Now that is one expensive gamble and glad your assumption was spot on!
Now that is one expensive gamble and glad your assumption was spot on!
SEGA Mega Drive AC Mains Adaptor (1602-05) Refurbishment:
Model No: 1602-05
Input: 240V 50Hz
Output: 10v DC 1.2A
Polarity: Center Negative
To open these SEGA power bricks up you will need a 4mm HEX driver.
However finding one that can open these can be quite problematic due to the depth of the holes and them only being 7mm in diameter:
I searched through quite a fair few tools before I found one that would be suitable to open these.
I recommend using a Wera Kraftform Micro Series 2069 05118120001 Nutdriver HEX 4.0 x 60mm
Now that it is opened up you need to de-solder the two points circled below:
Which separates the small PCB from the transformer leaving you with:
You can immediately see the capacitor has been leaking and that the power cable that is connected at C1 is frayed a little. This is the third SEGA mains adaptor that I have opened up and this has been the case in all of them so far.
While it is not necessary I de-solder all components from this small PCB as I intend to replace everything:
Original 1602-05 Component List:
- 1x 3300μF 16v Capacitor
- 4x 30D2 Switching Diode
- 1x 390Ω Resistor
The US 1602 AC Mains Adaptor uses slightly different components:
- 1x 3300μF 16v Capacitor
- 4x Switching Diode (unable to confirm type)
- 1x 750Ω Resistor
Here is the reverse of the PCB for anyone that is interested:
As mentioned previously it is not necessary to replace everything. The only thing you really need to replace is the single capacitor unless the other components have burnt out in which case the mains adaptor would not be working to begin with.
30D2 Switching Diodes are no longer being manufactured and are very difficult to find. These four diodes are performing the AC to DC conversion which is known as a “full-wave bridge rectifier”.
A suitable modern replacement for these are 1N5408 Switching Diodes.
For the 390Ω resistor I replaced it with a modern and more efficient 390Ω 1W Metal Oxide Resistor.
After cleaning up the PCB and slightly cutting back the frayed wire ends I re-assembled the small power PCB with the new components:
If your transformer is showing signs of rust you can also remove that by de-soldering it from the plug connectors circled below:
You can now easily use some rust removal jell on it if it is really bad or just lightly linish away the rust:
If you do this remember to replace the clear plastic piece to the bottom if it is present or just wrap it in Kapton Tape if it is not. And ensure you re-connect the polarity correctly!
I tested this power adaptor before and afterwards within my limited means and these were the results:
- DC Voltage (Unloaded): 13.30v
- DC Voltage (Mega Drive Load): 10.90v
- AMPS (Mega Drive Load): 0.8a
- DC Voltage (Unloaded): 13.40v
- DC Voltage (Mega Drive Load): 11.00v
- AMPS (Mega Drive Load): 0.8a
Not really any change for the better or worse.
It is well worth opening up your SEGA AC Mains Adaptor to change the 3300uf 16v capacitor that will be at the end of its life and sort out any frayed power cord wire ends, but everything else you can just leave alone unless there is a problem.
PS2 Slim - No Power Repair:
After doing some repairs for someone local I got given some trash consoles for free to use as spares.
One of them was a PS2 Slim that is horribly warped to the degree it looks like a vehicle had run over it at some point and was not powering up at all:
There is no way to see how badly it is damaged without opening it up.
So I opened it up, expecting to see a cracked motherboard PCB:
Well this is looking promising. The PCB is not cracked!
Could it be as simple as the power connector is damaged?
BINGO! I re-soldered the connector back to the motherboard and it lives again:
However I can not get games to load because the top of the case is too badly warped and needs to be removed to be able to use discs.
@speedlolita provided the image below which shows the two points (A+C) that need to be held down to fool the PS2 into believing the disc tray is closed:
I then successfully tested it loading both DVD and CD based games:
Sadly this PS2 Slim needs a new case but otherwise it is working perfectly again!
For now it is going into my spares box.
Bridge the switches shut and yeet the lid.
Xbox One Wired Controller Left Analog Stick Sensitivity Issue Repair:
My Xbox One controller started to have issues with its Left Analog Stick after 3000+ hours of use on PSO2, where there was a huge dead space where it could not detect anything.
