Question about if this would be a good tube swap

arcaderookie

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Please forgive me I am new to all of this. Was thinking of doing my first tube swap. I got a hold a Toshiba 19" tube. The tube type is A48KZL90X. The horizontal reading is 3.8 and the vertical is 15.0. Was wanting to know if this would be a good tube to swap with a 19" WG7000.


Thanks in advance
 
If the neck pins are the same number (as in a lot of 19" k7000's were 8 pins and not 10) and you can swap the yokes then it will probably work.
 
If the neck pins are the same number (as in a lot of 19" k7000's were 8 pins and not 10) and you can swap the yokes then it will probably work.




What is the best way to take off the yoke? I know that you have to unscrew the hose clamp, but is their anything else holding it on. The other thing where is the best way to pull it off without getting jolted? Should I wear some kinda isolated gloves, or that's really not necessary? Just wanting to makes sure before I tackle this.

Also, is their somewhere specific to make a mark where the old yoke has been or it doesn't matter where at as long as you make a mark somewhere?


Thanks in advance
 
Some yokes are bonded to the tube and if thats the case with your donor its not going to come off all that easily. You should be able to losen that clamp on the back and firmly grab the yoke (best place is the large plastic area close to the bell of the tube) and just wiggle left and right while you pull backwards. If it starts to come off then your good to go, if not it might be bonded and your in for it.

You should reuse the magnetice rings that are with the donor tube. With a flet tip pen mark the rings position on the tube by drawing across the ring onto the glass in several spots. It will be easier for you to figure out where they go when your ready to put them back on.

As far as getting the yoke back on the new tube. If its out of square your picture will also be out of square. Trust me, you'll see what I'm talking about when you power it up. Just make sure that the pins on the top of the yoke are near 12 o'clock and you will be fine. If your careful you can twist the yoke while the monitor is powered up to get the picture straightened out.
 
I swapped out the yoke and the rings. Made sure everything was close to like it was. Turned it an nothing. Turned it off and heard a little static from it. Could I have put anything on wrong or could it be the chassis. Any help would be greatly appreciated.

Thanks in advance
 
you might need to turn the screen control up a bit. Its the white knob on the flyback closer to the board. turn it up SLOWLY until you see a pic.

The fact that you have static and no smoke is good. :)
 
I did try turning up the contrast and on the fly back. No good still black screen.

Thanks in advance
 
No I don't see a glow on the kneck. But I before I took the yoke off the donor I tried putting the chassis on it. It worked, but their was a magnifying effect off to one side of the monitor so I thought it had the wrong yoke on it. If that makes sense.

Thanks in advance
 
Hmm... So the original yoke on the donor tube showed an image but it was wrong. Now with the right yoke, no picture and no glow. You sure the monitor is still powering up?

Do you get that static sound when it powers up and when it powers down still?
 
i wonder if the other yoke stressed the chassis out and it is in HV shutdown.
what is your B+

this chassis has been rebuilt?
re-flow the chassis and the neck board.

you did connect the dag wire up after the yoke swap.
and made sure that the chassis was not grounded to the frame in any way.

A48KZL90X is a compatible tube according to the chart.

make sure you do not have a bent pin on the neck of the tube.

Peace
Buffett
 
I turned the monitor back on it sounded like it was getting voltage. But when I took my high voltage probe to the anode it wasn't showing any readings. Where is the b+ on the wg7000 chassis and I can check. And what is it suppose to read. How can I fix this problem if buffet is right that hv went into shutdown. Or is it not fixable.

Thanks in advance
 
Last edited:
this should help.

k7000bchart.png


Peace
Buffett
 
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