29E31S swap tube

[ilollo360]

Hi everyone. I have got a Sanwa 29E31S monitor with a 73SX701Y22-DC23 tube. The quality is not great. Geometry is decent, but i have convergence issues on the bottom of the screen. The focus also isn't great, I even tried to adjust Focus on the flyback, but no improvement. I have a A68KJU96X from a Nanao MS 2932, can I use it with the Sanwa chassis? Thanks in advance

[grantspain]

no yoke is different

[ilollo360]

Can I swap the yokes?

[grantspain]

Can I swap the yokes?

yes but I do not know if the geometry will be good, you may need to add convergence strips
I also have a feeling there may be an issue related to the neck card/crt socket but can't be sure

[ilollo360]

I tried the Toshiba tube with the Yoke from the Sanwa, but convergence was far off. So I reinstalled the Yoke on the original tube, adjusted the convergence as best as I can, but I still have some problems. The neck board is kind of sensitive, if I press it on the neck it works, but if I don't keep it pressed the picture slowly fades to black. I also noticed that when I can see on the screen the brightness randomly changes. I tried to reflow the solder on the neck board, but no improvement. What should I do? Thanks in advance

[grantspain]

that would point towards a bad connection on the crt socket or the neck card is not fully home on the tube

[ilollo360]

Where can I find a replacement socket for the neck board?

[Sunder]

I don't think you need to get a replacement socket. maybe see if you can remove any oxidation build up on it.
Or clean the pins on the tube there. Or seating and reseating the neckboard properly on the tube there.

[ilollo360]

I desoldered the socket, I cleaned it as much as I can and then soldered it back. Now the monitor is dead. It gives me black screen, the tube charges, all I can hear is a little clicking noise under the anode cap. What could it be?

[Sunder]

LOPT problem, maybe?
Though, it's weird that that happened after you cleaned the socket.
Is there a short on the board after you reflowed it?

[ilollo360]

I checked and I found no shorts on the neck board. I don't know what could it be. The tube charges, but there is no neck glow.

[grantspain]

check the following components
r424 , c449,D402

[ilollo360]

I checked all three. They are all good. I even reflowed them, but no improvement. There is still a click under the anode cap with no picture.

[grantspain]

heater circuit ok?

[ilollo360]

How can I check it?

[ilollo360]

Hi, I got another 29E31S tube+chassis combo. This one works, but the picture after a while it has been turned on becomes too wide. I tried adjusting the Horizontal Size pot, I can get the center to fit, but top and bottom are distorted. There is also another problem. Convergence on the top left side and bottom right side is very bad. Can it be fixed with a cap kit or is the tube bad? Thanks in advance

[grantspain]

Hi, I got another 29E31S tube+chassis combo. This one works, but the picture after a while it has been turned on becomes too wide. I tried adjusting the Horizontal Size pot, I can get the center to fit, but top and bottom are distorted. There is also another problem. Convergence on the top left side and bottom right side is very bad. Can it be fixed with a cap kit or is the tube bad? Thanks in advance

horizontal size and pincushion will be flyback faulty

convergence separate issue

[ilollo360]

Ok, so you think that if I replace the flyback will it fix the Horizontal size problems? Is there something I can do to fix the convergence issues on the sides? I fixed it a little bit adjusting the convergence rings, but only on the center.

[grantspain]

yes its a well know fault on es31 chassis

I would need to see a picture after the flyback has been replaced in regards to convergence

[ilollo360]

Ok, I ordered the new flyback. I will post a picture of the monitor after I installed it. I hope it will fix my problems.