You can see the dead zone highlighted in red below:
This resulted in characters in games only being able to walk slowly until you jammed the stick right to its edges which would then take several seconds before it would register and the characters in game would only then start to run.
To open up a Xbox One controller you need to carefully remove the left and right sides of the controller with a plastic pry tool:
With a T9 security screw bit remove 5 screws.
One of which is hidden underneath the serial sticker in the battery compartment:
If you peel this very carefully you will be able to stick it back down afterwards.
Carefully remove the shoulder button from its tabs so you can get easier access to the PCB and then you need to de-solder the 14 points highlighted in red below:
De-soldered and removed:
I then replaced it with a new ALPS analog stick and re-assembled after also replacing the very worn out thumb sticks :
And now working perfect again!
SEGA Master System Controller Non-Working Button “2”:
I picked up the below lot for £5GBP untested today from a dumpster diver:
I was expecting nothing to work but everything apart from Button 2 on the SMS controller was working!
Upon opening up the controller I could see there was a substantial amount of rust on the contact:
Using a fiberglass pen I lightly brushed off the rust:
Then cleaned up all the contacts with Isopropyl alcohol:
Re-assembled, cleaned and now fully working:
Let me know if you want me to post some of my older repairs and projects here!
Just wanted to say I always really enjoy these posts. I wish I was this proficient at repairing things but still really awesome to read through.
Post em all! I love repair posts!
Taito F3 Converted Game Cart Conversion:
That is a mouthful but let me explain!
When I bought my Taito F3 ( in early 2019) it came bundled with a “Puzzle Bobble 4” cart.
The picture of the listing was not very good quality and at the time I believed it was a legitimate F3 Game.
However, when it arrived you could easily tell that the labels on it were fake:
I didn’t complain or care too much because the price I paid was exceptionally low and everything worked.
Looking underneath the F3 game we can see that the Taito sticker seal has been peeled off from over the screw in the center of the cart and it is marked as: M20J0116A which is the product ID for Puzzle Bobble 2:
Upon opening the F3 cartridge up we can see that where there should be Mask Rom’s on the top and bottom rows for Graphic and sound Data that we have EPROM’s with uncovered windows:
Upon turning over the PCB you can see all the flux residue that was not cleaned up and the poor soldering by whoever converted this F3 game originally:
Has I was not happy owning a bootleg/conversion, I eventually bought the original Puzzle Bobble 2-4:
So now I had a conversion I no longer required, I decided I would do something special with it and convert it into a game I could not realistically afford and really wanted to play on original hardware and do a good job of it.
For Taito F3 conversions you have to pay very special heed to what PAL you have at position IC21:
This will either be a D77-14 or a D77-15.
D77-14 is used for Program EPROM’s that are 27c2001 (0x40000).
D77-15 is used for Program EPROM’s that are 27c4001 (0x80000).
I have a D77-15 so I need to find a Taito F3 game that uses 27c4001 EPROM’s and of the games I could convert to I decided on Elevator Action Returns.
