Soft image - recap?

[Andykara2003]

Hi guys - please excuse my ignorance, I've done some research & can't quite get clear on this:

I have a number of E3000/E3001 chassis Loewe TVs that are fantastic for 15Khz. A couple of them have a soft image that's not able to be completely rectified by adjusting the focus. I'm wondering how to regain that original sharp focus of the image? Would a recapping solve this or/and are there other approaches?

Cheers...

[princess prin prin]

New flyback. New tube.

[baritonomarchetto]

A (good) pic help troubleshooting more than 100 words

[Paradroid]

If you've got a few with a couple models with the same tube types and one is sharp while the other is soft, you could switch over the chassis and see if there is an improvement. That way you can determine if it's a chassis or tube issue.

Sent from my SM-A300Y using Tapatalk

[adder]

i have 2 identical JVC tv's i use, one of them has very little use and has a sharp picture and strong scanlines, the other one has had more use; the picture is 'softer', i changed the caps in that one and it did help to make the picture less soft and the scanlines more visible, but it is still not as sharp looking as the other jvc tv (but quite close)

[Andykara2003]

i have 2 identical JVC tv's i use, one of them has very little use and has a sharp picture and strong scanlines, the other one has had more use; the picture is 'softer', i changed the caps in that one and it did help to make the picture less soft and the scanlines more visible, but it is still not as sharp looking as the other jvc tv (but quite close)

Thanks very much for that - was it hard to recap & was it fairly easy to determine and source the capacitors needed?

Paradroid - nice one -  yes, there's two E3001 Contur 2063s. Not sure I'm ready to do a full tube swap tho' - I don't have your skills!

[adder]

what i did was just change the large, and medium sized electrolytic caps, and a few smaller caps located around the large/medium caps.
i didnt change all of the caps in the jvc tv because there was such a great amount in total, so the smaller electrolytic ones i just left alone (seemed like around 20+ of small electrolytic caps).
i began by removing the back cover of my tv and inspecting the main PCB, and then with a pen and paper just wrote down all the values of the caps i wished to change. you match the capacitance numbers exactly (eg. 220uF,  1000uF, etc), but for the volts rating, you can use the same value or HIGHER. so if one of your caps you want to change is marked:  220uf  50v,  you can use a  220uf  63v,  or a 220uf 100v,  etc
i live in the UK, if you also live in the uk i recommend the only place you buy caps from is FARNELL (google search).
at the moment they are doing free postage for any size order, even just a few caps.
finally, the only capacitor brands i recommend using are:  rubycon, nichicon, panasonic, vishay.
i wouldnt bother with anything else. there's loads of garbage out there.

[adder]

i also changed a couple of caps on the neckboard for good measure

i think there is a FARNELL in usa if that's where you are based, actually farnell cover all of europe as far as i know

ps. google XC6013L and/or UA6013L for a multimeter which tests electrolytic capacitors. handy to have.

[lilshawn]

monitors have a focus adjustment on the flyback (usually the top adjustment) if you have 3 adjustments back there, it has dual focus. one will be a central focus and the other will be a perimeter focus.

give it a tweak back and forth a few times then dial it in so it's sharp in the middle (the corners are often out of focus a tiny bit anyways on single focus flybacks and tubes) and tweak the other if the corners are lousy as well.

as these flybacks age, the divider network inside the flyback that handles the focus degrades and goes out of spec.

leave the bottom adjustment (screen) you'll mess up the high voltage and your screen

[Andykara2003]

i also changed a couple of caps on the neckboard for good measure

i think there is a FARNELL in usa if that's where you are based, actually farnell cover all of europe as far as i know

ps. google XC6013L and/or UA6013L for a multimeter which tests electrolytic capacitors. handy to have.

Thanks a million Adder - I am indeed in the UK & this stuff is really helpful. When I have time I'll give this a go I think. Hopefully the lack of focus will be more down to the caps than the tube!


Lilshawn - cheers for that - I'll check but I'm pretty sure this TV's only got just the one focus control.. I tried adjusting it but even at the best setting, it wasn't that sharp....