Night Slashers PCB

[Wurstkopp]

Don't know what to do with my Night Slashers PCB. I bought it as working without sound. I received the game as stated but it would only boot normal on the second power on, on the first power on it did this:


For a while it was okay. I was able to play normal, no sprite errors or something, just a normal behaviour without the sound. Then it became worse. It startet to boot only on the third, then on the fourth power on and so on. Now everything I get from it since some weeks is a garbled screen, regardless how often I power it up.
The garbage screen is never the same, it's always a different garbage picture every time I power it up, like this for example:


The amp gets warm (not hot, but warm), also I hear some noise (the sound reacts if I turn the +5V up or down).
BTW: When everything was kinda fine in the beginning, the pcb needed at least 5,2 volts to power up.
The Koyo quartz also gets warm.

Any ideas on this? Sadly most stuff on the pcb are custom chips...

[geotrig]

I'm crap at this stuff as well ,have you pushed down on many of the chips ,it could be one of the rams or somthing failing When its working is it all ok ?
a couple of pics of the pcb might help as well

[geotrig]

http://forum.arcadeotaku.com/viewtopic.php?f=26&t=21168"

dont know if it fixed this one but something similar

[Wurstkopp]

I forgot to mention what I did so far:
- completely cleaned the pcb with soap and warm water, dried it for a week - no change at all
- of course I reseated the two eproms, took them out, cleaned the legs - no change at all
- I resoldered many of the solder joints with - no change at all

There a re only two socketed (right word?) components - the two eproms - the rest is soldered in

My tools are:
- multimeter
- logic probe

Here some pics of the pcb:

[Wurstkopp]

http://forum.arcadeotaku.com/viewtopic.php?f=26&t=21168

dont know if it fixed this one but something similar

That would be mine then, bought it from a guy from Paris on ebay...
EDIT: Ebay-name was capkit13...

[goatboy]

Think you need an expert to look at it like member Vectorglow. He did some awesome repair work for me in the past.

[Wurstkopp]

Think you need an expert to look at it like member Vectorglow. He did some awesome repair work for me in the past.

Thanksalot, I'll contact him.

[geotrig]

doh , I think i've read similar issues before and iirc peope were thinking it was something to do with load as well. well the korean looks pretty similar to the Japanese board from what i remember anyway

was that cap replaced do you know ?

+1 for vector ,he fixed my bombjack that i dont play

[Wurstkopp]

doh , I think i've read similar issues before and iirc peope were thinking it was something to do with load as well. well the korean looks pretty similar to the Japanese board from what i remember anyway

was that cap replaced do you know ?

+1 for vector ,he fixed my bombjack that i dont play

Jep, it was replaced (16V/1000mF). It looks like a pretty used one (btw on this one was a totally loose solder joint and because of it I assumed more of them on the pcb, but haven't found any).

I will replace it with a new one.
Maybe the board will instantly work again.

[Wurstkopp]

I changed the cap with no effect. The pcb is now in the hands of the mighty VectorGlow.
I'll pray every day now.

[moh]

the legs on some of the surface mounted components are looked pretty dirty, there is probably quite a few poor connections there.

[Wurstkopp]

I really hope it's just something like that.

[geotrig]

\me crosses fingers

[Wurstkopp]

.