Re: Starwars and Amplifone Issue

PJ wrote:
> Hi All,
>
>
> After finally getting around to getting my Amplifone Star Wars up and
> running, I've got an issue that has me stumped.
>
> With the HV board being suspect, and after a good run through, I was
> awarded with the usual red-is-dead, dried out capacitors, and board
> cooked by poorly placed bypass resistors. After a complete overhaul
> consisting of replacing virtually every active device except the 555,
> recapping with revised values, installing Dale 50ohm 25W resistors on
> the heatsink, fuses in the power leads to the board and installing a
> Cinelabs transformer, I was awarded with a running HV that ran through
> the adjustment ritual without a hitch 19.5KV, shutdown works 100%, B+
> is 181v. Used the Dale resistors since they're small, stay cool, and
> mount easily to the heatsink. The newly overhauled board runs cool as
> a cucumber.
>
> While I was at it, I recapped the deflection board, and installed a
> fresh set of output and predriver transistors. All connectors have
> been cleaned, and the ground/power mods per John Robertson have been
> done. All the brown jumpers have been removed on both the HV and
> deflection boards.
>
> Now comes the problem: the vectors have issues lining up on motion
> objects, Text like the "Flight instructions to Red five" look like
> something from Bob's Honky-Tonk Country Bunker. The letters D, B and
> A amongst others have worst issues: the loops on B's are slightly too
> long, and the lower right lines on the A's are bent in toward the
> left. The Star Wars logo has issues with the top line of the S and
> the left side of the letter. Horizontal lines like the top of the
> shield indicator, insert coin, and princess leia text are crinkly, but
> are static in that they are not dancing like a bad grounds or power
> supply ripple. The level screen's mini Death Stars look like ratchet
> gears. Super bright objects like a shield level change, the closest
> green attract mode text or fireballs are so bright that the
> vectors grow out of focus, but the picture does not swell or change size.
>
> Display on a scope is 100% normal using the testpoints on the AVG and
> everything looks 100%. The board passes all self tests without an
> issue, and the brightness test screen looks ok. If I raise the X and
> Y size on the AVG to almost clipping, and lower the corresponding pots
> on the deflection board, it improves, but nowhere near where it should
> be. Shrinking the screen down displays an improvement as well.
> Aligning the BIP and linearity does not solve the text but tweaking
> the BIP will make the Starwars logo look better, at the cost of
> messing everything else up, like say the tie fighters or the trench
> vectors.
>
> On a whim, I replaced the 15V regulators and electrolytic caps on the
> AVG, since the positive one had low output. This did nothing to
> help/worsen the issue.
> Could there be an issue with the Cinelabs HV transformer or board
> causing this issue? Any other insight would be appreciated.
Misaligned vectors are usually fixed by the BIP pots on the game
motherboard - these are close to the X/Y output adjustments...but this
seems too obvious.

The other area to look at - considering that your brightness levels have
issues - is to 'scope the Z-axis output from the game PCB and follow it
on the monitor motherboard.

John :-#)#

-- 
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 
Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, VideoGames)
                 www.flippers.com 
"Old pinballers never die, they just flip out"
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