When your games go on the fritz - Suteneko's repair & mod thread.

Awesome! Every time I put an infinikey in a CPS2 I feel like I’m saving an endangered animal. I live knowing that they’ll be able to keep running for years without threat of a suicide. That reminds me. I’ve been meaning to install one in my 1944 board.


CAPCOM CPS1 A+B+C Three Wonders Repair:

The second broken PCB I picked up was a complete CAPCOM CPS1 A+B+C Stack “Three Wonders” that was listed as:

The price was £45 and my thinking was that in the worst case scenario I could at least probably do something with the B game ROM board, but it would be nice if I could get another working A or C board.

This is what I received:

It had a note attached to it stating:

I attempted to power up the A+B+C stack up but got a blank screen which was not unexpected.

So I separated all the boards so I could test them out individually.

CPS1 A motherboard PCB:

I got out my Knights of the Round B board, hooked it up to a known good de-suicided B21 C board and attached it to this 10mhz (non Dash) CPS1 A board:

It boots up with no sound and repeated background elements, but the game appears to play fine and sprites display correctly.

Since I had no sound I decided to use my logic probe on the Z80 CPU which is a common cause of loss of sound on CPS1 games and the Yamaha 2151 to check if pin activity matched what would be expected from their schematics and everything checked out okay.

Next just in case I was mistaken I decided to piggy back a known good Z80 and 2151 I had at hand:

No change…

Then I thought I hadn’t even checked the volume pot “VR1” yet. That should have been the first thing!
Straight away I noticed it was a little loose and I could spot a small crack on one of its solder joints underneath so I redid that and now I have audio:

So now I need to look into the Background repeating issues.

Looking at the A board and with a bit of help from the rather confusing schematics that have found their way online, I could isolate the possible issues to a bunch of RAM in the bottom right hand side and to the custom CAPCOM A01 PPU along with a bunch of surface mounted 74LS245.

I’ve highlighted the isolated areas below:

Since the B board covers the top of the A board it is hard to easily probe the components, so I have to resort to turning it over and probed the RAM from the bottom of the board and just reverse the pin outs.

The RAM all appears to be functioning correctly but it is impossible for me to probe the surface mounted A01 PPU and LS245’s. I attempted to power up just the A board without the ROM and security board attached to probe these but since you are missing part of the complete circuit the results won’t be reliable.

I have correct activity on all but 2 of the LS245 which have stuck high outputs, but these are also connected to ram that before had correct pin pulsing that is now also stuck high. So likely there is no issues with them but just for peace of mind I swapped them out with known working ones:

Still no joy.

This sadly leaves me with just the custom CAPCOM A01 PPU being the point of failure and I can’t get a replacement for that outside of taking one from another CPS1 A board.

For good measure I tried using the CPS1 Diagnostics ROM from Jamma Arcade:

But this really just tells me (even though some of the info is missing due to the fault) what I already knew, that the RAM was good as expected.

As a last ditch resort I re-flowed the QFP A01 PPU:

Sadly, nothing improved.

Oh well, this can become a parts board for me.


First thing to do here was to confirm if the Program ROM are good and what revision of the game this board is running. I am also little bit concerned if the data is okay on the one EPROM that has an exposed window. The ROM I need to check are 11f (RTE 30A), 12f (not marked) 11h (RTE 35A) & 12h (RTE 36A):

I dump them with my Top3000 programmer and get the following results:

RTE30A CRC: ef5b8b33
RTE31A CRC: 32835e5e
RTE35A CRC: 7d705529
RTE36A CRC: 7637975f

These match the MAME 3wonders.zip which means the data is all good on them and that I have the ETC (World) revision of the game.

Since Three Wonders is one of the CPS1 titles that has a suicide battery, I decide to write four new 27C010 EPROM with the decrypted PROG data from The Dead Battery Society and couple it with my de-suicided B21 C board:

I now try to boot it up using my CPS1 Dash A Board that came with my Street Fighter II Dash Turbo:

We have a fully working game!

CPS1 C Security PCB:

Now I could have stopped here as I had no idea if the B21 on this games C board was working or not.
I could have modified it so it would run “de-suicided” as a generic no Key B21, but I did not want to cut the traces required as instead I wanted to try and keep it original if at all possible.

