Re: Wicked intermittant Amplifone (Ampliphone) issue

pj pj wrote:
> Hi All,
>
> I have an interesting one that makes you go "OH $%#&".
>
> Having been awhile , I flashed up my starwars and after a few hours of
> running normally, I glanced at the screen, and found a super bright,
> swollen, out of focus and light greenish game display, with the game
> running.
>
> Since the tube had a deflection loss sometime in the past, there
> already was a small burn spot, but now its' a lot worse (<1/4"). I
> installed a Cinelabs transformer in the past to replace a dead/red,
> which I checked almost right after I powered the game off, and found
> the ferrite core warm.
>
> Cautiously restarting the game with the screen down, I slowly brought
> the control up with a cross hatch, and it did the same behaviour
> again, with the brightness up.
>
> I'm wondering if I have a bad rectifier in the transformer, a bad
> focus/screen resistor block (connections are fine), or a tube with an
> intermittent H-K short. The 24V regulators are fine and have mil-spec
> metal power resistors replacing (as in Andre's rebuild) the regulator
> bypass ones now mounted to the main heatsink and the board was fully
> rebuilt.
Hi PJ,

You can use a filament isolation transformer to test our cathode/heater
short hypothesis...just make sure neither side of the heater is
connected to the chassis/ground.

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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