Star Wars - fully working!

[Spyridon]

Before pulling out the monitor again, I thought I would check all the voltages to make sure they are good.  Here is what I am getting:

B+     = 172
-5     = -5.19
+5     = 5.07
10.3   = 11.86
+12    = 11.78
-15    = -15.26
+15    = 14.65
-22    = -24.0
+22    = 23.79

On the two transistors on the side of the monitor cage I'm getting -23.24 and 23.11

x-out fluctuates between .05 and .1
y-out is steady at .633

Shouldn't the y-out be fluctuating?

[Level42]

I assume you have the monitor connected to the game PCB set while you measured this ?

If so, I'd expect the y to be fluctuating too.

[Spyridon]

I assume you have the monitor connected to the game PCB set while you measured this ?

If so, I'd expect the y to be fluctuating too.

I'm almost positive that the monitor was connected, but I did disconnect the monitor at one point in order to pull the boardset out far enough to get to some of the test points.  I don't think I did the for the y-out, but I will test again tonight to make sure.

[ChadTower]

Those wouldn't happen to be DC measurements, would they?  I seem to remember those lines being much higher.

[Kevin Mullins]

Test the Game Board Outputs before Turning the Monitor On.
Make sure the game board is outputting correct voltages before you power the monitor
on! Otherwise you can waste the monitor and all the above work. To test the outputs, set
your meter on DC volts and measure the leads of R600 and R700 (fuses) of the deflection
board. These are connected to the plug with wire colors yellow (R600) and orange
(R700). The correct voltage should be in the +0.5 to -0.5 volt range (basically zero volts).
The voltage will fluctuate because of changing deflection signals. If the measured voltage
is between 5 and 15 volts (positive or negative), then check the X and Y amplifiers on the
GAME board. Also check for broken potentiometers on the game board.

http://ionpool.net/arcade/tech/6100_faq.pdf

[ChadTower]

Ah, different test point.  I usually do it at the test points in the AVG section.  You don't even have to have the monitor to do that.

[Spyridon]

Ah, different test point.  I usually do it at the test points in the AVG section.  You don't even have to have the monitor to do that.

I used the test points on the AVG board.

[Kevin Mullins]

Ah, different test point.  I usually do it at the test points in the AVG section.  You don't even have to have the monitor to do that.

I used the test points on the AVG board.

I usually start there too and work my way out towards the monitor..... but it was the voltage findings portion that I really should have made note of.

The correct voltage should be in the +0.5 to -0.5 volt range (basically zero volts).
The voltage will fluctuate because of changing deflection signals. If the measured voltage
is between 5 and 15 volts (positive or negative), then check the X and Y amplifiers on the
GAME board. Also check for broken potentiometers on the game board.

And of course there will be slight variances whether the game is in "play" mode or "test" mode. Test mode will generally give more stable voltages and not fluctuate near as much.

[Spyridon]

Those wouldn't happen to be DC measurements, would they? 

My DMM has one setting for both AC and DC measurements.  The meter automatically adjusts to the correct setting.

[ChadTower]

My DMM has one setting for both AC and DC measurements.  The meter automatically adjusts to the correct setting.

Ew!  What if you want to check for AC ripple on a DC circuit?

[Level42]

Some Flukes do this too, but you can always override it. It's those pushbuttons type meters. However, I've always used the regular "dial" setting Flukes for my work because they are the easiest in every day use.

[Spyridon]

The correct voltage should be in the +0.5 to -0.5 volt range (basically zero volts).
The voltage will fluctuate because of changing deflection signals. If the measured voltage
is between 5 and 15 volts (positive or negative), then check the X and Y amplifiers on the
GAME board. Also check for broken potentiometers on the game board.

Okay, I checked again.  x-out is fluctating.  y-out is steady at 13.44.

"then check the X and Y amplifiers on the GAME board."

Where are the X and Y amplifiers and how do I check them?

