CP System 1.5 (Dash) – Cadillacs and Dinosaurs

 General  Comments Off on CP System 1.5 (Dash) – Cadillacs and Dinosaurs
Feb 162011

Got my first CPS Dash game today.
Its Cadillacs and Dinosaurs and has been modded so as not to suicide.

It looked like a conversion as the label is not the proper one and there is a genuine Slam Masters sticker underneath it (which I have removed and scanned) but inside all of the MASKROMs are genuine Capcom Cadillacs ones so looks like the case might be a donor.

The CPS Dash games are middle ground from the CPS1 and CPS2 boards. They have a case, it has a built in fan, Q-Sound is used and there is separate line out audio.
The boards are similar to that of CPS1 but the A board has been stripped of its audio section and this is now located on a new B board which has the Q-Sound chips and in this case, a suicide battery that when it dies it takes the sounds with it.

The C board on this is what has all the game ROM’s on it and the small D board is what is the C board on the CPS1 games. This D board also had a suicide battery on it. Phew!

No suicide mod

CPS2 A board repair log

 PCB Repair Logs, Repair Logs  Comments Off on CPS2 A board repair log
Feb 052011

Very small repair.
I have finished making up plugs for various kick harnesses which makes it nice and easy to swap out games. I started playing my Street Fighter Zero 2 game and the sound was far too loud, when I tried to enter the test mode I found that none of the buttons on the A board worked.
I opened the case and found that the buttons had seen better days.
The buttons are normal SMD push buttons. The Capcom ones have a fifth leg which is just grounding the case of the push button and the ones I have as replacement one have 3 but since the buttons are activated via plastic switches I’m not too bothered.
Id already replaced the TEST button when I took this picture.

Changed all 3 and tested the board. The volume can now be set to a normal level.

Teenage Mutant Ninja Turtles – Turtles in Time repair log #1

 PCB Repair Logs, Repair Logs  Comments Off on Teenage Mutant Ninja Turtles – Turtles in Time repair log #1
Feb 012011

Got this TMNT2 board today cheap because it had a fault of slight graphics corruption.
The intro sequence was a bit of a mess and was very responsive moved.

I ran the built in MASKROM tests and 3K and 3L came us a BAD.

As one of the ROMs was socketed I removed it tried to dump it, I got a positive match from ROMIdent. As a little test I powered the board up without the ROM in and ran the test again, this time 3K showed up as BAD (it was removed) but 3L showed as GOOD.
I then corrupted the same ROM file in MAME and ran the MAME version, I had managed to reproduce my fault.

After much probing and head scratching I found that the enable line of ROM 3K must have a break in it under the solder mask of the PCB and was quite intermittent. This line is “active low” and when it goes open circuit (or dead) the chip enables and corrupts the data being sent as both 3K and 3L are sending their data together.
I traced the line back to its source which was pin 8 of a 74ALS04 at location 18F. I have ran a link from here to pin 12 of the ROM and the board now plays perfectly and passes all tests.

Single unit black CPS2 Marvel vs Capcom

 General  Comments Off on Single unit black CPS2 Marvel vs Capcom
Jan 172011

Today I received my latest CPS2 acquisition, but in it black metal case and single board guise.
I haven’t seen too many of these black units for sale so when I did I jumped at the chance to get one.

When I inquired about this board the seller told me the suicide battery was replaced 6 months ago, when I opened up the case I find the original battery in place and the end of life date on it was 2011!
The battery cannot be replaced like the other CPS2 units, if I remove the battery as normal the board will suicide, the battery change has to be carried out with the power on. Not a massive problem but extra care needs to be taken not to short anything with the soldering iron whilst changing the battery.
Another thing to note is that should the board suicide its not a simple matter of erasing and writing new code to the EPROM’s. These boards have a SIMM with 48pin TSOP flash ROM’s fitted. I actually do have an adapter for these so its not a massive loss if I get a suicided one but I do prefer my boards to be original if possible.

I changed the battery and tested the game with no problems.

Super Street Fighter 2: The New Challengers repair log

 PCB Repair Logs, Repair Logs  Comments Off on Super Street Fighter 2: The New Challengers repair log
Nov 092010

As with the 1944 board, this came from the same seller with the same fault of a solid blue screen.

and like the 1944 board also was that the battery still had 3.6v present, the difference being was that the CPS2 suicide test EPROM didnt work with this indicating that the decryption code was still present in the memory. It is possible for the decryption code to get corrupt and with no other signs of fault I took the plunge and removed the battery, this time thought I discharged the capacitor next to the battery to make certain that the RAM with the decryption code in lost all power. The suicide test EPROM now worked.
After burning 5 new 27C4096 EPROMs for sockets 3 to 7 I fired it up and all is well again.