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Old 5th Mar 2023, 4:11 pm   #61
IKC2E51R8
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Default Re: Horizontal Output Transistor Question.

Good news so far, After your advice i changed QL07, i noticed the pad itself on one of the legs was lifting so ive repaired that and then i took the EHT and Focus cable out and re-inserted them into the LOPT

result is the set now comes on, the arcing has stopped, ive not closed it up yet to soak test it to see if it stays on without killing another HOT because there is this line on the left of the screen which i had before and solved by replacing a capacitor in the line stage i just cant remember which one, maybe someone might have seen it before and will know which one it is.

once i have that line on the screen fixed i will let it run and see if it manages to stay on, with the ludicrous amount of parts that have been changed im hoping it will.

the 'bloctches' on the screen is because i forgot to re-connect the degauss coils before starting up
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Old 5th Mar 2023, 4:32 pm   #62
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Default Re: Horizontal Output Transistor Question.

Hopefully QL07 was the root cause. I have only ever had this faulty a handful of times out of the many hundreds of these sets passed through my hands, IL14 itself is reliable I only ever had two chips that were actually faulty, replaced it anyway a fair few times to rule it out though.
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Old 5th Mar 2023, 9:14 pm   #63
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Default Re: Horizontal Output Transistor Question.

Of course old chassis will develop various non-stock faults, but statistically this is still just as likely a result of transport damage...
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Old 5th Mar 2023, 9:49 pm   #64
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Default Re: Horizontal Output Transistor Question.

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Of course old chassis will develop various non-stock faults, but statistically this is still just as likely a result of transport damage...
the board thats in this is from the 59P7 which arrived in immaculate condition and has more or less always worked perfect except for the EW fault it had when Glyn shipped it to me.

With that being said at this point its a 33 year old chassis and wasn't reliable when new so I figure im lucky ive gotten any progress on it.

Its current state is:

I tried to fix that line down the screen by changing CL41,CL44 and CL43 as i thought they were what i changed when i fixed it the last time, Nope, turn the set on and No EW, turning the pots does nothing, im gonna check and see if the supply voltage is making its way to the chip if it is then the chip is probably dead.

I've also got to resolder the pins for the front display as its not lighting and the IR sensor isn't working either which is all probably from disconnecting and reconnecting the cables so many times over the last few days
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Old 6th Mar 2023, 1:03 am   #65
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Default Re: Horizontal Output Transistor Question.

Ok so its running now on a soak test, the EW Fault was the IC died, replaced and adjusted and now EW is fine, i still have that line on the left of the screen and there's another horizontal one across the screen too a few inches from the top.

its been running for about 20 mins so far and it hasn't killed the HOT yet so that fault may be fixed but too early to tell.

Not sure where to look for the issue with the two lines on the screen.

EDIT:

It still has a problem (a new problem) it ran for half and hour then the picture blanked out, OSG and TEXT still visible but no picture just black screen, sound still works too. I turned it to standby for a about 10 mins then started it again and the picture is back so ive got an intermittent problem. Guess I gotta open it back up again and go problem hunting, any suggestions on where to start would be appreciated.
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Old 6th Mar 2023, 2:28 pm   #66
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Default Re: Horizontal Output Transistor Question.

Still have this issue, I've ruled out TV50, DL21,22 & the IF amp TDA, IL14 and ive swapped the chroma board with a known working one. OSD Works and displays perfect, as does teletext but there is nothing else on screen just blank, same on scart too, also after running for a minute or two the deflection coils start getting louder as they do if the field shift is brought down to far but this is not the case as the display remains the same.
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Old 6th Mar 2023, 8:29 pm   #67
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Default Re: Horizontal Output Transistor Question.

Ideally I would want to 'scope the sandcastle pulse at this point but as you don't have a 'scope then trace the components connected to pin 11 and 12 of IL14, pin 12 ends up ultimately sourced from pin 2 of the lopt LL53 via several components, ie. a few resistors a low value cap ( non electrolytic ) or two, and two diodes DL13,14, pin 11 of IL14 goes to BV05/20 which is the chroma board where if this pulse is incorrect can lead to blanking.

Also read up in the ICC5 circuit description about field blanking, it is possible that a faulty feedback component or a cracked track etc. is upsetting the sandcastle pulse especially with that line down the left hand side.

I mentioned CL09 100uf yesterday as this decouples the part of IL14 that is associated with QL07, noise on this line can cause some strange effects too.
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Old 6th Mar 2023, 9:18 pm   #68
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Default Re: Horizontal Output Transistor Question.

Incidentally the text chipset on this chassis produces its own sandcastle pulse to feed the chroma board and this is also used/shared with the OSG system in use here.
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Old 6th Mar 2023, 9:59 pm   #69
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Default Re: Horizontal Output Transistor Question.

Since my last post I re-installed the original chroma board and the picture came back, I'm assuming if everything is ok now that the additional parts i changed solved the no picture problem however i havnt really had it running for more than half an hour and it began as an intermittent issue.

The scan coils dont sound as stressed now (for lack of a better term) as I changed the Vertical shift pot, CF01, and CL51. I also changed CL09. The line from top to bottom is still present and slightly more visible now however its disappearing from the bottom of the screen upwards as the set warms up.

the front control LEDs are not working though and i think the cable may have been damaged from removing it so many times, sometimes it works and others it doesn't, I've re-soldered the pin connections on both boards and the result is still intermittent, im gonna take another look at the cable and see if there's any obvious damage and im gonna trace the pins on the main board to see if the connections are making their way to the next trace.

after that im happy to close it up and put it on test and see if the set stays running, the picture stays on and if that line fades out completely and in general if it behaves itself and no new fault develops.
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Old 6th Mar 2023, 10:15 pm   #70
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Default Re: Horizontal Output Transistor Question.

