K4900 help

[tevans333]

Yep. My Robotron's anode cup had been chewed on by a rat and was half gone. I pulled the clips and wire out a bit, cut it off, removed the bad cup, slid on another, reattached the clips, pulled it back into the cup - and it's been working fine...

Thanks guys, I'll give it a try this evening.

 

[tevans333]

Ok, I put on a new suction cup and re tested the chassis and still no improvement.

The picture is still expanded horizontally and squished vertically.

So far I've:
-recapped it
-resoldered the chassis including the "400" section, the white sand resistors and the vertical transistors.

Any other ideas?

 

[modessitt]

Replace the vert transistors...

 

[tevans333]

Would that also cause the horizontal issue?

 

[modessitt]

I don't see much of a horizontal issue from the angle of your pic. If the other side is off the screen, then we can adjust that with the horizontal width coil, shift jumpers, or the width cap. Let's get the vertical fixed first...

 

[modessitt]

BTW - I know you said you capped it, but a problem with C313 would also cause poor vertical deflection...

 

[tevans333]

BTW - I know you said you capped it, but a problem with C313 would also cause poor vertical deflection...

I just double checked c313, it's been replaced and is in the correct orientation with good solder joints. I'll add it to my order with the vertical transistors though in case I got a bad one.

The picture may not show it but the horizontal I way off in both directions, much more than a hwc is capable of fixing

Since I won't have parts until mid week at best I think I will test out my unknown k4600 chassis. I do have the original yoke with it still, as it is still complete on a bad tube. If I swap both the 4600 yoke and chassis with the tube from the 4900 it should work right? The tube in question is pictured at the top of the thread. My monitor knowledge is limited to only cap kits. Is this something that I should even be attempting?

 

[modessitt]

If you swap the yoke with the chassis, then yes you can swap a 4600 onto the 4900 tube...

 

[tevans333]

How difficult is it to swap yokes? Ive never done it before...

 

[modessitt]

Not hard. Do some searching here about tube swaps and yokes and you'll find all you need to know...