Re: Tempest foldover on right side

Have you checked the voltage coming out of the LV2000, if it were set
too low, it could have a limiting effect like this.

-Zonn

On 12/21/2009 6:23 PM, Kevin Moore wrote:
> Yes I'm referring to the Lv2000 upgrade, I realize it's not the same
> thing. But my board set is the early version P314 and does not have
> the Protection circuit added. So I'm trying to find another cause for
> this.
>
> Kevin
>
>
> On Mon, Dec 21, 2009 at 6:35 PM, William Boucher <boucher@mnsi.net
> <mailto:boucher@mnsi.net>> wrote:
>
> Are you referring to the popular LV2000 (or similar type)
> "protection" board? This is not the same thing and doesn't
> provide the same mode of protection. The popular "/input/
> protection" board eliminates the possibility of over-stressed
> discrete transistors in the low-voltage power supply section in
> the case of a monitor with no signal applied for an extended
> period. It does this by providing proper voltage regulators
> instead of those transistors.
> The "protection" circuitry of the P327 deflection board (and
> previous versions with the very long add-on board) creates
> individual and time-sensitive current limiting circuits for the
> main output transistors. If you remove the diodes and don't
> replace them, the output current limiting mechanism will go away.
> Even if there is an LV2000 present, it won't help limit the output
> current for games that obviously overrun the limits of the screen
> frequently such as Tempest, Star Wars, Major Havoc.
> Cutting the correct diode may make the problem dissappear
> revealing root cause, but for the pennies per diode cost, I would
> certainly replace them all.
> William Boucher
>
> ----- Original Message -----
> *From:* Mark Shostak <mailto:shostakmark@gmail.com>
> *To:* vectorlist@vectorlist.org
> <mailto:vectorlist@vectorlist.org>
> *Sent:* Monday, December 21, 2009 7:19 PM
> *Subject:* Re: VECTOR: Tempest foldover on right side
>
> I was going to ask the same question, but I'd say, if you have
> a protection board, just cut the diodes out.
>
> -Mark
>
>
> On Mon, Dec 21, 2009 at 6:06 PM, William Boucher
> <boucher@mnsi.net <mailto:boucher@mnsi.net>> wrote:
>
> I may be reaching a bit here, but does your monitor have
> the built-in protection circuitry (P327 board). D807 &
> D808 are known to create some bizarre behavior
> (folding, walling, linearity issues). Just replace them
> and all of the other similar diodes in the circuit with
> new 1N4148 type. The fact that it is walling on one side
> actually points to a specific diode in the circuit but I
> don't know which one without going back through all of the
> schematics. It would be better for the long term to just
> replace them all anyway and be done with it.
> I have a discussion page dedicated to this problem here:
> http://www.biltronix.com/wg6100_germs.html
> William Boucher
>
> ----- Original Message -----
> *From:* Kevin Moore <mailto:talon.k@gmail.com>
> *To:* vectorlist@vectorlist.org
> <mailto:vectorlist@vectorlist.org>
> *Sent:* Monday, December 21, 2009 3:53 PM
> *Subject:* Re: VECTOR: Tempest foldover on right side
>
> One more interesting thing I just noticed. I increased
> the bounding box size about 1/2 more both sides for a
> total of 1 inch extra width. The fold over stays in
> the same place.
>
>
> On Mon, Dec 21, 2009 at 2:41 PM, Kevin Moore
> <talon.k@gmail.com <mailto:talon.k@gmail.com>> wrote:
>
> Been busy, but I had a chance to make a quick
> video. I taped off the region around the bounding
> box, so I would know where it was. It seems the
> problem is about 1/2 inch outside that box on the
> right side.
>
> http://www.youtube.com/watch?v=2kMXHFCB5Zk
>
>
>
>
> On Wed, Dec 16, 2009 at 7:31 AM, Andrew Welburn
> <andy@andysarcade.net
> <mailto:andy@andysarcade.net>> wrote:
>
> Don't always assume that a recently replaced
> part is 100% good, i would still replace the
> transistor with another one as a way to
> eliminate that possibility.. you just never
> know :-)
> Andrew Welburn
> www.andys-arcade.com <http://www.andys-arcade.com>
>
> ----- Original Message -----
> *From:* Kevin Moore
> <mailto:talon.k@gmail.com>
> *To:* vectorlist@vectorlist.org
> <mailto:vectorlist@vectorlist.org>
> *Sent:* Wednesday, December 16, 2009 1:18 PM
> *Subject:* Re: VECTOR: Tempest foldover on
> right side
>
> Well the rom set is V2, good point on the
> boundary limit. I don't recall off hand,
> but when I get home tonight, I'll tape off
> the bounding box on the screen, and see.
> Wouldn't think it would be the Deflection
> trans, as I replaced all the Transistors
> with new when I re-capped, and did the LV
> upgrades. Don't think I have any V3 roms
> handy, but I'll check and see if that
> makes a difference.
> Thanks for the input, gives me a few
> things to check.
> Kevin
>
>
> On Wed, Dec 16, 2009 at 2:43 AM, Andrew
> Welburn <andy@andysarcade.net
> <mailto:andy@andysarcade.net>> wrote:
>
> If its bothersome, you could try
> replacing the relevant chassis
> deflection transistor, i've seen that
> before. Tempest unfortunately will
> force the monitor to display vectors
> way, way outside the visibile screen
> area, later romsets IIRR have a fix
> for this. Even if your monitor can
> produce a full image, certain parts of
> the game will overdrive the deflection
> such that the transistors will
> partially break-down, causing other
> areas of the screen to show foldover
> like this.
> Its not clear if your boundary is
> inside or outside the real screen
> limit anyway without a photo. you
> should set the test mode pattern up to
> fill your screen then watch it in
> game, is the foldover inside this box?
> I'd replace the relevant chassis
> transistor first with a new one then
> observe... Changing the romset to a
> later revision might also help, but
> this is much more laborious, and is
> ignoring a weakness in your monitor
> anyway.
> Andrew Welburn
> www.andys-arcade.com
> <http://www.andys-arcade.com/>
>
> ----- Original Message -----
> *From:* Kevin Moore
> <mailto:talon.k@gmail.com>
> *To:* vectorlist@vectorlist.org
> <mailto:vectorlist@vectorlist.org>
> *Sent:* Tuesday, December 15, 2009
> 6:53 PM
> *Subject:* VECTOR: Tempest
> foldover on right side
>
> I've noticed that Tempest has a
> slight foldover when the player
> finishes a level, and the tube
> starts coming up. The left side
> the tube lines go infinity for
> lack of a better word, but the
> right side seems to fold over like
> hitting a wall, and it creates a
> straight line. Typically I just
> adjust the picture so that the
> monitor shroud covers this. Is
> this normal?
>
> Thanks,
>
> Kevin
>
>
>
>
>
>

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Received on Mon Dec 21 22:16:54 2009