Ghosts n Goblins Bootleg Repair Log

[Kaizen088]

I set this PCB up in the test bench this morning started to have a look at the various issues.

[tube]TOh1y00WYjA[/tube]

- Missing the Title Screen

- Lines through characters

- Random character permanently on right of screen.

- Volume goes in and out randomly

- DIP Switch 1 Bit 1 was broken

- Floating jump wires that had broken off

The game coins up and plays fine.



I resoldered the floating wires and DIP1 then started to have a look over the board.

I wanted to have a look at the character issue first.

Starting at the Character Generator ROM, all outputs were firing okay, I then looked at the two 74194s at [10D] and [11D].

Everything looked good there so next was the 74157 at [10C], the inputs were good but there was no output on pins 4 and 7.



I scrounged a replacement from a parts board and now the Title Screen is back but there is still issues with the lines through the characters.



[tube]MkBVT-63Hog[/tube]

Any suggestions?

Kaizen0882017-04-16 01:52:10

 

[Shinydaz]

Check 2114 at 11H, and 12HShinydaz2017-04-16 02:44:19

 

[Kaizen088]

Yep that was my next line of investigation, cheers.
I just picked up some new test equipment today so I'll set that up first and continue on.

I now have an old Hitachi 20Mhz V-212 Oscilloscope and a Data I/O 29A Programmer.

I also have a GQ-4X coming in the post next week..

I'm currently trying to set the PC up for the Data I/O.

I tried with Win98 and I couldn't get it to go on the first attempt so I shelved that PC and I'll give the patched XP version of Promlink 6.1 a go on another PC but I need to install XP first.

Kaizen0882017-04-16 08:24:18

 

[Kaizen088]

Check 2114 at 11H, and 12H

I spent a couple of hours on this again this afternoon and made some progress.

I followed your advice and started to look at the components surrounding the RAM .

I discovered that pin 9 on the 74175 at [14H] was floating and pin 12 was stuck low.



I replaced both Fairchild chips at [13H] and [14H], the video improved a bit more...

I kept looking around and found pins 12 and 13 on the 7404 at 9D both stuck low.



I replaced it and there are fewer lines missing from the characters...





[tube]ewTs5CjyS0M[/tube]

Kaizen0882017-04-18 15:33:26

 

[Shinydaz]

Did you try piggybacking them 2114's

 

[Kaizen088]

No not yet, I need to find a couple of spares.
I know I have a board here with some that are socketed but can remember which of the 100+ PCBs it is...

I'll have a look for them if not it's worthwile ordering some for spares anyway, I'm slowly building up inventory but it takes a while.

Edit:

Just did a Google search and realised I have a few boards with 2114's.

Gallag and DK Jr use them.

Kaizen0882017-04-27 10:42:02