SW Amplifone question?

FlashbaxArcade

Active member
Joined
Jun 2, 2009
Messages
1,521
Reaction score
11
Location
Burleson, Texas
i have a running amp that i get squiggly lines in certain letters and especially in lower quadrant even in crosshatch test pattern! i believe it is a monitor problem and haven't replaced caps in a long time on deflection pcb either....that's my starting point!

any other ideas?

also, i dont have the black 3 prong transistor/thermistat/whatever it is that's located next to degaussing plug and have a degaussing problem!

here's a few pics:
 

Attachments

  • IMG_0124.jpg
    IMG_0124.jpg
    76.8 KB · Views: 47
  • IMG_0126.jpg
    IMG_0126.jpg
    83.8 KB · Views: 38
  • IMG_0127.jpg
    IMG_0127.jpg
    86.9 KB · Views: 42
I'd go through the amplifone FAQ for starters and do all the suggested upgrades to the deflection board and HV board. Then do all of the suggested adjustments in the manual and see what you end up with.

As for the black box by the degausing plug, it's a posistor. Without it, your monitor will not degaus. It is a PTH451 if you are looking to order a replacement. A word of caution, if you do replace it and fail to plug in the degausing plug, you will smoke the new one. Trust me, I've done it twice.
 
I've had similiar issues with squiggles on my SW. Found a cap with a cold solder joint on the AVG board. H and V pots on the deflection board can cause your issue as well.

I faintly remember something about the WG monitors having squiggles and there was a resistor you'd replace on one of the SW boards to fix it. Wonder if someone swapped that out at some time and would cause this on an AMP?
 
I have an amp in my star wars and had the exact same problem. Looks absolutely identical in fact. I replaced every electrolytic cap, the two pots and 4 heatsink transistors on the deflection board and no change. This was about 5 years ago so I only knew shotgun repair. I bought another working deflection board and the game worked like a charm (until NewYears). I never got around to revisiting the old deflection board, but I still have the board. It is tan(older version)and I never actually tested or replaced any of the small transistors like Q18-Q22 or resistors, ceramic caps, and diodes/zener diodes. I did replace all the 0 ohm jumpers. I suppose it could easily be just bad connectors. I can see looking at mine now some spotty soldering repair. Nowadays I would probably start with testing voltages coming into the board. Too bad my game is not at my place currently. My guess would be unstable voltage almost certainly caused on the deflection board.
 
As for the black box by the degausing plug, it's a posistor. Without it, your monitor will not degaus. It is a PTH451 if you are looking to order a replacement. A word of caution, if you do replace it and fail to plug in the degausing plug, you will smoke the new one. Trust me, I've done it twice.

ah, good to know! thanks, i have an extra deflection pcb to steal from
 
I've had similiar issues with squiggles on my SW. Found a cap with a cold solder joint on the AVG board. H and V pots on the deflection board can cause your issue as well.

I faintly remember something about the WG monitors having squiggles and there was a resistor you'd replace on one of the SW boards to fix it. Wonder if someone swapped that out at some time and would cause this on an AMP?

i am thinkin that the squiggly lines is caused from AVG board i would think since it is only on letters it seems in gameplay! looks like 2 squiggly problems actually...squiggly letters(especially when an "E" looks like a Greek letter) and also the lower/right squiggly lines like crosshatch!
 
i am thinkin that the squiggly lines is caused from AVG board i would think since it is only on letters it seems in gameplay! looks like 2 squiggly problems actually...squiggly letters(especially when an "E" looks like a Greek letter) and also the lower/right squiggly lines like crosshatch!

Again, exact same problem and screen looked identical to yours, not just sorta like it, especially remember E looking like sigma. Some lines drew better than others. Replaced only the deflection board and problem gone. I suppose I could be wrong, but it all points to deflection board problem. Let me know if you find out what the fix is.
 
I'll also mention in my experience TWO very common spots to have cold solder joints is R26 and R9 (the big two black or blue resistors) . Don't just reflow them. Remove old solder and flow new.
 
Again, exact same problem and screen looked identical to yours, not just sorta like it, especially remember E looking like sigma. Some lines drew better than others. Replaced only the deflection board and problem gone. I suppose I could be wrong, but it all points to deflection board problem. Let me know if you find out what the fix is.

gotcha...i will look at all on deflection pcb! i will post my fix.

thanks!
 
Fixed log!

ok, did all that was on deflection pcb, i replaced big 4700 caps, both pots, reflowed R6 and R29! still the same squiggly lines!!!

decided to fix the degaussing issue and put that posistor(sp?) back on pcb and fixed both problems, degaussing and squiggly lines!!! don't know why that black posistor has anything to do with that but it does!!!

FIX: squiggly lines was caused by no black posistor on the corner of the deflection pcb!
 
FIX: squiggly lines was caused by no black posistor on the corner of the deflection pcb!

That's odd. I've seen deflection boards work perfectly without that posistor. That's great that it fixed it, but it's inconsistant with what I've seen on a few deflection boards, as well as what I've read from other's experiences. :confused:

What color deflection board do you have? I don't think there are any differences in the boards in the area of the posistor, but now I'm curious.
 
That's odd. I've seen deflection boards work perfectly without that posistor. That's great that it fixed it, but it's inconsistant with what I've seen on a few deflection boards, as well as what I've read from other's experiences. :confused:

What color deflection board do you have? I don't think there are any differences in the boards in the area of the posistor, but now I'm curious.

its a green pcb and took posistor off of a blue deflection!

that was definitely the problem and fix cause i wanted to note any changes to every step i took and nothing changed til then!
 
Back
Top Bottom