Tech / Repair Archive

Nichibutsu Mahjong visual glitches

I’ve seen this on three different boards now, and it turns out that certain families of Nichibutsu Mahjong hardware can have problems with colour bleeding and minor visual glitches.  For example Club 90’s and The Lady Hunter

Teenage Mutant Ninja/Hero Turtles RAM fault

This one is a simple fix but I thought I’d use it to demonstrate a technique for making minor track repairs.  I received a TMHT PCB today which on testing showed this mess: While the screen is

TourVision picture problems

As discussed in other articles, the TourVision system is just a PC engine automation platform & interface.  The RGB output of PC Engine consoles is rather low, especially compared to JAMMA standards, and as such the motherboard

TourVision – busting open the BIOS data

Update 19/04/2019 – in the button codes list I had buttons I and II mixed up Update 08/05/2019 – newer version of the bios tool uploaded & corrections This is a followup to my previous article on

Mutant Night bootleg sound restoration

Mutant Night is a pretty rare game, even with it being poorly known, weird and somewhat unpopular it’s still hard to find a real one.  Thankfully bootlegs exist and some are almost perfect clones. Unfortunately there’s a

28 pin 1mbit MASK ROMs & Life Force

From time to time, you’ll come across ‘problem’ parts – like the Jaleco ROMs in my last post.  Another long standing pain in the neck are 28 pin 1mbit mask devices used primarily by Konami and Namco.

Reading HN62312 and HN62304 chips

I recently ended up buying a Jaleco Lord Of King (Astyanax) PCB, which also came with a P-47 ROM board – or maybe it was the other way around.  When I looked at it and my existing

Code archeology – Sky Smasher leads to Cabal II

I found this out a while ago, but haven’t managed to post about it yet other than mentioning it on IRC and maybe a mailing list. When I discovered Sky Smasher (which is a great shooter you

Repair – Atomic Robo-Kid encrypted CPU replacement

I bought an Atomic Robo-Kid PCB a long time ago, in fact my e-mail doesn’t even go back far enough to find out when it was.  Just one problem, it was always unreliable and over the years

Repair – Battle Garegga boot faults

I’ve had a Japanese Battle Garegga for a while, but one thing which had always bothered me is that it was fussy about which cabs it would work on and which it wouldn’t.  I found that quickly