What's new

Thrillhouse

Enthusiast
Joined
Sep 29, 2018
Messages
176
Reaction score
129
Location
STL, MO, USA
I'm looking at a Willow boardset for a local collector. The game plays fine and seems to sound fine, but has some pretty severe graphic and letter issues. Many graphics (static and moving, not sure if every component is considered a sprite) are missing layers or colors. Letters are all rendered correctly, but have the wrong colors. The game passes self tests and does show that all colors are present within the service menu. I'll attach a couple pics of the issues I'm seeing.

My troubleshooting process has been as follows:

-Reseated A, B, and C boards. No bent pins, connections feel solid.
-Verified voltages between the PSU and B board. Tested in two different jamma cabs - no difference.
-Tested with a known working A board - no change.
-Tested a known working B and C board on the Willow A board - no issues.

At this point, It's definitely something on the B or C board.

-Reseated and cleaned the pins on every socketed chip on the B board. No change.

Ideas? Perhaps a corrupt ROM?
 

Attachments

  • IMG_0600.jpg
    IMG_0600.jpg
    325.1 KB · Views: 298
  • IMG_0597.jpg
    IMG_0597.jpg
    322.5 KB · Views: 287
  • IMG_0596.jpg
    IMG_0596.jpg
    523.3 KB · Views: 281
  • Letters.JPG
    Letters.JPG
    200.6 KB · Views: 231
Dump the ROMs and compare the checksums with MAME. Very likely one or more of them is corrupt.
 
Check the custom resistor/diode arrays (DAx) near the top-left of the PCB. Sometimes they short when they die. You may notice one of the three 74LS245s is a lot hotter than usual as a result.

It is also possible your willow C board is no good. To a degree you can test with other C boards, if available.
 
I'll dump and check the roms tonight for sure.


Check the custom resistor/diode arrays (DAx) near the top-left of the PCB. Sometimes they short when they die. You may notice one of the three 74LS245s is a lot hotter than usual as a result.

It is also possible your willow C board is no good. To a degree you can test with other C boards, if available.
Will check components in the top-left as well. I haven't done a ton of research on C boards - the only other C board I have is from a Street Fighter II. Not sure if that would be reasonably compatible for testing or not.
 
My money is on the C-board, that's why @undamned 's work is so interesting...
We should be able to turn the b-21 C-board into any other C-board.
 
I just thumbed through that thread - very interesting! This is the first CPS1 board I've worked on, but I'm familiar with UD's CPS2 infinikey.
 
Willow runs with CPS-B-03 on the C board, so there are no immediate donors. Modifying the game code to run on another is not a large undertaking, or configuring a CPS-B-21 to use a custom configuration would also be possible. As it stands now, no existing CPS-B-21 combination matches CPS-B-03.
 
My money is on the C-board, that's why @undamned 's work is so interesting...
We should be able to turn the b-21 C-board into any other C-board.
This. Looking at the above images that's either A or C custom. You've confirmed the A is good, that leaves the C :(

I had 3 Final Fights and a Captain Commando recently all with similar or worse faults, all C board related.
 
Willow runs with CPS-B-03 on the C board, so there are no immediate donors. Modifying the game code to run on another is not a large undertaking, or configuring a CPS-B-21 to use a custom configuration would also be possible. As it stands now, no existing CPS-B-21 combination matches CPS-B-03.
I sent an InfiniKey CPS1 proto to Parodius to do some testing and he was able to use his battery B21 as a B03 replacement with my board.
-ud
 
Willow runs with CPS-B-03 on the C board, so there are no immediate donors. Modifying the game code to run on another is not a large undertaking, or configuring a CPS-B-21 to use a custom configuration would also be possible. As it stands now, no existing CPS-B-21 combination matches CPS-B-03.
I sent an InfiniKey CPS1 proto to Parodius to do some testing and he was able to use his battery B21 as a B03 replacement with my board.-ud
That's great news - does that mean the full meaning of the bitstream is understood, rather than being copies of existing configurations?
 
Willow runs with CPS-B-03 on the C board, so there are no immediate donors. Modifying the game code to run on another is not a large undertaking, or configuring a CPS-B-21 to use a custom configuration would also be possible. As it stands now, no existing CPS-B-21 combination matches CPS-B-03.
I sent an InfiniKey CPS1 proto to Parodius to do some testing and he was able to use his battery B21 as a B03 replacement with my board.-ud
That's great news - does that mean the full meaning of the bitstream is understood, rather than being copies of existing configurations?
Pretty much. Back when Ed had finished his B21 research, he made a youtube video that breaks it down.
-ud
 
Back
Top