Now I needed to de-solder all the EPROM’s for graphic and sound data:
Unfortunately at this time I didn’t yet have a de-soldering gun and was resorting to using a manual pump and a cheap hot air station to help pry out the EPROM’s and of all the 336 via’s I accidentally damaged one:
Since I was going to put sockets in place I decided I would do the trace repair on the top of the circuit board with thin Kyna wire so it could easily be concealed under a socket:
Which was threaded through the via, to be soldered on the reverse of the PCB along with the Sockets legs:
With this problem resolved I then cleared the solder mask from IC4 where I needed to place a socket for a position which was not already populated and proceeded to solder in all the required sockets:
I then used my EPROM Eraser to erase all the old EPROM’s:
Using the information from the Mame Taito_F3.cpp I had figured out that to do this conversion I would need to programme the EPROM’s with the data from the contents of the MAME elvactr.zip as follows:
ELEVATOR ACTION RETURNS TAITO F3 CONVERSION:
IC04 - 27C160 (100ns) Mame ROM : e02-01.4
IC08 - 27C160 (100ns) Mame ROM : e02-02.8
IC12 - 27C160 (100ns) Mame ROM : e02-03.12
IC17 - 27C4001 (100ns) Mame ROM : e02-16.17
IC18 - 27C4001 (100ns) Mame ROM : e02-10.18
IC19 - 27C4001 (100ns) Mame ROM : e02-11.19
IC20 - 27C4001 (100ns) Mame ROM : e02-12.20
IC32 - 27C2001 (120ns) Mame ROM : e02-13.32
IC33 - 27C2001 (120ns) Mame ROM : e02-14.33
IC38 - 27C160 (100ns) Mame ROM : e02-04.38
IC39 - 27C160 (100ns) Mame ROM : e02-05.39
IC43 - 27C160 (100ns) Mame ROM : e02-06.43
IC45 - 27C160 (100ns) Mame ROM : e02-07.45
IC47 - 27C160 (100ns) Mame ROM : e02-08.47
All the now programmed EPROM’s were then inserted in their appropriate sockets and EPROM windows covered up with electrical tape:
I then tested the cart on my Taito F3 and it booted fine, however I was getting some very strange random flickering single pixels at various certain places in the game as circled in the image below:
This problem is often caused in conversions by EPROM’s whose speed is too slow. Taito F3 hardware requires that everything apart from the two AUDIO PRG EPROM’s at positions IC32 & IC33 need to be running at 100ns or faster.
Since the game was running fine and the audio had no issues I only needed to look at the six EPROM’s that held graphic data (IC4, IC8, IC12, IC43, IC45 & IC47).
I dug out a spare known good 100ns 27C160 EPROM which I used to programme, replace and test each of those IC positions until I found the culprit bad EPROM which was then thrown away and I now had a perfect working version of Elevator Action Returns!
I then removed the old labels from the cart:
And as best as I could reproduced new labels for it making sure to add a note that it is a conversion:
I went to a local print shop and got a few printed out and then added them to my F3 cart:
And now to enjoy my new game:
Holy shit dude. That’s amazing work and exhibits a very high level of dedication and knowledge right there.
Very impressive. Also, that’s definitely the game to do it for too.
What an awesome post! I love seeing how you logically approach each step. Where’d you learn all this cryptic info?
For a while I did also consider Darius Gaiden which was also possible but I’ve never really been a fan of that series and thought I’d get way more enjoyment out of Elevator Action Returns.
It has all been from learning as I go, taking everything a step at a time.
Mame’s github repository did the majority of the hard lifting for this project and the studying of various Taito F3 game PCB images that I found via google images so I could see what was different between games.
I wish I knew and understood a lot more.
Had a bit of a hit in my confidence recently after I’ve not been able to revive a Konami Asterix PCB I bought after many many hours of work trying to figure out its problems and making almost zero progress even after fixing a fair few minor things that I found to be bad on it.
I know all about getting your confidence kicked around. I had the same thing happen on a Raiden Fighters Jet PCB I got on the cheap. I’ve also had a model 1 Sega CD I’ve been struggling with for months.
It’s funny after all kinds of successful work one or two rough projects can throw you a bit.
Brilliant! Great work.
Personally, I think I would’ve made the same choice. Elevator Action Returns is just so unique and interesting, not to take anything away from Darius Gaiden.
“Crush the old order!”
Amazingly well presented repair.
Thanks for the great content.
SEGA Mega Drive PAL VA4 Refurbishment & Modding:
The Very Amateur Past:
One of the very first mods I tried to do when I was starting to get back into retro gaming in 2015 was putting a region switch on my Mega Drive, which is a rather simple mod and because of this a good mod for beginners to attempt.
I had no soldering experience and I was using cheap and nasty tools, but it worked and gave me enough confidence to later the same month remove the RF modulator to allow me to add a rear stereo audio jack to my Mega Drive so I would no longer have to have a cable reaching round the front of my Mega Drive to obtain stereo audio output.
