only a few months old when my mum got a 51K5 that lasted about 5 years, its the first TV i remember watching (and witnessed failing).

in terms of picture quality I generally prefer the picture on the ICC5 though the GR2.2 is a very close 2nd in terms of quality, where it really shines is the sound, none of my other sets sound nearly as good as the ICC5.

I'll open it back up this evening and replace DL22 and I'll look at replacing RL22, RL50 and RL58 and CL54 has already been replaced.

after that im not sure what else it can be but i'll change those parts and see how it gets on.

I have two A51F sets which i love, both in fairness have never really given me much trouble, one of them did begin making a noise like arcing one day but I was aware of how the LOPTs can wipe out an IKC2 chassis so i powered off and replaced the LOPT before any major damage was done, its been working perfect ever since. ive also got a SABA 14" portable in the same style as the A51F using IKC2 which is a nice little set and looks much better than any of the 14" Vestel stuff i have crowding the attic.

Am i correct in saying that the IKC2 was essentially the last chassis thorn had any influence in modifying (custom OSD etc) as everything after ICC7 and beyond all seemed to be stock Thomson.
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Old 12th Mar 2023, 3:57 pm   #95
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Default Re: Horizontal Output Transistor Question.

You are correct in that the IKC2 41P3 and A51f were the last chassis that Thorn modified the OSG, however the IKC2 also had larger screen sizes in Europe namely with 110 degree tubes which we didn't have here.

Thomson also influenced Thorn after their takeover so who influenced who is debateable

Ps, the TX80 was also heavily influenced by Thorn
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Old 12th Mar 2023, 4:34 pm   #96
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Default Re: Horizontal Output Transistor Question.

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You are correct in that the IKC2 41P3 and A51f were the last chassis that Thorn modified the OSG, however the IKC2 also had larger screen sizes in Europe namely with 110 degree tubes which we didn't have here.

Thomson also influenced Thorn after their takeover so who influenced who is debateable

Ps, the TX80 was also heavily influenced by Thorn
I can see why Thorn Modified it, their version is much nicer than the stock Thomson one. There was also Stereo Versions of IKC2 too (at least according to some of the IKC2 manual's I have) from what ive seen IKC2 seemed to enjoy greater popularity with Nordmende and Telefunken Badged sets. interesting that IKC1 is never really mentioned though it must have existed at some point and after IKC2 they never continued that naming convention. Similar to ICC in that before ICC3 I never heard or seen any examples or manuals for ICC2 and ICC1 though again they must have existed at some point.

TX80 was that Model A14R that had a power rocker switch on the back, no scart just aerial? I had one of them years ago but scrapped it due to space constraints at the time.

Id love to find the A51F's bigger model A59F or A59N with the ICC7, but ive never even seen one of them in person only in pictures and sales brochures. I'm guessing they weren't as popular as the smaller A51F, would probably be lucky to come across any surviving examples at this stage but then again there are still ICC5's about so there's always a chance i might find one. I'm guessing ICC7 would have had as good or perhaps better sound than the ICC5.
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Old 12th Mar 2023, 4:48 pm   #97
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Default Re: Horizontal Output Transistor Question.

In Spain, I only ever saw IKC2 sets up to 21", though I still have some 24" ones in storage that could use the chassis I suppose.

The ICC7 used a horrible frame chip (TDA8177?) that often failed and became NLA; also like the ICC5 plenty of cracked solder joints that would take out the line and PSU SMPS transistors. A bit better than the ICC5 they may have been, but I disliked them.
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Old 12th Mar 2023, 5:15 pm   #98
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Default Re: Horizontal Output Transistor Question.

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
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Old 12th Mar 2023, 5:18 pm   #99
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Default Re: Horizontal Output Transistor Question.

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Similar to ICC in that before ICC3 I never heard or seen any examples or manuals for ICC2 and ICC1 though again they must have existed at some point.
ICC1 and ICC2 certainly existed on the continent, though they were quite early on so not all brands used them. Thomson themselves used them, as did Saba and Nordmende at least partially (in sets that were often regarded as still made by Saba or Nordmende, which is partially true - the chassis design might have even been a cooperation between Thomson and the still existing design departments of Saba and Nordmende). I think the ICC2 chassis was only used in projection sets.

Nordmende used their SK2 chassis name for both their own and Thomson's designs.

Last edited by Maarten; 12th Mar 2023 at 5:33 pm.
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Old 12th Mar 2023, 5:26 pm   #100
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Default Re: Horizontal Output Transistor Question.

@Maarten I have an ICC2 diagram here that is direct view, so not only projection
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