Re: TECH: Tempest PCB (Joel fixed it!)

Joel wins the prize!

Turns out that one of the MC1495s in the "X" section on the board was shot.
I did as Joel said though and started by swapping the TL082s out first (in
pairs) and slowly worked my way through those and into the MC1495s. I did
the "Y"s first, and the "X"s last.

Can't say THANKS enough to Joel and everyone on the list! The board is now
operational and playable.

-Steve P.

----- Original Message -----
From: "Joel Rosenzweig" <joel.rosenzweig@verizon.net>
To: <vectorlist@vectorlist.org>
Sent: Wednesday, August 04, 2004 8:19 PM
Subject: Re: VECTOR: TECH: Tempest PCB

> Steve,
>
> The single line that you see is due to lack of deflection in the opposing
> axis. If the display shows a horizontal line only, then your vertical
> deflection circuit on the Tempest board is faulty. Because Tempest is a
> portrait mode oriented game, the axis are reversed, so you'd be looking at
a
> "X" deflection circuit failure. If the display shows a vertical line
only,
> then your horizontal deflection circuit on the Tempest board is faulty.
And
> in this case, you'd be looking at the "Y" deflection circuit. On a
> landscape mode game, the "X" is horizontal and the "Y" is vertical. From
> the monitor's perspective, "X" is always horizontal and "Y" is always
> vertical, but this nomenclature is a little awkward when we rotate the
> monitor!
>
> The Tempest board has X,Y, and Z outputs. The "X" output is actually
> connected to the "Y" input on the monitor, and the "Y" output is actually
> connected to the "X" input on the monitor.
>
> The analog output section for each axis is made of a digital to analog
> converter and some op-amps. The likely scenario is that you have an
op-amp
> failure after the converter. Give thought to replacing the TL082 (op-amp)
> first. If that doesn't work, replace the MC1495. And if that doesn't
work,
> replace the AM6012 DAC.
>
> There are more elegant procedures for troubleshooting this if you have the
> right test equipment, but without it, it would be faster to just replace
> these components in the order given.
>
> Regards,
> Joel-
>
> ----- Original Message -----
> From: "Steve P." <projektzwo@yahoo.com>
> To: <vectorlist@vectorlist.org>
> Sent: Wednesday, August 04, 2004 11:26 AM
> Subject: VECTOR: TECH: Tempest PCB
>
>
> >
> > Hi everyone.
> >
> > I have 2 Tempest PCBs that I could use some assistance with. I am NOT
an
> > electronics guy, so my tech skills aren't great.
> >
> > The first one is working and playable. It has an odd habit though of
> > resetting for no appearent reason. This usually happens in the red or
> > yellow tubes. Game will be playing right along and ZAP! resets and goes
> > into attract mode. I've swapped AUX boards, reflowed solder on the
> > interconnect cable connections, swapped ROMS sd well as the other
socketed
> > chips and still get the odd reset... Any ideas?
> >
> > Board number 2 has a graphics issue. PCB coins up and plays but the
> display
> > is squished into a bent line. Checked the vector trimmer pots and they
> seem
> > ok. Also did the same swapping of parts on this PCB that I did on the
> > first. LMK if anyone would like a pic of the screen.
> >
> > Thanks in advance!
> >
> >
> >
> > -Steve P.
> >
> >
>
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>
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Received on Thu Aug 5 02:57:28 2004