WG K7000 series blowing fuses

[neokidgeo]

Hi guys,

Doing a bit of work on my invaders shell today, I put a wg k7000 series monitor in it but the thing keeps blowing fuses on the chassis as soon as i plug it in, I got the multimeter out and measured the power just before it goes in to the chassis thats all good, tested the hot thats good, Any clues guys what it may be and if poss a way of testing


Thanks guys

Neo

[sarge]

Possible shorted C36 or flyback can lead to blown fuses if you've already checked your HOT.

[Ken Layton]

Don't forget this monitor must be operated from an isolation transformer.

[neokidgeo]

Hi guys,

Got told not to bother with the chassis as the hv unit is no longer made so got an old chassis out of storage and replaced with a new hv unit this morning, Fitted and plugged it in nice bright picture all colours were bright and clear went to make a cup of tea got back the picture was very dim to the point of there being no picture, unplugged and left it for a few hours when i plugged back in it's still the same.

Put the brightness up full on the control board but doesn't do much and put the screen control up full don't get much out of that, Is there anything that it could be other then the hv unit? the things getting me down because the bloke wants to pick it back up the weekend or i've gotta find 330 quid to give him back 

I don't get how one minute it's a nice bright screen and then the only way you can see anything is to turn all the lights out, Could it be a duff hv unit?

[SirPeale]

I don't know who told you they don't make K7000 flybacks anymore, but they do.

[neokidgeo]

Well it's a wg chassis with a zenith hv unit what i'm told 

[neokidgeo]

Could it be the 1000uf 25v cap next to it maybe?

[Ken Layton]

First of all make sure you're using isolated power to the monitor. Then I'd check for shorted components first before condemning the flyback.

[neokidgeo]

Transformer is in and working, Where would be best place to start firsted?

Cheers

[neokidgeo]

Would the b+ test point be a good place to start? My friend done it for me last time but i have no idea what and where to test it, I have a multimeter handy and me paying someone to look at it is not an option wish it was.

[Kevin Mullins]

I don't know who told you they don't make K7000 flybacks anymore, but they do.

Agreed.... someone is blowing smoke.
That is a very common monitor and flybacks are readily available.

On the second chassis:
Have you checked the chassis over real well for cold/bad solder joints ?
Worn or non functioning potentiometers?

[SirPeale]

I didn't know it was a Zenith chassis.  I think he's right about the flyback not being available anymore.

[neokidgeo]

O.k guys i've got a reading of 122 then drops to121 then goes back and forth is that normal?

[neokidgeo]

O dear i have no picture at all now this is getting me down 

[Ken Layton]

Capkit the monitor first then see what happens.

[neokidgeo]

Will order some caps tonight, Do i replace all but the filter caps?

Thanks
Neo

[Ken Layton]

The capkits will include most, but not all, capacitors needed. It will not have the large main filter capacitor (generally not needed, seldom fails), the 3 non polar caps near the video input connector, nor C51 by the 50/60 pot.

[neokidgeo]

Thanks ken will get one of them ordered