Monstermug
Active member
Got a nice and clean Wells Gardner 15V2000 on my bench today. Well I think it's a 15V2000 anyway. It came from a Battlezone Cabaret cabinet and showed signs of retrace lines followed by blooming after about 1 hour of use.
The big giveaway here was the signs blooming which as with most vector monitors is a sign that the HV diode is going bad or not making correct contact.
I decided open the HV section and take a look. The HV diode has both legs bent over. The HV Diode is in turn held in place by two silicon boots. Inside the boots are springs which makes contact with the ends of the HV diode.
To remove the existing diode was pretty easy. Gently pull off the silicon boot on each side. If you find that it is too tight, some gentle heat with a blow dryer will soften the silicon enough for it to come free.
You might want to note down the orientation of the diode, marked with a line across one side. When putting in the new diode, make sure that line is on the same side.
The HV diode is a Varo Type 1802/1812. I believe it's the same one used in on Electrohomes b/w vector monitors.
Once replaced you can add some dielectric grease on the silicon to prevent it going brittle. Not too much as it quickly becomes messy if you do.
At the same time I thought I might as well change the filtering caps on the deflection board with 105 degree Nichs.
And decided it was time to test it. Left it on for 4 hours and picture remained perfect. A thing to note is that the image seemed more centred too as before the radar was off centred and no amounts of calibration on the pcb pots could centre it.
The big giveaway here was the signs blooming which as with most vector monitors is a sign that the HV diode is going bad or not making correct contact.
I decided open the HV section and take a look. The HV diode has both legs bent over. The HV Diode is in turn held in place by two silicon boots. Inside the boots are springs which makes contact with the ends of the HV diode.
To remove the existing diode was pretty easy. Gently pull off the silicon boot on each side. If you find that it is too tight, some gentle heat with a blow dryer will soften the silicon enough for it to come free.
You might want to note down the orientation of the diode, marked with a line across one side. When putting in the new diode, make sure that line is on the same side.
The HV diode is a Varo Type 1802/1812. I believe it's the same one used in on Electrohomes b/w vector monitors.
Once replaced you can add some dielectric grease on the silicon to prevent it going brittle. Not too much as it quickly becomes messy if you do.
At the same time I thought I might as well change the filtering caps on the deflection board with 105 degree Nichs.
And decided it was time to test it. Left it on for 4 hours and picture remained perfect. A thing to note is that the image seemed more centred too as before the radar was off centred and no amounts of calibration on the pcb pots could centre it.
