Star Wars Amplifone - Lost Horizontal Deflection ...

kentmurphy

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Star Wars Amplifone - Lost Horizontal Deflection ...

Ok, I know what most folks are probably going to say, but I am throwing this out there anyway.

The Amplifone (or so I think) in my Star Wars is acting up again. The left side of the screen is collapsing. I pulled the deflection board to do a visual inpection and found no obvious problems. When I put it back in, the screen was fine for several hours before it collapsed again.

Questions.

Do you think this is a problem with the deflection board or something else? I realize it's hard to say, but I am looking for someone who is willing to speculate and provide troubleshooting tips.

Should I just walk through the Deflection Board Upgrade section of the Amplifone FAQ and leave it at that?

The only thing I have done to this deflection board is replace R76, but it does appear as if it's been capped in the recent past. All other mods (diode, brown jumpers) have not been done.

Kent
 
I think I'd start measuring voltages when the issue occurs -
It's an atari game - replace big blue, rebuild the ARII board, clean and rebuild the edge connector if needed. Also ad fans to keep both the HV and deflction board cool.

Those brown resistors are evil - replace them with wire for sure.
Personally I've always ordered a rebuild kit (Zanen) and just gone through the ones I had. They lasted this long - rebuilding them will probably ensure you'll never have a problem while you own it ;)
 
Well, I pulled the board again to inspect it and after putting back in, it started working again. Damn!

Kent
 
sounds like a pin inside a connector isnt making good contact.
or a cold solder joint on a header pin maybe...
 
Ok I am still fighting this problem. Originally I believed this was a cold solder joint or a problem with the harness, but I don't believe that to be the case. I can correct the deflection problem everytime when it occurs by excercising the x-size pot (R76). If I turn the pot fully clockwise, the picture will increase in size and the left size of the screen will reappear. After about a 1/2 hour or more the left side of the screen will collapse again. Very strange. I have replaced the following:

Q14
Q16
Q17
R24
R25
R76 (Twice)

I have also tested every resistor and diode in circuit and have not discovered a problem. I've got to believe this is a problem in the x deflection circuit, but I am not sure where. Has anybody else seen this issue before?

http://cid-4127ea3a33b50049.skydriv...cade/machines/starwars/images/xdeflection.jpg

Kent
 
Any update or luck in fixing this, Kent?

I am now fixing a horizontal collapse with one of my deflection boards, too. My other is repeatedly blowing F3. Both of my issues point to horizontal deflection issues, too.
 
No luck yet. To be honest, I haven't had a chance to look it again. I was hoping on a little advice from the boards. I hate like hell to shotgun something.

Kent

Any update or luck in fixing this, Kent?

I am now fixing a horizontal collapse with one of my deflection boards, too. My other is repeatedly blowing F3. Both of my issues point to horizontal deflection issues, too.
 
Any resolution to this? I'm having an issue with my Amp deflection board that sounds the same. The left side of the screen is collapsed. Works fine with another deflection board.
Board has been recapped, jumpers removed, solder reflowed, pots replaced, etc.
 

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No luck yet. To be honest, I haven't had a chance to look it again. I was hoping on a little advice from the boards. I hate like hell to shotgun something.

Kent

i dont know about everyone else, but troubleshooting monitors with old caps etc to me is an INCREDIBLE waste of time. I would rather cap it, resolder all the known problem spots, and go from there. In the case of an amplifone, i would follow the FAQ and do the upgrade. If you have the old pots on there you are wasting your time.
 
i dont know about everyone else, but troubleshooting monitors with old caps etc to me is an INCREDIBLE waste of time. I would rather cap it, resolder all the known problem spots, and go from there. In the case of an amplifone, i would follow the FAQ and do the upgrade. If you have the old pots on there you are wasting your time.

replaced the x pot twice ... the second time, I replaced the x pot and the 2 resistors it's tied to ... still no change ... unfortunately, I haven't had a chance to look at it again, because I am finishing my basement and all my games are in storage awaiting the new arcade ... I may have sometime this holiday season to revisit the problem ...
 
replaced the x pot twice ... the second time, I replaced the x pot and the 2 resistors it's tied to ... still no change ... unfortunately, I haven't had a chance to look at it again, because I am finishing my basement and all my games are in storage awaiting the new arcade ... I may have sometime this holiday season to revisit the problem ...

I've replaced the x-pot and resistors as well with no change. It's got to be something simple...I just can't find it!
 
I fixed mine today. Even though the X side transistors were metering good, I decided to replace them anyway since there wasn't much else it could be. Replaced the mpsu07, mpsu57, 3716, and 3792 on the X side and now it works great. I could have saved myself a lot of work if I would have just replaced them to begin with. Lesson learned. ;)
 
I fixed mine today. Even though the X side transistors were metering good, I decided to replace them anyway since there wasn't much else it could be. Replaced the mpsu07, mpsu57, 3716, and 3792 on the X side and now it works great. I could have saved myself a lot of work if I would have just replaced them to begin with. Lesson learned. ;)

Thanks hatrick ... this was going to be my next step ... let's hope it also works for me ...
 
Kent, are you trying the obvious? When you get the collapse, before you pull the board did you try a "wiggle" test? I had the same problem on a monitor and found that when the terminal was crimped on one of my wires, the crimper cut the wire. Most of the time, everything still touched and the monitor worked fine. I only found the problem with a wiggle test and confirmed after removing the terminals from the housing completely...
 
Thanks hatrick ... this was going to be my next step ... let's hope it also works for me ...

actually I already did this ... this problem has been lingering so long I have forgotten what components I have replaced ...
 
Kent, are you trying the obvious? When you get the collapse, before you pull the board did you try a "wiggle" test? I had the same problem on a monitor and found that when the terminal was crimped on one of my wires, the crimper cut the wire. Most of the time, everything still touched and the monitor worked fine. I only found the problem with a wiggle test and confirmed after removing the terminals from the housing completely...

I have tried wiggling a number of different components with no success ... I will try again though ...
 
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