The results obviously weren’t the greatest…
Poor solder joints, bad wire choice and barely soldered in frayed wires that could potentially short out:
I’m not even sure now how I even managed to remove the RF Modulator without damaging the via’s as I didn’t even know what de-soldering braid or pumps were then:
I ran speaker wire directly from the front stereo jack connections with no care about interference to the rear of my Mega Drive and didn’t bother to clean up any flux:
I then also did a bad job of connecting ground to the stereo jack via a capacitor leg:
Perhaps due to my mechanical engineering background I am fortunate that I choose good placements for my region switch and rear stereo jack and did very clean installs of them:
In 2019 I decided I would properly refurbish my Mega Drive.
All the previous mods were removed, flux residue was cleaned up and via’s properly de-soldered.
PAL VA4 Mega Drive Recap:
After testing each individual capacitor as I was removing/replacing them I could see that every 100µF & 220µF value capacitor bar one at position C79 was capacitance testing outside of specification tolerances and all the 47µF capacitors were all just on the borderline of the 20% tolerance.
C01: 220µF 16v 8mm
C04: 100µF 10v 5mm
C05: 10µF 16v 5mm
C13: 10µF 16v 5mm
C23: 100µF 10v 5mm
C24: 100µF 16v 5mm
C30: 10µF 16v 5mm
C31: 10µF 16v 5mm
C32: 220µF 16v 8mm
C38: 10µF 16v 5mm
C40: 1µF 50v 5mm
C41: 10µF 16v 5mm
C42: 1µF 50v 5mm
C43: 10µF 25v 5mm
C44: 1µF 50v 5mm
C49: 100µF 16v 5mm
C50: 220µF 10v 6.5mm
C51: 220µF 10v 6.5mm
C52: 100µF 16v 5mm
C53: 100µF 16v 5mm
C55: 10µF 16v 5mm
C57: 10µF 16v 5mm
C58: 1µF 50v 5mm
C59: 47µF 16v 5mm
C60: 47µF 16v 5mm
C61: 1µF 50v 5mm
C62: 1µF 50v 5mm
C63: 47µF 16v 5mm
C64: 10µF 16v 5mm
C65: 47µF 16v 5mm
C66: 47µF 16v 5mm
C67: 47µF 16v 5mm
C68: 47µF 16v 5mm
C71: 10µF 16v 5mm
C72: 10µF 16v 5mm
C74: 100µF 16v 5mm
C79: 100µF 16v 5mm
C86: 100µF 16v 8mm
Replacing some Additional “Optional” Components:
I then also replaced the two original 7805 voltage regulators with more efficient 78S05 voltage regulators and because this Mega Drive is used essentially 99.5% of the time in NTSC mode I removed the original PAL 53.203MHz clock crystal (OSCI):
and replaced it with an NTSC 53.693175MHz clock crystal so I could get exact timings for 60hz:
Re-Tension Cartridge Connector Pins:
By using a small flat headed screw drivers I very gently applied a little bit of pressure to each of the cartridge pins to increase the tension as they were a little loose from years of abuse:
Region Modding the VA4 Mega Drive:
On the Mega Drive you will find 4 sets of jumpers labeled JP1-4.
Simply JP1 & JP2 control language, JP3 & JP4 control video output and the regions are set as follows:
To get a blank state on a PAL Mega Drive you need to cut the traces between JP3 & GND and JP2 & +5V:
For a cleaner install and better routing I decided to run my wires underneath the Mega Drive and thread the wire through the via’s and soldered them on the topside of the PCB:
Using a DPDT ON OFF ON switch we want to connect it up as follows:
- Left: JP4 or JP3
- Middle: Ground
- Right: JP1 or JP2
We then want to connect both the left and right terminals with 1.2K ohm resistors that are in turn tied together at the other end and connected to 5v to create a pull-up resistor so that when the language or video jumpers are not connected to ground through the switch they are “pulled” up to 5 volts.
NOTE: Instead of using a switch you could also try a switch-less mod
Adding a Halt Switch:
If you connect pin 17 of the 68000 CPU to ground the CPU will halt and stop running. This is great to be able to freeze the Mega Drive where you would usually be unable to pause and to be able to get a clean screen in those games that obscure the screen when paused.