[Level42]

Sorry, I forgot: can you play "blind" with this PCB set now ? I mean can you credit it and start a game and hear the sounds ?

Also, you measured the X and Y on the AVG board (the one on the PCB game-set) right ? With or without the monitor connected ?

The amplifiers on the game board are the circuits behind the DAC converters. Look up sheet 14A in the schematics drawings and you find the Y- (and X-) axis outputs. I guess it would be possible to do a bit of a compare between the X and Y axis points to see if you can find a bad IC.

Game PCB board repair can be very difficult. I struggled with my Centi board but managed to repair it. However, a SW boardset is a pretty complicated set of boards.

[Spyridon]

Sorry, I forgot: can you play "blind" with this PCB set now ? I mean can you credit it and start a game and hear the sounds ?

Game is playing blind

Also, you measured the X and Y on the AVG board (the one on the PCB game-set) right ? With or without the monitor connected ?

I measured it on the AVG board with the monitor connected

[Level42]

OK, what do the X and Y do without the monitor connected ?

[Spyridon]

OK, what do the X and Y do without the monitor connected ?

I'll check and see


This was posted over at the KLOV forums regarding my problem:

Had a smiliar problom on my sw, it was a bad vector generator chip on the video board, I changed it out and bingo spot killer off game came up! I'm pretty sure arcadechips.com has them still, I think they are about 25.00

[ChadTower]

Which is, of course, part of the AVG circuit Kevin told you to check...

[Spyridon]

Which is, of course, part of the AVG circuit Kevin told you to check...

Yes, but knowing what I need to check and knowing how to check it are two different things.  I'm kind of at a standstill here as I don't know if I can fix this myself or not.

[Spyridon]

Haven't made any progress in getting this working, so I thought I would at least get started on replacing the overlay.

Came off easier that I expected.  Just 4 screws holding it in place


The old Fire Fox overlay peeled right off with no effort


I guess I'll hang on to this.  Don't expect to ever get a Fire Fox, but this overlay could be reused if needed


Looks like the white backing on most of the overlay stayed in place.  I'll get the drill with the wire wheel attachment out and strip this right off.  After that I'll hit it with a new coat of paint before applying the new overlay.

[ChadTower]

Which is, of course, part of the AVG circuit Kevin told you to check...

Yes, but knowing what I need to check and knowing how to check it are two different things.  I'm kind of at a standstill here as I don't know if I can fix this myself or not.

Very true.  The best way I can think of on those chips is to order some spares.  Desolder the ones in there, put in some good sockets, and swap them with the new ones.  See what happens.  If you want to now you can swap the X and Y to see if the problem switches to the other one.

[Spyridon]

In order to remove the remaining parts of the Fire Fox overlay, I clamped the piece to a board to hold it in place for removal.


Using a wire wheel attachment on my drill, the white overlay remains easily came off


Next I hit it with a coat of Rustoleum satin black paint.  That will keep any rust from forming and give the new overlay a nice clean spot to adhere to.

still wet:

[ChadTower]

I was just in the shed taking pics of the finished electrical project and noticed that my Star Wars has no red in the art either.

[Spyridon]

I was just in the shed taking pics of the finished electrical project and noticed that my Star Wars has no red in the art either.

Both sides or just one?  Seems to be common to have the red faded.

[RayB]

I was just in the shed taking pics of the finished electrical project and noticed that my Star Wars has no red in the art either.

Both sides or just one?  Seems to be common to have the red faded.

I guess I'm lucky. One side is red (very slight fading), other side is pink.

[Spyridon]

Which is, of course, part of the AVG circuit Kevin told you to check...

Yes, but knowing what I need to check and knowing how to check it are two different things.  I'm kind of at a standstill here as I don't know if I can fix this myself or not.

Very true.  The best way I can think of on those chips is to order some spares.  Desolder the ones in there, put in some good sockets, and swap them with the new ones.  See what happens.  If you want to now you can swap the X and Y to see if the problem switches to the other one.

