K7000 Tubeswap Questions

Phetishboy

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I have a K7000 with bad tube burn. I have a Sharp tube here with identical numbers, other than the one on the monitor ends in xxxxxxA and the one from the TV ends in xxxxxxB. I assume that though the letters are different, they will still be a perfect match. My question is on the yoke. The one on the monitor has a plastic box on top of it (which the TV tube doesn't have), and the yellow and green wires are swapped in the connectors from one yoke to the other, though the blue and red wires match. The connector is slightly different, but will still fit. Should I try the TV yoke with the tube it's on (and if I do do I need to swap the green and yellow wire) or should I just swap the yoke from the monitor tube to the TV tube?
 
You need to take some reading from the TV yoke to find out if it is compatable. You should be able to read from red to blue and green to yellow. Take resistance readings across each pair. If the numbers are close enough to the K7000 it may be a drop in replacement. I don't have access to the online charts from this computer but I believe you are looking for something in the vacinity of 2ohms and 15 ohms. Of course you have the arcade yoke there so you can just take the measurements on it as well.
 
You need to take some reading from the TV yoke to find out if it is compatable. You should be able to read from red to blue and green to yellow. Take resistance readings across each pair. If the numbers are close enough to the K7000 it may be a drop in replacement. I don't have access to the online charts from this computer but I believe you are looking for something in the vacinity of 2ohms and 15 ohms. Of course you have the arcade yoke there so you can just take the measurements on it as well.

Cool. This can be done with the yoke just sitting there unhooked?
 
Yers, unhooked and powered off. It is preferrable to check from the connector itself as opposed to the yoke. This way you can tell if there is a problem with the connector wiring.
 
I've done many K7000 tube swaps and have been very successful using the donor tube/yoke combo.

You will most likely need to swap the Yellow and Green yoke wires on the donor tube/yoke if the image is inverted.

Depending on the yoke readings, you will likely have to adjust the horizontal width coil - have monitor adjustment tools handy!

Other than that - with a recap of the chassis and a good TV tube, you should have a monitor that looks like new!

Read the sticky in the monitor forums regarding K7000 chassis and the faulty flybacks! If you have the white knobbed flyback, you should replace it!

Good luck with the tube swap!

-Muel
 
I've done many K7000 tube swaps and have been very successful using the donor tube/yoke combo.

You will most likely need to swap the Yellow and Green yoke wires on the donor tube/yoke if the image is inverted.

Depending on the yoke readings, you will likely have to adjust the horizontal width coil - have monitor adjustment tools handy!

Other than that - with a recap of the chassis and a good TV tube, you should have a monitor that looks like new!

Read the sticky in the monitor forums regarding K7000 chassis and the faulty flybacks! If you have the white knobbed flyback, you should replace it!

Good luck with the tube swap!

-Muel

It is the white knobbed flyback. Damn. No wonder it was dead when I got it. Who has the best deal the right flyback these days? Bob, Chad, other? And I tried setting my meter to ohms (I think) first 20 then 200 then back again. Got a 0 reading no matter which pins I tested. Green/Yellow, blue/red.
 
Bob has the cheapest flybacks, $20.

The 20 ohm setting should get you the info you were looking for... Are your batteries good in your meter? Does your meter display a short when the leads are put together? Do you need to shift the leads around on the meter in order to take resistance readings?
 
Bob has the cheapest flybacks, $20.

The 20 ohm setting should get you the info you were looking for... Are your batteries good in your meter? Does your meter display a short when the leads are put together? Do you need to shift the leads around on the meter in order to take resistance readings?

Yeah the battery is fine, I tested DC volts later on my DK board that were right in the 5K range. I haven't tried the leads together and I have never taken resistance readings.
 
Yeah the battery is fine, I tested DC volts later on my DK board that were right in the 5K range. I haven't tried the leads together and I have never taken resistance readings.


OK, resistance readings may require you to put the leads in different holes in the meter. I really don't know without looking at the meter. The key is to look at the meter holes and how they are marked. The black (common) lead will most likely stay in the same place. The red lead will need to be in the hole marked with an omega symbol or marked for resistance.

Once your leads are in the right location you can put your leads together and your meter should change from reading an open to reading a short. Different meters display the open differently, but you should be able to see the change to the short which is usually indicated by the meter reading very close to 0 ohms, usually under .005 ohms. As long as the meter shorts properly you are ready to test the yoke wiring.
 
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