Re: 25" Amplifone - Next Step Help

Yea. 17-17.5k is with brightness pot to it's max. I can see retrace vectors
in this state. Also 17.5k is with neck socket off so that there is no
load to pull it down.

James Sweet was thinking that with the brightness turned all the way up I
have created an override of the spot killer. The high brightness has
increases G2 voltage to the point that it is ripping enough electrons off
the cathode to light the screen even though the cathodes are biased to
turn them off. He says that since the cathodes are at the same potential
when off I end up with about the same off each of them and that is why I
pretty much have all white looking vectors (with the scan circuitry
still going).

So I have HV. It's just not right. I may have to do as you suggest and
replace the resistor with a higher value to get more HV. I read about this
in the past to get the HV up to 25v to check the X-Ray protection and to
adjust HV by the book. So I understand the concept you mention.

I didn't have a chance to work on it last night since I was testing around
1/2 dozen boards in my Donkey Kong. But maybe I will get a chance to find
more tonight.

James was wanting me to get an accurate reading of the B+, G1, and G2
voltages to see what they are at. They may give some sort of indication
as to what is going on.

Thanks for the help.

Greg

On 2002.03.11 15:31 "Bachmann, Joe C" wrote:
>> Are you still only getting 17.5k?
>>
>> Try turning your brightness up first.
>>
>> Make sure you 19.5k is right. If you can't get it up to 19.5k, try a slighty
>> higher value R6, perhaps 1.5k or 2k.
>>
>> Respond back with your finds.
>>
>> JB
>>
>> -----Original Message-----
>> From: Rodger Boots [mailto:rlboots@cedar-rapids.net]
>> Sent: Monday, March 11, 2002 1:16 PM
>> To: vectorlist@synthcom.com
>> Subject: Re: VECTOR: 25" Amplifone - Next Step Help
>>
>> If it were me, I'd check the +24 and -24 supplies with the high voltage
>> running. Betcha one of those is sagging big time. If one is low I'd
>> suspect the electrolytic capacitor on the output side of the regulator.
>>
>>
>> Gregory Erway wrote:
>>>
>>> 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 Tue Mar 12 04:50:16 2002