Re: WG6102 schematic

On Tue, 12 May 1998, Keith, Brendan wrote:

> Where can I find the above schematic. I have one for the 6100 or 6101
> that uses the P317, P318 and P319 boards but the 6102 uses
> P327, P328 and P329. Specifically, I think that the HV board (P329)
> is dead. Is the LED near the 555 supposed to light when it is
> operational.
> I have put my scope on the output of the 555 and there's no waveform.
> I just don't want to have my hand in there when it comes to life.
> Also, lack of HV is no reason for the spot killer LED to be on, right?
> Looks like I may have multiple problems with this monitor.
>

        The schematic should be roughly the same. Gregg Woodcock's
well-known XY FAQ explains the differences between the different monitor
boards.

        No, the LED on the HV board is not a good thing. It means that
the HV overvolt protection is kicking on. I don't know how this works
off the top of my head, but clamping the output of the 555 would
accomplish its goal of shutting down the HV section. This MAY be the
cause of your spot killer problem, becuase the HV board generates the
video B+ for the deflection amps.

Joe

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Joseph J. Welser jwelser@ccwf.cc.utexas.edu
Design Engineer -- Crystal Semiconductor Corporation
Ph.D. Student in E.E. -- University of Texas at Austin
Work: jwelser_at_crystal.cirrus.com http://www.crystal.com
P.O. Box 17847; Austin, TX 78760
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Received on Tue May 12 15:08:33 1998