Good luck with it, they weren't bad sets when they were a lot younger, just let down by poor soldering from new and the EW was always a weak point.

Engineers didn't like them because they didn't understand them very well, the chassis was very compact and used early smd technology with MELF components which added to the difficulty of servicing them.

Once you know how they worked and the root causes of early failures they were a reliable chassis, certainly no worse than other sets of their time, just as the sets got older more and more faults showed up, same as any other chassis really, just being so complex and compact for their time they earned an unfair reputation imo.

I liked them and yes some faults were difficult to track down, but I thought the design was quite elegant for the time.
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Old 6th Mar 2023, 10:32 pm   #71
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Default Re: Horizontal Output Transistor Question.

Quote:
Originally Posted by IKC2E51R8 View Post
Quote:
Originally Posted by Maarten View Post
Of course old chassis will develop various non-stock faults, but statistically this is still just as likely a result of transport damage...
the board thats in this is from the 59P7 which arrived in immaculate condition and has more or less always worked perfect except for the EW fault it had when Glyn shipped it to me.
Ah, sorry, forgot about that!
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Old 6th Mar 2023, 11:26 pm   #72
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Default Re: Horizontal Output Transistor Question.

Quote:
Originally Posted by Red to black View Post
Good luck with it, they weren't bad sets when they were a lot younger, just let down by poor soldering from new and the EW was always a weak point.

Engineers didn't like them because they didn't understand them very well, the chassis was very compact and used early smd technology with MELF components which added to the difficulty of servicing them.

Once you know how they worked and the root causes of early failures they were a reliable chassis, certainly no worse than other sets of their time, just as the sets got older more and more faults showed up, same as any other chassis really, just being so complex and compact for their time they earned an unfair reputation imo.

I liked them and yes some faults were difficult to track down, but I thought the design was quite elegant for the time.
Thanks, I really do like the set and as it was a childhood model I have a soft spot for it. While this week the chassis has given me the run around in the end the power supply faults were something ive come across and solved before but for some reason it didn't click with me at the time and i allowed frustration to cloud my memory so i wasted a lot of time part swapping.

This and the IKC2 are my favourite Chassis used in Ferguson sets, I think i can safely say the IKC2 was/is far more reliable. I dont have any experience really with any Pre-Thomson Ferguson sets except my 36K3 and an E51P7 (TX98) my nan had but the only thing i remember about that set is the day it suddenly died i think i was only about 4 years old at the time. One of my neighbours also had i think an E59B5 (with extra sheet of glass over the screen) that seemed to last forever.

back to this ICC5 front controls, ive checked and the Ribbon cable is internally damaged it seems as two pins on it have no continuity, visually it looks fine but internally there must be a break so i could try mend it or the easier solution is the 59P7 can donate its ribbon cable for the time being until i have the patience to repair this one.
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Old 7th Mar 2023, 10:52 pm   #73
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Default Re: Horizontal Output Transistor Question.

well the set is staying on and the picture is staying on (so far) but the two lines on screen, the vertical one (which isn't really noticeable with content on the screen) but the horizontal one (which i havnt really talked about) definitely is and the scan coils are very loud far louder than they should be, not sure why though, any suggestions?

in this picture you can kind of make out the horizontal line but its much more noticeable in person
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Old 8th Mar 2023, 12:38 pm   #74
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Default Re: Horizontal Output Transistor Question.

Is there just the one horizontal line, and does it change its vertical position ?
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Old 8th Mar 2023, 2:09 pm   #75
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Default Re: Horizontal Output Transistor Question.

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Is there just the one horizontal line, and does it change its vertical position ?
one Horizontal line and it stays in the same position, set hasn't run for more than half an hour as the scan coil noise concerns me so i always shut it down but during the time its on the line never moves or fades, just stays static in the same place.
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Old 8th Mar 2023, 3:49 pm   #76
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Default Re: Horizontal Output Transistor Question.

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
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Old 9th Mar 2023, 9:46 pm   #77
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Default Re: Horizontal Output Transistor Question.

Check your lead dressing, with the set being dragged about so much check that you have lopt and/or scan coil leads are suitably separated from the crt drive cables etc...
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Old 9th Mar 2023, 9:52 pm   #78
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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.
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Old 9th Mar 2023, 11:48 pm   #79
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Default Re: Horizontal Output Transistor Question.

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Check your lead dressing, with the set being dragged about so much check that you have lopt and/or scan coil leads are suitably separated from the crt drive cables etc...
This was my first thought and cables are sufficiently dressed away from the neck board/other cables. In terms of the scan coil noise its happening roughly at the same time every time the set is on, after almost exactly 30 minutes each time the set has been on the noise begins, no visual disturbance happens when the noise kicks in, the coils just get three times louder than they usually are. I have a video of it that i'll upload to youtube shortly.

with the lines on the screen particularly the horizontal line across which disturbs the picture the most ive tried replacing, CL51, 52 and CP41, also CL54 and CL22, ive resoldered around the scan coil connections also and the line is still there. Has this effect been seen by anyone on this chassis before that might be able to point me in the right direction. the exact fault doesn't seem to be listed in the stock faults list.

i noticed earlier too that there is a slight high pitched whistle/whine making it through the audio circuit, (its not very loud but it is noticeable) whether audio is present in the content on screen or not yet if i mute or turn the volume down this noise disappears completely. Before the faults that began this week it never did that before.
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Old 10th Mar 2023, 12:16 am   #80
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Default Re: Horizontal Output Transistor Question.

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!

a hairdryer and freezer may help in the absence of a 'scope, but only so far!

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.

on a forum we can only go so far! and suggest things, without having the set in front of you and interpreting what we actually see we can only go so far too.
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