WMS Dotmation Pharoah's Fortune Misc Problems

[sbmania]

I picked up a Pharoahs Fortune with a BATT error code.  Got it home and replaced the old battery with an off the board battery holder with three AA lithium batteries.  Now when powering up the Dotmation shows Williams but the slot itself is not powered up.  The -12v led is out, along with the Fault led is lit.  (Could the -12v have been out at the customers house if the BATT error message was displayed?)

I tried reseating the board several times and I get differing results.  Always the -12v led is out and the fault led is lit.  Sometimes, the leftmost 5v led is out also.  Sometimes the machine starts bonging at about 1 second intervals continuously until shut off.  A couple of times, I got an error message saying something like ROM Match(?). 

Not sure if I got a power supply problem, backplane problem, cold solders on one or both boards or what.  I don't like that everytime I reseat the boards I get different problems.  Any ideas on how to go about tracking down the problem and fixing it?  Thanks!!

[playklax01]

99% sure it's a power supply problem.  Williams machines are notorious for bad power supplies, coupled with the fact the machine is close to 30 years old, it's not surprising it's failing.  The Dotmation screen has it's own power supply which is slightly more reliable than the lower one.  You'll still get the 'Williams' splash screen when the bottom supply fails.

The other errors (bongs, Rom match, etc) are likely just incidental symptoms if the machine is getting minimal power but not enough to actually run it.  The lights on the I/O board are what to go by.  They're fluctuating now but eventually when you turn it on, it will do nothing and there will only be the 3 lights in the middle on.  That's when it's officially dead/dead. 

Original power supplies are not available anymore, but there's a tutorial posted here (sticky at the top) about how to convert a common ATX power supply to work with these machines.  I say 'common' but these are getting hard to find too...  It needs to be a hard-switched supply (not soft-switched).  If you're slightly mechanically inclined, this would be the easiest route to go. 

[sbmania]

Thanks for the reply.  I may decide to just replace the power supply as suggested.  Before that, however, I'm wondering if anyone can point me to a schematic of this lower power supply so I can take a shot at repairing it.  I'm guessing that the loss of -12v means only one or two components have failed which I might be able to replace fairly easily if I had a schematic to show me how the voltages flow. 

[Chris-socal]

There are separate voltage rails but they all share common ground. The highest failure component will be capacitors….however, when the board fails due to a shorted capacitor it often shorts a power MOSFET and/or a rectifier. The difficult part of troubleshooting comes when a component is across a coil….it will test as if it is shorted when in circuit, the only way to test those components is to take them out.
You could start by replacing the electrolytic capacitors and see if the rail comes to life.
If it isn’t blowing a fuse you have hope that its only capacitors.

Chris

[sbmania]

Inside the lower power supply, there are two boards - a top board and a lower board.  Which is likely to be the problem?  Or is it both?

[Chris-socal]

I don’t know those machines specifically, maybe there is ine PS per voltage rails. You would have to check, or look at the rating on the units.

[sbmania]

So I've had a bit of a breakthrough on Pharaoh's Fortune.  My friend at Keystone Coin Op told me that the edge connectors on both the I/O and MPU boards are prone to bad connections.  I confess that I did not 100% believe him since the gold plated pins on both of my boards are very bright and shiny and I had pulled them out and reseated them multiple times.  Even so I hit them with spray contact cleaner and scrubbed them with a toothbrush.  After reseating them a few times for good luck, I gave it a shot.

The slot came up with some kind of Ram error so I pushed the red button on the door and it switched to soft clear.  After hitting the button a few more times and turning the game on and off once or twice, the game is now playing correctly!

But there remains a fly in the ointment.  Although the game plays correctly, all sounds are correct and the game takes and pays out quarters, the -12v LED is still out.  Also the bill validator lights flash Insert Bill but the validator does not work at all.  You can hear it operating at power up.  It will take a bill, wait for a second, and then spit it back out with the rejected tone.
 After a few minutes, the validator lights then go out.  I am guessing that the validator is the only thing that needs -12v to operate?  Anyone can confirm?  If so, I'll have to try to fix that to get the validator working. 

Since I had to change the batteries, is it likely that the validator setting switched to OFF during battery change out and that is my problem?  Thanks!

[sbmania]

Here's the final update to the Pharoah's Fortune saga.  Couldn't find any components bad on the power supply that were in the -12v circuit so I checked for the voltage at the molex pin.  -12v was present!  Checked at the entrance pin to the backplane.  -12v present.  Assumed that I must have a bad trace on the backplane so I pulled it out and traced the -12v path from the molex pin all the way down to the led.  Had -12v everywhere.  LED seemed to test good but I replaced it anyway.  Now the LED is lit.  So I guess I had a bad LED the whole time??

In any case, the game works fine. I never could get the validator to accept a bill.  Sucked it in, beeped, then spit it out, no matter what bills I tried.  So I gave up and pulled it out.  The game is now solely quarter in, quarter out!  Thanks for all who chimed in with help and suggestions!