So by connecting a SPDT ON/ON switch as follows we can have a halt switch:
- Left: Floating
- Middle: Ground
- Right: CPU Pin 17
NOTE:This switch will not pause SEGA Master System games as they use the Z80 CPU.
Since I had previously installed a region switch which I had positioned to the left on the lower case house, I just needed to drill and file a second hole for this new second switch:
Again I routed the required wire from the 68000 CPU pin 17 underneath the PCB and piggy backed the ground from the region select switch.
Both Switches installed:
Due to the positioning and using slide switches, both switches are well hidden but easily accessible:
Installing a M1 Mini Mega:
To improve my Mega Drive’s audio output I decided I would install a M1 Mini Mega PCB:
Since I already had a stereo audio jack installed I hooked its audio output up to that.
NOTE: The caveat of using a M1 Mini Mega is that the volume slider is now sadly non-functional
Widening the Cartridge Slot:
So I could insert Japanese cartridges without the need of a pass through adapter I decided I would widen my cartridge slot by using a fine file and linishing paper to remove the bare minimum required:
With a Japanese cartridge inserted:
VDP Pin 50:
Pin 50 of the SEGA 315-5313A is the video sub-carrier (marked in pink) and due to it running very close to the RGB line can cause video interference especially along the Blue line.
VDP pin 50 and RGB traces PCB top side:
VDP pin 50 and RGB traces PCB bottom side:
You can optionally lift leg 50 of the 315-5313A to remove this interference, however you will then be unable to use composite video for the dithering.
If you wish to fully convert a PAL Mega Drive into a NTSC machine you will also need to lift Pin 7 of the CXA1145P and connect it to +5v. This will then correct the composite colour burst frequency to NTSC.
However, if you are using RGB then there is no need to do this step at all.
This is a great write-up. It makes me want to revisit my shitty Genesis mod I did around the same time. I’m pretty terrible though so I’d probably do a worse job now though.
I should at least figure out a way to test caps and replace everything before it’s too late.
Awesome post! Super cool to see your original mod work and your update! Always fun to mark your progress. I need to do a region mod to mine as well.
SEGA Mega CD Model 1 Refurbishment:
I recently purchased this PAL Mega CD and like with the Game Gear these are notorious for having bad capacitors that should be replaced, so a refurbishment was in order:
SEGA Mega CD 1690-18 Recap:
After opening up the Mega CD and gently removing both the ribbon cables I was able to remove the main motherboard PCB of the Mega CD:
Since the ML2016 T25 Rechargeable Battery (25 mAh) was dead and because I wanted to socket the BIOS chip I removed both of them along with all the capacitors in one go:
It was hard to notice until the capacitors were removed but the majority of the SMD capacitors had been leaking and causing some corrosion to the contact pads and especially bad are that the C41 and C47 had caused some corrosion to occur on some of the BIOS via’s:
SEGA Mega CD Motherboard PCB Capacitors
C41 10µF 16v SMD LEAKING!
C42 10µF 16v SMD
C43 10µF 16v SMD LEAKING!
C44 10µF 16v SMD
C45 10µF 16v SMD LEAKING!
C46 10µF16v SMD LEAKING!
C47 10µF 16v SMD LEAKING!
C48 10µF 16v SMD
C49 10µF 16v SMD LEAKING!
C50 10µF 16v SMD
C51 100µF 6.3v
C52 100µF 6.3v
After measuring the original SMD capacitors I was able to find some Nichicon UWX1C100MCL2GB SMD capacitors that are suitable drop in replacements. Sadly these parts are now EOL so stock is limited.
Since these SMD capacitors are tiny (only 3mm Diameter x 5mm Height) they are difficult to work with, so unless you are a bit OCD like me it is probably best just to go with mini electrolytic replacements.
NOTE: Care needs to be taken when removing and replacing the capacitor at position C51 because a resistor is soldered to it underneath the PCB.
