Re: Shaky Star Wars

I had a problem that I could never figure out with my star wars monitor. No
matter what I did, the picture would jiggle whenever I got hit by a tie
fighter. Then one day I hooked up the ZVG (Zektor Vector Generator) and
played star wars from my laptop while sitting in my Star Wars cockpit. The
picture was never more clear and stable. It was beautiful. The monitor was
still being powered by the same power supply. Just the X/Y signal source
was different.

For me, the problem could either be in my wiring, the connectors or perhaps
the VG on the board. I just finally realized it wasn't the monitor at all.
Right now the picture is stable enough for me, so I'm assuming it's just a
problem with my old wiring. Most likely a bad ground somewhere.

Matt

----- Original Message -----
From: "MyPearl" <mypearl@dds.nl>
To: <vectorlist@vectorlist.org>
Sent: Thursday, February 05, 2004 1:30 PM
Subject: VECTOR: Shaky Star Wars

> Waah!
>
> I've got an star Wars w/ amplifone that is driving me *mad*.
>
> The boardset is tested okay.
> The problem was with the amplifone monitor, the Y amplifier had two
toasted
> MPSU07 and MPS57 drivers (tested okay, but caused -12V offset at the
> output).
> Replacing them corrected the problem and for a day the pricture was
> brilliant and stable.
>
> Now suddenly there is a ripple in *both* the X and Youtput, causing the
> image to 'wobble' on the outsides.
>
> I can't explain it or find the cause:
>
> - Replaced filter caps on amplifone defl. board
> - Replaced the 2n2792 and 3716 pair
> - The ripple is present at the bases of the final drive stages of the amp
> board.
> - There is no ripple on the input of the differential amplifier consisting
> of TR1, TR1 and TR3 (2N2904's)
>
> Since the problem arises on both X and Y outputs, Tere should be a common
> cause, but that just leaves the rectifier, the filter caps and the
> transformer in the power supply. I tested for ground connection and also
> tried connecting a direct ground wire from the game board to the
amplifone.
> There are no dry joints on the defl. board.
>
> Anyone has any good ideas on what can cause this problem?
>
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Received on Thu Feb 5 17:54:06 2004