25" Amplifone - Next Step Help

From: Gregory Erway <gerway_at_redcom.com>
Date: Mon Mar 11 2002 - 08:39:15 EST

Thank you all for suggestions that have gotten me to this point. I now have
additional issues and am looking for suggestions for the next step.

Star Wars cockpit 25" Amplifone monitor is the issue. Game was received in
non-working condition. No work done on it since around 1990 and I have no
idea what was done.

WHAT I'VE DONE: (For anyone that wants to read the details)
I have a beige board but it is the smaller type similar to Blue mod board
Found R8 (HV board) leg pulled up. Reconnected it.
Checked all resistors on HV board to within 10%
Found 7924cv was missing and incorrectly installed new one (no screw insulator)
Replaced the 1n4001s.
Replaced the 7824 with a 7824cv 1.5.
Pulled BU406D and tested it fine.
Replaced Red (possibly working) with new Wintron.
Checked the brown 0 ohm jumber W1 ok (mine is white)
Installed Zanen Cap Kit. Friend did this on HV board and Deflection board for
   me as I did other work.

Tested regs with BU406D out. +26.5v -0v.
Friend noticed he put the one 1n4001 diode in backwards. Pulled and replaced.

Tested regs with BU406D out. +26.5v -32v.
Put BU406D back in and threw it in the machine.
Picture (with some of each color) was way too bright. Focus/Brightnes pots
   helped very little.
The picture was overly bright with white spot in middle. Picture was wider
   than tube and shorter than tube. You could see all the retrace vectors.
   Although there were hints of color it was mostly white.
R7 turned all the way up to increase HV but could only get to around 17k.

Replaced 7924cv again (wrong yet again) as well as 1n4001 that goes with it.
Check focus assembly for broken wires and fixed the solid white wire.
Since I messed with it I put R7 back where it was. Put focus/brightness pots
   to mechanical center.

Tested board in machine. No picture. HV only around 5k and 6.5k with R7 maxed.

Found I was an idiot with the 7924cv insulation issue.
Pulled and replaced 7924cv (correctly finally) as well as matching 1n4001 and
   10 watt 50 Ohm resistor (all I had and that was what was there anyways).
Pulled BU406D.

Tested regs with BU406D out. +26.5 -32v. (HV guide does say down to -36v ok)
Put BU406D back in.
Brightness/Focus pots back to mechanical center.
R7 to where it origionally was.
Threw it back in the machine. No picture that I can see.

Pulled Deflection board and found W3 0 Ohm jumper had leg pulled up. I didn't
   work on this board my friend did and I didn't check it. Guess he missed it.
   Also noticed that the leg pulled up had an arrow drawn on the board pointing
   to it in pen.
I also tested the other 0 Ohm brown jumpers and found W1 was dead.
I replaced W1 and W3 on Deflection board with piece of solid wire.
Threw the boards back in the game and fired it up. Still no picture.
I checked the HV and it was around 16k.
I adjusted R7 to max and got a reading of 17.5k or so (with yoke plug unplugged
   so there was no load)
Plugged yoke back in and fired it up again. Still no picture.
Adjusted focus and brightness all the way up.

NOW WHAT I HAVE:
I have a picture again. It's fairly dim. Was pretty much blue in color. Can
   see all the retrace vectors. Not really any hint of other colors. Picture
   still too wide and too short but I didn't attempt to adjust that yet. I can
   almost read "May The Force Be With You" on the Death Star but it's just a
   little too dim.

Any ideas what I should do next?

I guess there is a possibility that the Deflection Board rectifier bridge
   diodes could be blown from previous stupid moves. I don't have any on hand
   and would have to wait for an order. Any idea if I can test these with my
   DMM? I'm stupid so what setting (Diode?) and what should I expect to see
   number wise? Would bad CR16 and CR17 diodes show the signs I see with a
   HV a bit low and a picture like this?

Although I replaced W1 and W3 on the Deflection board I have not replaced the
   rest of the 0 Ohm jumpers on that board or the 1 on the HV board. I have
   tested them with continuity check however.

Can the Red Mystery Can do any of this stuff I'm seeing? If so does anyone
   have a source besides stealing it off another HV board? Anyone have one for
   sale if so?

Am I in a losing battle here? I'm learning a lot but am starting to get
   discouraged.

Greg

______________________________________________________________________________
Gregory "Awesome" Erway
(585) 924-7550 (work) gerway@redcom.com (work)
(585) 398-2672 (home) erway@rochester.rr.com (home)

           Classic Arcade Video Game Records (www.twingalaxies.com):
          Tapper World Champion - 1,263,625 6/3/01 (Tournament Rules)
      Rootbeer Tapper World Champion - 1,959,200 7/29/86 (Marathon Rules)
  M.A.C.H. 3 - Bomber Third-Place Champion - 353,200 3/22/86 (Factory Default)
  2001 Funspot/Twin Galaxies Classic Video Game World Championships 8th-place

Arcade Collection: http://www.vaps.org/members/ny/erway@rochester.rr.com.html
______________________________________________________________________________
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Received on Mon Mar 11 05:39:51 2002

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