How to test this HV diode...??

wizard154

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Hi,

I am working on a old Midway Gunfight video monitor Motorola XM702-10.

When I short out the red wire clip going to monitor I get know snap, or spark, just nothing.

So I would like to test the HV diode used in this circuit.

It is a VARO H386C and I believe it crosses with a NTE 505.

I tried my multimeter but it shows open in both directions, is it bad or do I have to use another method to accurately test this type of diode?

http://users.zoominternet.net/~pinman/DCP_1787a.jpg

Gary
 
One direction should normally show infinity (open)

The other direction should be in the 200K Ohm range. (assuming you have your range set correctly).

If it is indeed open in both directions it needs to be replaced.

Mr. CAST
 
You can't test HV diodes with a standard DMM... they don't have enough juice to pump through them.
 
You also should not be direct shorting a B/W monitor to discharge it. That can ruin the diode.
 
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