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Old 2nd Jan 2020, 10:31 pm   #61
julie_m
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Ugh! Get better soon.
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Old 19th Jan 2020, 5:18 pm   #62
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Hi all,
I'm back in the land of the living after illness and an unexpected trip to Poland. Phew.

I've attached some pictures of the CRT base PCB for those who are interested to see. Those resistors that might be suspect... Glyn mentioned they're 100k? I can't find them in the service manual I downloaded to see the correct ones I need to order. Do I just order 100k resistors?

Hmm

Many thanks,
Richard.
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Old 19th Jan 2020, 8:59 pm   #63
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Default Re: Samsung WS-32Z419D CRT TV green not working.

R506, R510, R511 = 100k in the schematic for the CRT board.


On your CRT board....Brown, Black, Black, Orange colour code?

Lawrence.
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Old 19th Jan 2020, 11:11 pm   #64
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Hi Lawrence,

Thank you for the reply. I fitted some new resistors but still to no effect.... Until I gave the LOPT a frustrated clout. Now the red tint has gone, all colours are back and the screen has stopped blooming. I guess the LOPT is on it's way out? Frigging thing.

Thanks everyone for replying and helping me!! I'll be on the lookout for a spare LOPT for this CRT set now.

Many thanks again,
Richard.
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Old 20th Jan 2020, 12:01 am   #65
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Unless you have just discovered a bad joint on the main board by accident? Might be worth a look

Regards
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Old 20th Jan 2020, 12:28 am   #66
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Default Re: Samsung WS-32Z419D CRT TV green not working.

If a fault responds to impact, the chances are it's caused by a poor connection somewhere. Soldered connections can crack, leaving the pin loose inside a cone of solder.

Line output stages, with large, heavy and heat-generating components soldered to the board are the perfect place for such faults to manifest, especially if the board is disposed vertically. You may as well go for broke and just resolder every pin on the flyback transformer, its driver transistor and anything else that fits the profile. If you are very unlucky, a dry joint on a LOPT can cause a nasty cascade failure by coming loose at the wrong moment and dumping all the energy in the core into an arc across the board.
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Old 20th Jan 2020, 10:43 am   #67
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Yes, resolder all the connections to anything heavy or which runs hot in that area.

I fixed my first skip-find telly (Philips CTX-E) like that and it lasted many years.
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Old 20th Jan 2020, 11:44 am   #68
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Certainly Not LOPTX,this sounds like a dry joint or at a long push noisy A1 pot on LOPTX.

Time to put on the head magnifier and sniff out those drys.
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Old 20th Jan 2020, 12:17 pm   #69
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Default Re: Samsung WS-32Z419D CRT TV green not working.

I've just finished resoldering the main board on this set. I thought I'd do the whole lot as most of the joints looked a bit iffy. I gently tapped the LOPT housing with a screwdriver handle and I do think that the pots on it could well be noisy. I made a mark for the A1 lowest pot and twiddled it left to right, turning it down brought the red tint up and all the way up I could see thin horizontal white lines. I turned the colour off via the menu then turned the pot until the red tint had gone, but getting that pot set right was a bit of a challenge. Just a tad too far and the blooming starts, and just a tad too low and the picture becomes dark with a hint of red tint. I think I've finally got it set right.
Incidentally, if the pot is noisy, how do it clean it? Do I spray in some contact cleaner or just twiddle it back and forth a few times then set it back up?

Thanks all!

Richard.
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Old 20th Jan 2020, 12:43 pm   #70
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Default Re: Samsung WS-32Z419D CRT TV green not working.

I would try contact cleaner,not WD40.
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Old 20th Jan 2020, 1:35 pm   #71
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Quote:
Originally Posted by Snarf81 View Post
Incidentally, if the pot is noisy, how do it clean it? Do I spray in some contact cleaner or just twiddle it back and forth a few times then set it back up?
Proper contact cleaner eg Servisol Super 10, and twiddling the pot back and forth to help the crud get moved away from the track. You can sometimes get away with just the latter but the job is better done using the contact cleaner first.
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Old 20th Jan 2020, 1:41 pm   #72
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Default Re: Samsung WS-32Z419D CRT TV green not working.