I removed the battery that was dead (measuring zero volts) from the C board:

Then soldered in a brand new one:

I then decided to order an Arduino Zero and LCD shield so I could attempt to use Arcade Hacker’s CPS1 C board key injector ino script:

I removed my decrypted PROG ROM I had programmed and re-inserted the originals, but covered the exposed window on 12f’s EPROM:

I wired up the C board with Dupont cables originally as per the instructions:

However it just wasn’t working…

After testing everything with my multi-meter in connectivity mode it seems that the dupont cables were making very flaky connections so instead I decided to directly solder wires to my C board and Arduino.

Still no success… I checked online and found that a few people had issues with the C board getting insufficient power during writing so I increased my 5v up to 5.15v and finally it worked:

So I have a working Original C board and B board of “Three Wonders” now!


Spent some time today finishing up these two today. funnyplaying IPS screens, both have a new case with USB-C port so they can be run from an internal lithium battery once you plug in a truepower board from handheld legens/retrosix.


I don’t have anything as impressive to share as Suteneko, but I had a small success recently that made me happy.

I’ve been playing a ton of PSOv2 on Dreamcast lately and all of a sudden the right trigger button on an original controller stopped working. I was all set to use it as an excuse to pick up a new DC Striker controller but paused and decided to take it apart and see what was going on.

After poking around a bit, nothing really jumped out at me, so on a whim I decided to spray the contact points with this stuff:

And that’s when the magic happened. Everything is working great now. :slight_smile:

I get a lot of satisfaction keeping old things working and not adding to a landfill, so this ridiculously simple thing really made my day.


Hey, all that matters is that you got a successful repair!

I’m exactly the same and hate seeing things not being recycled, repaired and re-used, just because very few people have the skills or just can’t even be bothered now days.

I live close to my local landfill and every day see the same dodgy people who hop the security fences and scavenge stuff go past my window with bags full of stuff that it is hard to believe anyone would throw away.

One of my neighbors knows a couple of the gypsies that do that and occasionally buys stuff from them which most of the time I end up having to repair, but the upshot is I can ask him to look out for a few things for me which has paid off a couple of times.

Just going to the tip shop (which is closed due to that thing that is happening that shall not be named) horrifies me every time seeing the amount of stuff they send to landfill just because it wont turn on, they don’t have power leads or fails a stupid PAT test…

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SEGA Master System Cartridge ROM Replacement:

@anon8946355 asked on our Discord if anyone could program EPROM as:

So I started to look into this, but unfortunately perhaps as an anti piracy or more likely a price cutting measure SEGA opted to include a Memory Mapper inside the actual Mask ROM of the majority of SMS titles.

Without a Memory Mapper the SEGA Master System can only access 48KB which really isn’t enough for a lot of the games that would benefit from a Mask ROM swap to apply fixes or modifications.

However, a few titles did consistently use an external Memory Mappers and these therefore can have their Mask ROM replaced with an EPROM with capacities higher than 48K of which there are three known variants:

315-5208 - 1Mbit Maximum
315-5235 - 4Mbit Maximum with Battery Backup
315-5365 - 4Mbit Maximum

Here is an example of two different 2MBit SMS cartridges:

The one on the left (Rainbow Islands) has a MMC embedded inside the Mask Rom while the one on the right has an external 315-5235 MMC (Rastan).

If you want to read up more about this check out the Paging Chips document over at SMS Power.

Has a test I decided to try to put the SMS Power Phantasy Star re-translation 2.00 onto my original Phantasy Star cartridge:

Opening up my cartridge you can see in has an external 315-5235 MMC:

Using my De-soldering Gun I de-soldered the Mask Rom:

Mask ROM removed:

Phantasy Star uses a 4Mbit Mask Rom so I needed to find a pin compatible 4Mbit EPROM that matches the pin out below:


I choose a 27c040:

Using Lunar IPS I patch the Japanese Phantasy Star ROM (CRC:6605D36A):


Which results in a patched ROM with a CRC of A04CF71A.
I then write the patched ROM file to a 27c040 using my programmer:

Then I soldered in the 27C040:

Since this will be inside a sealed cartridge there is no need to cover the EPROM window:

Because the Phantasy Star re-translation contains FM audio I decided to test this in my MegaDrive as I don’t have a FM enabled SMS, but I do own a DBElectronics SMS convertor that includes FM Sound:

and it runs perfectly! Even my original saves load up fine:

Sadly a lot of games that would benefit from patches (such as Rainbow Island which has a glitch that crashes the game so it can not be properly completed) do not use an external MMC, so you would have to find an appropriate donor cart which is not something I like to see being done.

