Ikari warriors pcb, character sprits missing

[Beaps]

Hi all,

I have an original snk ikari warriors pcb that is missing all the character sprites. Any idea where to start to fix this. Which chip should I probe etc

Thanks
B

[lilshawn]

i would start by removing the socketed chips one by one, cleaning the legs with a pencil eraser and then installing them back again. (pay attention to the orientation of the chip so they don't go in backwards)

[MaximRecoil]

I know this is an old thread, and you may have gotten the problem fixed by now, but low voltage can cause exactly the problem you are describing. Ikari Warriors boardsets are notoriously voltage sensitive; they generally want more than +5 volts. I would start by turning up the +5V pot on your power supply until you get a measurement of about +5.25 VDC at the board.

[namagem]

Im havin the same problem. At first, the game worked fine. Then the sprites slowly, over time, started deteriorating, along with lines encroaching on the screen. eventually the game stopped having anything on the screen besides zeros all the way down, then eventually the screen didn't have anything. Im going to try to figure out the power supply and learn the multimeter and hopefully fix this problem. Ill post my results.

[mgb]

Also do as Lil Shawn said and pull and clean all the socketed chips and reinstall.
Do one at a time so there's no confusion.

[namagem]

Ill give that a try too, I tried to look at the power supply and it was not what I expected. It wasn't clear exactly which wire was which. (-+5, 12 etc.) I did not find any place to adjust the setting of the +5.

edited..
I looked in there again and found the switching power supply. I didn't notice it at first because I traced the wire in from the wall, and the first thing it connected to, didn't look like a power supply. I took one chipset out and it didn't look too bad, but I used an eraser on the metal leads and replaced it. powered the machine back on and surprisingly it is actually playable now, the only issue being a joystick not working 100% and the screen being "dark". there is one vertical strip of bright screen on the right edge, but other than that, its dimmed, but playable.

oh yea and another issue is that the actual screen image is smaller than the area of the monitor. as if the resolution doesn't fill the potential of the screen. what could cause that?

[TKW4rr10r]

Post a few pics of what you are looking at, and someone here can definitely point you in the right direction. It may not have the same style PSU others are thinking of. Better to be on the same page before starting to mess with that PSU. I also 3rd what was stated before about the socket-ed chips ad their corresponding ports. Doesn't take much for a required cleaning.

[namagem]

I finally found the switching power supply, it was right in front of my face.   I used a basic multimeter on the leads -5 and +5 , set at 10 dcv and I believe it was reading about 15 dcv. there is one "knob" on the supply, with a H in a circle icon next to it. I tried to turn that knob but it didn't seem to want to budge. is there another way to adjust the dcv?

I just read this:  http://www.arcaderepairtips.com/2009/07/22/checking-and-replacing-a-power-supply/

and realized I didn't have the black multimeter lead on the ground of the power supply. I put black on -5, and red on +5. Ill try to do it correct tomorrow, using the knob to see if making that adjustment makes any difference to the game.  Does cleaning the socketed chips really make that much of a difference? they don't seem to be in bad shape, they are still relatively shiny.

[mgb]

When adjusting the 5 volts,
Make sure your meter leads are at the game board connector, not at the power supply.
Black lead on black (ground), red lead on +5 volt (red) and adjust knob on psu.
I always adjust to 5.1 volts.

The monitor issue sounds like it may need a good ol' cap job

[lilshawn]

you always get some voltage loss through the wires and connector. always measure it in the board. that way you know the board is getting 5 volts and not 4.7.