Jul 082023


This is my first repair log on an arcade board, i hope that my text will not be too long and useful to anyone having problems with their own PCB of the same game.

The preambule of this repair :

First thing first, i bought this PCB sold as broken with repair required, paid 130 euros.

On reception :

After pluging the board on my jamma system, i noticed that the board has at least 4 problems to fix.

The first is that i get japanese characters on screen. After reading each eproms and socketed maskroms, i see that FU-05 is from the wrong set. The solution was easy peasy : i bought a 27512 brand new on ebay, and burn the right content from the world set.

Once this first problem is fixed, i get this screen :

This error has already been solved by Porchy, this message appear when the routine that check the presence of the TC4 PAL chip fails. It indicates that the TC4 chip is wrong or toasted. And indeed, by checking with the magical finger touch, the chip is very hot.

So as a solution, i bought a replacement GAL 16V8 on ebay :

Now, the game boot correctly.

Let’s check the next problem to fix :

I see that the graphics are simply flashing constantly on the screen, it’s a mess. The culprit are the sram located here :

Those are TMM2063, and when i passed my finger on them, they were incredibly hot on touch, and the graphics were going crazy on screen. In order to confirm they are shot, i piggyback with new sram replacements bought on ebay : graphics are now fixed !

Let’s remove the buggers :

And install the brand new SRAMs :

Last problem to fix :

I noticed that jump button and start button for PL1 are not working. this board seems to have been connected backwards, so the RC1 custom components are shot. So i contacted Caius, who sold me 4 replacement RC1 pcbs, that i replaced on the board :

It was not easy to remove properly the dead RC1 components, i got 2 traces cut, that i patched after checking them with my multimeter.

Thanks to Caius on a few tips and hints here and there, the PCB is now fully working.

Another board saved ! 😀


(With many thanks to Caius for the help and the replacement parts).

Apr 142023

I’ve used this cheap desoldering station for many years now. Despite its quirks and constant demand for cleaning its been a great work horse.

The an immovable blockage happened recently and I just couldn’t clear it so decided it was time to replace the element. I thought I had a spare from years ago but turns out I have ordered the wrong part.
Looking for the correct part I found it was almost the same price to buy a new gun part itself and I wouldn’t have to mess around slicing the wired inside.

New gun came and all was well in the world for around 5 minutes when the unit got stuck in a reset loop.
Obviously there was a short somewhere so set to work checking resistance until I found a shorted element.
All the wires for this thing are very tightly routed and when i pulled them out I found this

Those small breaks in insulation from being sandwiched together so tight caused my issue. A little bit of insulation tape later and I was back in business

CalcSig – Fluke 9100 support added

 General  Comments Off on CalcSig – Fluke 9100 support added
Mar 272023

Well its been a good long while since I last did anything with this program but now in 2023 I have got around to working on it some more.
Im (hopefully) pleased to announce Fluke 9100 signature support. The catch is, my 9100 is no longer in a working state so testing has been quite limited.
No doubt there will be issues or it might just not work properly at all so any testing that anyone can do would be appreciated.

You can download it in the Software section or direct link https://www.jammarcade.net/files/Programs/calcsig.zip

 Posted by at 8:05 pm
Oct 082022

Virtvic handed over his sick Bosconian PCB at a recent event for repair. I’d not seen a Bosconian before so it was interesting to delve into one and it also gave me a chance to redump the PAL chip for the Namco version as the one we have on the PLD Archive is flagged as bad.

On power up the game went through its self test process and displays “RAM OK” and sometimes “ROM OK” then reset itself and the whole process repeats itself.
The game uses 3 x Z80’s all working together which is a little bit of a pain but luckily the MAME debugger makes this a little less painless to aid in fault finding.
In the debugger I could run through the code and see what checks are performed in what order to better narrow down where my issue was.
The memory maps for each CPU are the same apart from the ROM’s for each processor. That means all the RAM is visible to all 3 CPU’s.
CPU 1 does all the RAM tests then it lifts the /RESET pin for the other 2 CPU’s which then do a ROM test for their own ROM’s and stick the result of the ROM test into the shared main RAM.
While this is happening, CPU1 is in a loop constantly checking the RAM area for a value. When the value isnt 0x0 then it either proceeds to boot the game or flags a “ROM #” error depending on which ROM has failed.
Now around 90% of the time the “ROM OK” error didnt show before resetting and I never did see a “ROM #” error.

I pulled all the ROM’s and tested them against MAME but found this to be an undumped version. Overlaying the ROM’s on an existing set I could verify that this version booted fine so they were likely good.
All the CPU’s are socketed and all the pins were also going black so removed them to look for damage and cleaned them up in the process. On replacing the CPU’s the game booted but was very flakey. Messing with the CPU sockets I could get different behaviors so was fairly convinced at this point that the sockets were bad. In hindsight I should have suspected these earlier as they are not the best

I opted to replaced all 3 even though CPU1 socket seemed to be fine.

Next boot up went great and nothing I did would make it crash again

 Posted by at 3:46 pm
Aug 212022

Figured as I don’t do much in the way of repairs anymore I would post about any PAL news I may have.
I’ve done too much over the last couple of years to really capture here but all of the PLD files we have have now been moved to the wiki at https://www.pldarchive.co.uk so get yourself over there if you haven’t already and check it out. It covers PLD files of any sort and for any application so if you have any you are willing to share them please get in touch.

So todays news is I have successfully recreated and tested the final two missing PAL16R8 devices from Crude Buster. These were the final two that we didn’t already have so that’s a full set available now.


 Posted by at 2:51 pm