As for the original Phantasy Star Mask ROM, I inserted it in the ESD safe tubing that the EPROM originally came in and Blu Tacked it inside the case:


That’s awesome, I’d like to do that to my copy of Phantasy Star too… all I need is an EPROM writer :stuck_out_tongue:

edit: Is that an AMD EPROM? Cool… GPU Accelerated SMS!


Super cool! I’ve been looking into doing some stuff like this as well. In fact I’m planning to do a Gradius 3 SA-1 conversion soon following Voultar’s guide. I also have a copy of Phantasy Star for the SMS. I didn’t even know there was a re-translation for it out there. I may have to do this as well!

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Awesome work! I love that the original ROM is preserved too.

Thank you for taking an interest in this and doing the research.


I have not looked into any SMS hobby projects for a long time, but hasn’t someone created a drop in replacement PCB that would accept a standard EEPROM and donor mapper or some kind of fpga/microcontroller equivalent?

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Replacement LCD finally arrived from China. Bought this unit broken in a lot of handhelds with unspecified faults. One screen replacement and new analog stick assembly, and a good cleaning later, it’s up and running like new.


Awesome! Looks great

SEGA Master System AC Mains Adaptor (3008-05) Refurbishment:

This is not so much a log but more of an information follow up post with very little refurbishment required.

The SEGA 3008-05 AC Mains Adaptor was usually used for the Master System and Game Gear and have a much lower 500mA rating than the 1.2A you get with the Mega Drive Mains Adaptor.

Model No: 3008-05
Input: 240V 50Hz
Output: 10v DC 500mA
Polarity: Center Negative

As with the Mega Drive PSU you will need a 4mm HEX driver to open it up and again I recommend the:
Wera Kraftform Micro Series due to the small 7mm diameter holes the screws are inserted into:

There are two small clips holding it together in towards the middle of the adaptor but it open with easily with some gentle applied pressure and the internals can be simply lifted out of the housing:

Everyone of these I have opened up has had a leaking 3300μF capacitor inside of them:

This was removed:

The PCB was then cleaned up using Isopropanol:

And a new and better rated °105C 25v 3300μF capacitor was installed:

The rear of the PCB had a lot of from factory flux residue on it and some corrosion on the negative & positive terminal connectors:

Which I also cleaned up before re-assembling the adaptor:

Original 1602-05 Component List:

  • 1x 3300μF 16v °85C Capacitor
  • 4x IN4001 Diode
  • 1x 3.3KΩ Resistor

There really isn’t much that can go wrong with these, but replacing the single capacitor should at this point in time be done as a matter of maintenance.


Luigi’s Mansion 3 Store Display LED modification:

I’ve been specifically holding back on this post so I could post it on Halloween.
Hope you enjoy the seasonal theme!

Earlier this year in April I was able to save a Luigi’s Mansion 3 store promo display:

However, as a display piece I felt it was a little lacking and decided that it would look cool if I added some green back lighting to the shelves to make it look more like a creepy window opening.

So I purchased some a 5m strip of 5050 Green LED:

Luigi was removed from the front of the display:

I then carefully separated the front of the display:

Then stuck down the Green LED strips around the inside lip of the display window:

Wires were then soldered to join them all together and trailed down the inside off the display:

These LED’s are rated for 12v but as I wanted a dimmer and hopefully gloomier glow effect I dug through my spares boxed to find a 5v DC Adaptor to use so the LED’s would be at a lower intensity:




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I really should do this to all my Sega power supplies … thanks for the inspiration!

And woooow that Luigi stand, it looks amazing! Great job!


Hey, I was entertaining the idea of doing this to my copy of Phantasy Star and Ys. Where did you buy the EPROM IC from?

I just installed an FM mod into my SMS, and was disapointed to learn that those two games only have FM sound on the japanese versions.

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I’ve been sourcing my EPROM from China. I’ve yet to get any fake IC but have had a few that won’t erase fully or have stuck “FF” bytes that can’t be over written so always ordered more than I need.

Also harvested EEPROM and EPROM from junk electronics.


Nice, do you have a link to the ad for the AMD one you purchased?

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I’ve used this seller a few times:

I also seem to have better luck with AMD EPROM in general.
If you want to search for AMD EPROM just add a “AM” before the EPROM type.
So for a 27C040 search for a AM27C040 etc etc