messed up my new area 51 board

[mitch]

i'm angry

over a year and a half ago i picked up an area 51 board off ebay, right from the get go it "worked" in that it powered up and ran through the demo sequence. But it did not display on the monitor properly, nothing i tried would bring the picture anywhere close to viewable.

i just recently picked up another board hoping that the first one was faulty and not just incompatible with my monitor somehow (WG k7000 25).  So i get the new board plug it in and HOORAY it works, everything is there and i can finally play! 

just minutes ago i was in the gun calibration screen and flipped the test switch to go back into game mode, and upon switching the picture went all screwed up on me JUST LIKE MY FIRST BOARD.  something on the board it seems has also developed the annoying high pitched squeel that my first board came with.  WHAT HAPPENED? 

Upon closer investigation of the area 51 installation manual, i suspect at this point that its my power supply.  the book recommends +5 VDC @12 Amps minimum and +12 VDC @ 2 Amps.  the suppply in my cabinet is +5 @ 15 and +12 @ 5.5. I feel like a tool for not seeing that before. I think I fried something on the board, can anybody point me to what exactly it was and where i can find a replacement. thaks for any help. so angry

[grantspain]

i can't see you have fried anything,first use a multimeter to check the power supply has the correct voltages

[Doormatt]

You can't have "too many" amps from your power supply (simplification I know).

The amperage values on your PS are maximums that it's able to supply, while the values on the board are what it requires.  So, that power supply sounds correct for that board.

I still agree with grantspain though, in that you should be checking the voltages coming off the 5V and 12V rails.

[qrz]

there is nothing on the game pcb to squeel.
this is likely a monitor issue or the drive frequency is mis set

disconnecting monitor pwr will likely silence the noise .
if it does , disconnect the sync/video drive to the monitor before pwring it up again.
if it only squeels with drive applied, check dip sw settings......

ur supply can provide more current than needed - that is OK . not having enough would be a problem !

qrz

[mitch]

ok, things are good again.

i adjusted the 50/60 hz on the chassis and that brought it back, whew! I had a bit of a panic attack there when it just went haywire out of nowhere.  you were right qrz it was the monitor squeeling, that went away when i adjusted the 50/60 hz.  Good to know about the power supply too, thanks guys.  Having sorted out my new toy again i hooked up my old board that suffered from the same problem to see if i could get it working too but no such luck. For the 100th time i adjusted every pot i could and nothing seems to help.  that ones got me puzzled.  i think something must be up with that pcb, why would one display correctly and not the other when hooked up to the same cabinet on the same settings?

[SirPeale]

Because of what we techs call 'The Fuzz Factor'.

Despite the fact that the boards are the "same" there are differences in tolerances of components.  So while one board may work, the next one may require some minute adjustments.

Voltages are one thing you should ALWAYS check, no matter what, when installing boards, troubleshooting, etc.  Your +5V should be adjusted to ~5.1V.  And you'll want to examine the edge connector for corrosion, and clean that up with a Pink Pearl eraser.