Where can I order these chips?  I looked at arcadechips.com but I'm not sure what I'm looking for.

[ChadTower]

I don't have that info on hand at the moment but it's in the manual as well as written on the chips themselves (if it hasn't worn off).  IIRC you're looking at DACs and Op Amps most likely for your issue as the likely starting point.

EDIT:  BTW, looked harder at my cab, it does have the red layer but you have to look hard for it.  So faded I hadn't seen it until I looked really closely.

[Spyridon]

I contacted Arcadechips and they do not carry the custom AVG chip.  Anyone know where I can order this from?

[RetroACTIVE]

I contacted Arcadechips and they do not carry the custom AVG chip.  Anyone know where I can order this from?

Arcadeshop?

[Kevin Mullins]

There's always something like this if he still offers them.

http://www.multigame.com/AVG.html

Have you tried swapping the X and Y parts to see if the signal problem moves to the other side?

[Spyridon]

I contacted Arcadechips and they do not carry the custom AVG chip.  Anyone know where I can order this from?

Arcadeshop?

Thanks.  Yep they have a replacement available.

[Spyridon]

Have you tried swapping the X and Y parts to see if the signal problem moves to the other side?

I haven't had a chance to do any work on this yet. 

[Spyridon]

Have you tried swapping the X and Y parts to see if the signal problem moves to the other side?

Okay, I pulled the board out to take a look at


When you say swap the X and Y parts, are you referring to the DAC chips?


Some people have said check the DAC chips, others have said swapping out the AVG chip fixed the issue with their setup.


I'm not great a soldering, so I'm not sure I want to swap those chips unless I have to.  Should I replace the AVG chip first with a new one as a starting point?

Damn, fixing the cabinets is easy.  This stuff is driving me nuts and takes the fun out of it!

[Kevin Mullins]

The quickest and easiest thing to do would be to just swap the AVG chips and see if the problem moves. (since it appears they are socketed)

[Spyridon]

The quickest and easiest thing to do would be to just swap the AVG chips and see if the problem moves. (since it appears they are socketed)

The AVG chip is socketed, but there is only 1

[Level42]

There's only 1 AVG chip, 2 DACs.

Clearly directly soldered. Not recommended to try to get them out if you're not good at soldering. You can do a compare measurement. Run the board and measure each pin on both DACs. See if there are some really off values between the same pins.

[Spyridon]

Run the board and measure each pin on both DACs. See if there are some really off values between the same pins.

1 lead on ground,  1 lead on the pin to measure?

[Level42]

Correct sir.

[ChadTower]

Get some scrap PCBs and practice your soldering.  Anyone doing PCB repair, especially at the IC level, needs to be able to do this.  Find an old VCR or something and desolder a bunch of stuff until you're comfortable with it.  Then you can desolder those chips, solder in sockets, and have the ability to swap them in and out.  If you use good sockets you won't have an issue with them failing later.

If you can get a decent AVG chip and swap it in.  That's your AVG test.

The DACs you would want to remove, socket, and swap.  If the problem follows one chip you know which is bad.  If nothing changes odds are they're both good.  Do the same with the OP Amps.

[Level42]

I'm pretty good at soldering, but my method is cutting the legs when I remove a chip. There's no way he's going to get those DACs out in one piece and not burn the tracks....

Just MHO and my experience.

[ChadTower]

I'm pretty good at soldering, but my method is cutting the legs when I remove a chip. There's no way he's going to get those DACs out in one piece and not burn the tracks....

Just MHO and my experience.

I can do it and I've only been soldering a couple of years.  Caution is definitely the priority here, though.  If he's not confident about it have someone else do it.  But there's no call for cutting out chips as debugging. 

Good use of flux, clean it off with alcohol, an iron at about 700-720, a narrow shaft screwdriver tip, and good efficient suction will get it done.