Haunted Castle PCB that refuses to live

distropia

SouthTown StreetSweeper
10 Year Member
Joined
Apr 28, 2010
Posts
1,075
Hi folks. I'm fighting with a Haunted Castle board that is driving me nuts. When i turn it on, garbage in screen, steady not flickering. Every time you turn on is a bit different. No sound, no play.

With the logic probe, a lot of lines are bouncing, too much lines to be traced. I already did:

- Check program eproms: ok
- Check rams (not graphic ones): ok
- Check for corrosion: ok (two vias repaired)
- The custom 007327 that holds 2 rams below has been socketed and swapped with a parts board.
- Small proms C10,11,12 & 13 swapped with a parts board.
- 24mhz oscillator swapped
- now i enter in panic mode: swapped CPU and socketed, change all the IC's surrounding the cpu, pal 16L8 remove the jumper between 2 legs that comes with some boards from factory - swap by parts board...

i've desoldered and socketed 32 chips with the hope of finding a corroded trace or faulty logic but nothing.

Can this board be haunted? Can a graphic chip force the watchdog reset? can a zip graphic memory force it?

Thanks in advance for any clue
 

Xian Xi

JammaNationX,
15 Year Member
Joined
Dec 1, 2005
Posts
27,748
With video interrupts, yes, it can reset the CPU. I had that problem when using Toshiba 2018 RAM on an AES, whenever there was a video interrupt signal sent it would just reset the CPU. Changed it to Sony brand and everything worked perfectly.
 

mainman

CPS2 Person.,
20 Year Member
Joined
Mar 26, 2001
Posts
3,721
Shot gunning parts in the dark does not always work. The very first thing you need to do is check the reset line on the CPU, this will tell us a lot.

I believe this board has a custom konami CPU at position I15, i can't remember exactly but look at the schematics and probe the reset on the CPU.
 

clarkindustry

New Challenger
Joined
Sep 15, 2005
Posts
59
check the hibrid chip branded konami inside it have a vram , and pin craked from layer.
When boot up custom check vram and dont work. or do a screen message like cpu error.
 

distropia

SouthTown StreetSweeper
10 Year Member
Joined
Apr 28, 2010
Posts
1,075
Shot gunning parts in the dark does not always work. The very first thing you need to do is check the reset line on the CPU, this will tell us a lot.

I believe this board has a custom konami CPU at position I15, i can't remember exactly but look at the schematics and probe the reset on the CPU.

Ok, thanks for the tip. I'm waiting for a friend with a scope and will publish here the screenshot

check the hibrid chip branded konami inside it have a vram , and pin craked from layer.
When boot up custom check vram and dont work. or do a screen message like cpu error.

Already swapped with another identical board and same screen of garbage.
 
Top