I also removed all the capacitors from the Power PCB:
SEGA Mega CD Power PCB Capacitors
C1 10µF 16v
C2 10µF 16v
C3 10µF 16v
C4 10µF 16v
C5 10µF 16v
C6 10µF 16v
C7 10µF 16v
C8 10µF 16v
C9 10µF 16v
C10 10µF 16v
C11 10µF 16v
C12 10µF 16v
C13 10µF 16v
C14 10µF 16v
C40 100µF 6.3v 105c
C41 100µF 6.3v
C42 100µF 6.3v 105c
C43 100µF 16v
All the capacitors on the power board tested good with only a couple around the voltage regulator heat sink having any slight variance but well within acceptable he 20% tolerance.
There are also a few capacitors on the optical drive PCB but at this moment in time I am not going to touch them while the optical drive is functioning.
My take away from this recap is that you can probably ignore recapping the power board but you should 100% remove and replace all the original 10µF 16v SMD capacitors as soon as possible!
I now soldered in a socket for the BIOS chip and re-assembled the Mega CD for a quick test:
and everything was working as expected!
Modding the Mega CD for Multi Region BIOS loading:
With the original BIOS removed I now needed to dump its data contents:
To do this I inserted the BIOS Mask ROM into my TOP3000 universal programmer and set it to 27C1024:
As with SEGA Mega Drive Mask ROM’s the dumped data needs to be byte-swapped to be readable:
After byte-swapping my BIOS dump I got a CRC of: 529ac15a which is identical to other PAL Mega CD 1 BIOS files you can find preserved online.
At this point I could have just burnt a modified universal SEGA Mega CD BIOS. However, there are apparently some minor and very trivial issues with doing that and since my Mega Drive is region modded already I decided I would create a multi-BIOS that would change the Mega CD region based on what region my Mega Drive is set to.
For this I needed to use a 27c4096 EPROM which could hold all three region BIOS ROM’s and use its bank selecting legs 38 and 39 to toggle between them.
This would be achieved by connecting leg 38 to JP3 or JP4 (video) on the Mega Drive and connecting leg 38 to JP2 or JP1 (language) to leg 39 as follows:
|DATA BANK||LEG 38||LEG 39||REGION|
|BANK 02||+5 Volt||Ground||JAPAN|
|BANK 03||Ground||+5 Volt||PAL|
|BANK 04||+5 Volt||+5 Volt||USA|
With this figured out I obtained the original USA SEGA CD BIOS and a Japanese Mega CD BIOS from online and byte-swapped them ready to be used.
Then in BINman I loaded them into each file slot in the correct order along with my original PAL BIOS dump:
and then combined them altogether:
This gave me a 4Mbit file with the CRC of ffa52927 that was ready to be programmed to the 27C4096. Leg 38 and 39 then needed to be bent upwards before being inserted into the BIOS socket:
We now need to make a connection from the Mega CD to the Mega Drive utilizing some unused pins on the expansion connectors.
- Expansion Connector PIN 4 needs to be connected to LEG 39 of the 27c4096
- Expansion Connector PIN 6 needs to be connected to LEG 38 of the 27c4096
NOTE: After doing this make sure to bend legs 38 & 39 down the outside of the socket otherwise they could potentially short on the metal shielding when everything is put back together.
We now need to look at the interconnecting piece of the Mega CD:
This needs opening up:
The Ferrite bead around the PCB needs to also be removed which just clips together:
On the reverse of the PCB carefully lift up the ceramic capacitor that is in the way and solder wires connecting expansion ports pin 4 and 8 between both connectors in parallel:
With the wires in place you will not be able to re-assemble this interconnect and we need to modify its housing slightly by filing a 10mm wide space with a 2mm depth at around 12mm from the left hand side:
The Mega CD now can be re-assembled.
Finally on the Mega Drive side we need to solder two wires between the expansion connector over to the JP jumpers:
- Expansion Connector PIN 4 needs to be connected to either JP1 or JP2
- Expansion Connector PIN 6 needs to be connected to either JP3 or JP4
With everything put back together and hooked up:
Mega Drive region switch set to PAL:
Mega Drive region switch set to USA:
Mega Drive region switch set to JAPAN:
NOTE: Switching Mega Drive regions while the Mega CD is powered up is not advised and can lead to the Mega CD crashing. So Power off the Mega Drive before changing regions.