It is of course a pretty critical setting anyway the A1 pot.
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Old 20th Jan 2020, 2:10 pm   #73
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Default Re: Samsung WS-32Z419D CRT TV green not working.

I'd be extremely hesitant to use fluids on an A1 pot! There's quite a high voltage on it, and it might arc internally. WD40 or the usual acidic contact cleaners are out of the question. While Super 10 doesn't appear to be acidic, it's very flammable and won't evaporate too well from the closed pot housing.

If resoldering the LOPT doesn't help, maybe note the position of the A1 pot and turn it up and down a few times (with the set switched off).
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Old 20th Jan 2020, 4:15 pm   #74
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Default Re: Samsung WS-32Z419D CRT TV green not working.

I second Maarten's comment. You don't want anything in the LOPT preset housing as it's likely to make things worse. It's also very well sealed and needs to stay that way. If you do think it's the variable preset and not a dry joint, mark its position and rotate it backwards and forwards several times (power off) before returning it to its original position.

Sorry - I see Maartn's already suggested that - posts crossed.
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Old 20th Jan 2020, 6:49 pm   #75
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Be careful when re soldering joints on the LOPT. Do not sweat the joint too much when re-flowing it to the main board. Remember, there will be connections inside the LOPT to the pins which the solder will also melt whilst you are heating the pins on the board.

Giving the LOPT a clout does not indicate where the fault might be. Samsung do not have a poor reputation for manufacturing and whilst I cannot see the workmanship, these sets were manufactured using flow solder techniques and as far as I can tell, lead solder.

Poor soldered joints, otherwise known as dry joints, usually occur where the board is stressed, heated or the original part is contaminated and can often be seen as the soldered connection is either dull or unlike the surrounding ones.

Glad to note that you can once again use the TV as intended. Well done.

Chris
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Old 25th Jan 2020, 7:49 pm   #76
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Well, the flipping TV is playing up yet again. I think the LOPT is faulty as now the picture is tinted green when turned on cold and as it warms up the green tint goes and red tint comes back. Also in the middle of the screen there seems to be a sort of scratch on the inside of the screen glass. It is tinted red too and the scratch is visible when the TV is off. *Sigh*.
If this is a sign of the TV failing then I'll be stuck without a working CRT TV for all of my old vcr stuff.
Darn thing
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Old 26th Jan 2020, 3:42 pm   #77
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Default Re: Samsung WS-32Z419D CRT TV green not working.

That 'scratch' might be burn in, if it presents as a darkish spot whit the set turned off. I'm not sure if the other symptoms point exclusively to the LOPT. Could still be the tube, the socket or the tube drive.
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Old 26th Jan 2020, 4:40 pm   #78
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Ah I see. Yes that 'scratch' is there when the set is turned off. I think I've gone as far as I can with this set as I've no experience with crt tv's. I'm going to whip the back off it again tomorrow when I get help to move it and recheck the solder joints on the main pcb in case I missed some dry joints. I'm also going to spray a bit of electrical contact cleaner into the A1 pot on the lopt and work the pot back and forth a number of times just to see if the pot is indeed noisy. I'll be sure to let the cleaner dry out before I plug the set back in to see if it's made any difference. If the set goes kaput after that then I'll know not to waste anymore time with it and off to the recycling centre (or wherever takes them) it'll go. I'd never have thought that trying to get hold of a stereo crt with scart and composite sockets in my neck of the woods would be soooo difficult though.

Last edited by Snarf81; 26th Jan 2020 at 4:41 pm. Reason: Added words
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Old 26th Feb 2020, 7:42 pm   #79
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Default Re: Samsung WS-32Z419D CRT TV green not working.

Hi mods,
Can this be closed please? The TV was beyond my repair skills so it has a new home with retro gamer.

Thank you to all who've replied.

Regards
Rich.
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