Defender board problem

[ownd225]

Hey guys! I have a defender all original cab and there is a possible board issue, I think it might be the ram chip on the main pcb. What happens is when I turn the game on it makes the startup sound but comes up with a blue screen with yellow dashes from left to right on the top and bottom (I can provide pics if necessary). Thanks and I am very exited to get this up and running!

[iankellogg]

Start with the basics. Check voltages on every single board.  If you can get the eproms checked out do so. Check all the wiring and connectors.

[Player 2]

Check voltages at the power supply first, then at the CPU board.  If you don't know where to test on the CPU board I'll try to attach a picture..  Also, here's what I get on my working Defender

CPU Board Voltages
11.97
-5.22
4.74

[ownd225]

Thanks ian and p2, I will try to test everything out tonight, hopefully the boards just need a little tune up!

[ownd225]

So I was unplugging and replugging in connectors and this happened:



-boardset



-startup




-after startup


Is this a good sign?

[iankellogg]

Okay two thingies!

It looks like hsync is out of whack. that could either be from the board messing up or the monitor not being tuned properly.

It looks like the standard rug pattern of a williams game.  I would start considering messing with the cables and maybe replacing them. Search klov for williams or defender rug pattern. Should be lots of information available.

[Kevsarcade]

You +5 is way to low and this will cause problems, especially with the ram.

[HarrieD]

You +5 is way to low and this will cause problems, especially with the ram.

That +5 is from another board member, another (working) defender board.