Re: Tac/Scan problems

Or, believe it or not, it could be related to the power supply. I once
worked on a Star Trek that had a similar problem. I put in a different
power supply and it worked fine. Did you try hooking up the X and Y signals
to an oscilloscope and seeing if you get the same results?

Matt

----- Original Message -----
From: "Andy Welburn" <andy@andys-arcade.com>
To: <vectorlist@synthcom.com>
Sent: Friday, January 31, 2003 7:38 PM
Subject: VECTOR: Tac/Scan problems

> Hi all..
>
> We have a Tac/Scan here that we are trying to get going in time for a
> mini-meeting in the uk, .. I need some help, if anyone can be bothered :)
> I've done lots of work on 6100 and G05 stuff, but never touched a G08.
> Here's the problem:
>
> - machine worked fine for a while, game, sound, monitor, everything.
> - game started resetting, burned out +5v connector
> - connector replaced, game ran for aout 2 mins.
> - sat for 4 months in storage
> - plugged back in, +5v is 0.1v, all other voltages are ok..
> - replaced regulator (ua723) no difference.
> - gave up, took advice and wired in a pc power supply for the +5v, but
used
> original Linear supply for all other voltages.
> - The game now runs, and the monitor now runs too, but i have graphics
> glitch :
>
> here are some pics :
>
> http://www.andys-arcade.net/Dcp07427.jpg
> http://www.andys-arcade.net/Dcp07428.jpg
> http://www.andys-arcade.net/Dcp07429.jpg
>
> you can see the game running, coin it up and play it, the sound has
> knackered now tho, but that might be something unrelated, not too worried
> for now.
>
> it looks like the pcb is shunting the beam around to the correct
locations,
> but not sitting around and drawing the graphics, instead it stops and sits
> creating a spot... also, there is a nasty bright dot in the middle
anyway...
>
> has anybody seen this problem before? If i could just isolate it down to
> which pcb in the cage is bad that would help a great deal, we have a spare
> boardset, but it seems to be pretty much completely dead.
>
> My thoughts were it has to be a math problem, not a monitor problem, not a
> bad dac, or bad op-amps, has to be something before that...
>
> anyway, i'm babbling, if anyone can help, let me know thanks..
>
> Andy Welburn
> www.andys-arcade.com
>
> --------------------------------------------------------------------------
-
> ** To UNSUBSCRIBE from vectorlist, send a message with "UNSUBSCRIBE" in
the
> ** message body to vectorlist-request@synthcom.com. Please direct other
> ** questions, comments, or problems to vectorlist-owner@synthcom.com.

---------------------------------------------------------------------------
** To UNSUBSCRIBE from vectorlist, send a message with "UNSUBSCRIBE" in the
** message body to vectorlist-request@synthcom.com. Please direct other
** questions, comments, or problems to vectorlist-owner@synthcom.com.
Received on Fri Jan 31 13:04:08 2003