|
Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
|
Thread Tools |
5th Mar 2023, 4:11 pm | #61 |
Hexode
Join Date: Aug 2018
Location: Dublin, Republic of Ireland.
Posts: 492
|
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
__________________
Cheers, Luke |
5th Mar 2023, 4:32 pm | #62 |
Nonode
Join Date: Mar 2010
Location: Sunderland, Tyne and Wear, UK.
Posts: 2,473
|
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.
__________________
I don't suffer from Insanity. I enjoy every minute of it. |
5th Mar 2023, 9:14 pm | #63 |
Dekatron
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,184
|
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...
|
5th Mar 2023, 9:49 pm | #64 | |
Hexode
Join Date: Aug 2018
Location: Dublin, Republic of Ireland.
Posts: 492
|
Re: Horizontal Output Transistor Question.
Quote:
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
__________________
Cheers, Luke |
|
6th Mar 2023, 1:03 am | #65 |
Hexode
Join Date: Aug 2018
Location: Dublin, Republic of Ireland.
Posts: 492
|
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.
__________________
Cheers, Luke Last edited by IKC2E51R8; 6th Mar 2023 at 1:30 am. |
6th Mar 2023, 2:28 pm | #66 |
Hexode
Join Date: Aug 2018
Location: Dublin, Republic of Ireland.
Posts: 492
|
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.
__________________
Cheers, Luke |
6th Mar 2023, 8:29 pm | #67 |
Nonode
Join Date: Mar 2010
Location: Sunderland, Tyne and Wear, UK.
Posts: 2,473
|
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.
__________________
I don't suffer from Insanity. I enjoy every minute of it. Last edited by Red to black; 6th Mar 2023 at 8:37 pm. |
6th Mar 2023, 9:18 pm | #68 |
Nonode
Join Date: Mar 2010
Location: Sunderland, Tyne and Wear, UK.
Posts: 2,473
|
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.
__________________
I don't suffer from Insanity. I enjoy every minute of it. |
6th Mar 2023, 9:59 pm | #69 |
Hexode
Join Date: Aug 2018
Location: Dublin, Republic of Ireland.
Posts: 492
|
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.
__________________
Cheers, Luke |
6th Mar 2023, 10:15 pm | #70 |
Nonode
Join Date: Mar 2010
Location: Sunderland, Tyne and Wear, UK.
Posts: 2,473
|
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.
__________________
I don't suffer from Insanity. I enjoy every minute of it. |
6th Mar 2023, 10:32 pm | #71 | |
Dekatron
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,184
|
Re: Horizontal Output Transistor Question.
Quote:
|
|
6th Mar 2023, 11:26 pm | #72 | |
Hexode
Join Date: Aug 2018
Location: Dublin, Republic of Ireland.
Posts: 492
|
Re: Horizontal Output Transistor Question.
Quote:
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.
__________________
Cheers, Luke |
|
7th Mar 2023, 10:52 pm | #73 |
Hexode
Join Date: Aug 2018
Location: Dublin, Republic of Ireland.
Posts: 492
|
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
__________________
Cheers, Luke |
8th Mar 2023, 12:38 pm | #74 |
Pentode
Join Date: Jul 2020
Location: Reigate, Surrey, UK.
Posts: 130
|
Re: Horizontal Output Transistor Question.
Is there just the one horizontal line, and does it change its vertical position ?
__________________
It's alright leaving me. |
8th Mar 2023, 2:09 pm | #75 |
Hexode
Join Date: Aug 2018
Location: Dublin, Republic of Ireland.
Posts: 492
|
Re: Horizontal Output Transistor Question.
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.
__________________
Cheers, Luke |
8th Mar 2023, 3:49 pm | #76 |
Pentode
Join Date: Jul 2020
Location: Reigate, Surrey, UK.
Posts: 130
|
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
__________________
It's alright leaving me. Last edited by Amtec123; 8th Mar 2023 at 3:56 pm. |
9th Mar 2023, 9:46 pm | #77 |
Nonode
Join Date: Mar 2010
Location: Sunderland, Tyne and Wear, UK.
Posts: 2,473
|
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...
__________________
I don't suffer from Insanity. I enjoy every minute of it. |
9th Mar 2023, 9:52 pm | #78 | |
Nonode
Join Date: Mar 2010
Location: Sunderland, Tyne and Wear, UK.
Posts: 2,473
|
Re: Horizontal Output Transistor Question.
Quote:
__________________
I don't suffer from Insanity. I enjoy every minute of it. |
|
9th Mar 2023, 11:48 pm | #79 | |
Hexode
Join Date: Aug 2018
Location: Dublin, Republic of Ireland.
Posts: 492
|
Re: Horizontal Output Transistor Question.
Quote:
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.
__________________
Cheers, Luke |
|
10th Mar 2023, 12:16 am | #80 |
Nonode
Join Date: Mar 2010
Location: Sunderland, Tyne and Wear, UK.
Posts: 2,473
|
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.
__________________
I don't suffer from Insanity. I enjoy every minute of it. |