Botched yoke flip (k7000)

[immortal]

I'm in dire need of assistance. I obtained a wg k7000 a few weeks ago, but just found time to work on it.

I tested out the monitor, but the video was rotated 180 degrees. After doing some reading, I thought that all I needed to do to solve my problem was a yoke flip.

The colors were Green Yellow Red Blue. Based on everything I read, I just flipped the connectors such that it was Yellow Green Red Blue.

I powered the monitor up, everything seemed okay, then I noticed that I let a little smoke out, but I can't tell from where.

I swapped the wires back and powered it up -- nothing. No glow from the tube.

Any ideas? This is heartbreaking.

[Level42]

Sounds to me you exchanged the horizontal and vertical deflection coils by doing this.  Instead you should have exchanged only Blue and Red or Green and Yellow (depending on how it was 180 degr. rotated).

Now, the vertical coil has much more resistance than the horizontal because it needs to be more powerful (needs to bend the electron bean over a longer distance then the horizontal).

So what you did was put the very small resistance on the vertical deflection circuit which expects a much higher resistance. This probably caused one of the components in the vertical deflection circuit to burn.

The horizontal deflection circuit got a much higher resistance to handle, I think it's less suspect for burning parts, but who knows..... ?

Here's some data on just some yoke, see the difference between Horizontal and Vertical:
VL: 12.70 MH
HL: 5.27 MH
VR: 11.8 Ohm
HR: 2.14 Ohm

[Kevin Mullins]

Check the chassis for bad solder joints around those pins.
You may have taken out some components.

The colors were Green Yellow Red Blue. Based on everything I read, I just flipped the connectors such that it was Yellow Green Red Blue.

Your description of what you did sounds like you did it right though since all you flipped was the Yellow/Green pair.

But if there was a bad solder joint it would be like turning the monitor on without the yoke completely plugged in, which is not good.

[immortal]

Thanks for the info. I'm fairly confident I performed the yoke swap successfully, based on all the reading I've done. I'm pretty sure I inadvertently screwed something else up.

So, as it stands, I have a nuked k7000. I'm building a cab and would *really* like to have an arcade monitor in it, but I'm having a hard time finding one.

Any tips on what I should do? Should I look for a K7000 chassis board? Should I just buy a new monitor? Should I give up?

Thanks again!

[Kevin Mullins]

A K7000 is a very common monitor and not terribly difficult to repair depending on personal knowledge and skill and willingness to learn.

[immortal]

I think I will try my hand at repairing it. It may take me years, but I'll get it. Thanks for the info.

Aside from the manual, does anyone know any other good resources for monitor repair?

[Kevin Mullins]

Aside from the manual, does anyone know any other good resources for monitor repair?

For a K7000 ?

Right here ..... 
I'm sure enough of us have worked on one of those to get ya through it.

[immortal]

This place is awesome.

In terms of determining just how much damage I've caused, any suggestions on where to start? I haven't yet broke the multimeter out, but I imagine that's the first step...