Awesome write up! Super informative.
Awesome job, thanks for sharing
Gameboy Color No Power Repair:
Recently my brother found this Gameboy Color discarded in a field:
It is missing its battery cover and wasn’t powering on so he brought it over for me to look at and I could see that one of the battery contacts was badly corroded:
So using a Fibreglass abrasive cleaning pencil I cleaned the contact as best as I could and inserted some new batteries:
A surprisingly easy fix:
Gigabyte GA-8S655FX Socket 478 Motherboard Refurbishment:
I have been looking out for some old Socket 478 Motherboards to build a Windows '98 PC around and stumbled across a cheap local PC that contained this motherboard along with some other odds and ends that were interesting to me.
This Gigabyte motherboard boots and operates fine, however after looking closely at it, I could see that three capacitors were badly bulging and it is well known that a capacitor plague was haunting a lot of motherboards from this era (1999-2003):
These were promptly removed:
Very bad ESR as expected, but on closer inspection you can also see that not only had they bulged and were leaking fluid from the top they had also ruptured at the bottom of the capacitor:
All the bad capacitors were Chemicon KZG (3300µF 6.3v 105°C) which is a known BAD CAP.
I checked the motherboard for any other KZG type capacitors to remove but did not find any.
For my peace of mind I then in circuit tested the ESR of the other capacitors and found they were all in good standing and the ESR was mostly reading at a very good 0.2Ω reading.
I however did not have three new 3300µF 6.3v 105°C capacitors at hand, but I do keep a tub of capacitors I have removed from junk boards (or from complete recaps) that test good for ESR and capacity:
It is especially good to save the large high voltage capacitor from junk devices as they are expensive to replace and rarely go bad.
In here I found three suitable replacement Rubycon MBZ capacitors.
These I re-tested before soldering them into this motherboard:
Lastly the original CR2032 battery was dead as expected so that got replaced with a new one.
This motherboard is now good and safe to go again:
Neo Geo MVS 2 Slot (MV-2F) Refurbishment:
Back in February 2018 I bought a untested and possibly faulty Neo Geo MVS MV-2F that the previous user had tried to consolise but never got around to finishing the job.
Unfortunately the original ebay listing is no longer viewable and for some reason I don’t appear to have taken any other photographs of the unit untouched at arrival.
First Job I had to do was remove all the wires soldered directly to the Neo Geo:
The bad news was that the JAMMA edge contact pad “P” which is Video Sync had ripped off the PCB but thankfully the trace was still intact.
So using some high temperature epoxy (DO NOT use super glue as it can be conductive and when you apply heat it will give off toxic fumes, use something like Circuit Works CW2500) I bonded the JAMMA pad back down onto the PCB:
Using De-Soldering Braid I then removed as much solder as possible from all the JAMMA pads:
The original battery was leaking so it was removed:
I decided to replace it with a 3.6V NiMH 80mAh Rechargeable Battery:
Since this had an extra mounting leg on the positive side I had to cut one off to solder it flush to the PCB:
The original capacitors for the most part didn’t look too bad but I decided to fully recap it:
The MV-2F comes already fitted with a socket for the BIOS:
So I removed this and replaced it with a Uni-Bios I had programmed to a 27C1024 EPROM:
Using the Uni-Bios allows you to be able to use (then cheap) PCMCIA SRAM Memory Cards instead of having to try to find a expensive official Neo Geo Memory card.
The benefit being the PCMCIA SRAM Memory Cards tend to have an easy access user replaceable battery and a capacitor that prevents data loss when you change it and much larger capacity:
However, you must only access it via the Uni-Bios Memory Card Manager (hold A,B,C&D at boot up):
Another perk of the Uni-Bios is the ability to also be able to store High Scores:
The metal housing for this Neo Geo had become quite rusty:
So I applied some Hammerite Rust Removal Gel:
and after several re-applications and scrubbing we have a rust free housing
This I then applied a white undercoat to the top of the housing:
Left to dry and repeated to the rear:
This was then sprayed black and a gold SNK vinyl was applied giving me the finished product:
Neo Geo MVS 2 Slot (MV-2F) Graphic Corruption Repair:
Recently while I was testing my new JAMMA setup I found that I was unable to get this 2 Slot MVS to sync with my arcade monitor:
I discovered that the delicate trace for the Video Sync had broke at some point in storage:
So I had to run a small bodge wire to fix the issue:
But then… Suddenly I started getting graphical issues urgh:
I replaced the Uni-Bios with a freshly created Neo Diagnostics BIOS to help diagnose the system:
It appears I am getting the error message: VRAM ADDRESS (A8-A10/A8-A14)
So it looks like the VIDEO RAM as gone bad and from the low address that failed it looks like it was the slow ram which is a pair of SONY CXK58256MM-12 RAM:
While I did locate some identical NOS RAM in China which I ordered, I didn’t want to wait and thus looked to see if I could find a local UK seller with stock of a 5volt 256kbit SRAM JEDEC pin compatible, 32K x 8bit, 120ns or faster RAM in a 28 pin SOIC package that I could use and found some NEC UPD43256BGU-70LL RAM that I could use and got it delivered the next day:
I use a hot air station and plenty of flux to remove the original video ram:
Then drag soldered in the replacements:
Success all Diagnostic tests now pass:
Everything is now back to working as intended:
Damn that looks good! Very nice looking unit.
SEGA System 16b Suicide Repair:
I had the opportunity to buy a not working SEGA System 16b Motherboard with E-Swat ROM board from the Czech Republic for £90GBP and it looked in great condition from the photographs the seller provided:
Solder side also appear to be free of any re-work:
So I decided to take the gamble and it arrived this morning.
Upon testing it is of course dead as advertised:
There is a stable sync, a mostly black video output and no sound.
When I bought this I suspected the Hitachi FD1094 68000 CPU which contains a battery to hold program encryption keys may have died.
So I removed the FD1094:
Replaced it with a regular 16mhz x68000:
I swapped the ROM board over to the previously repaired E-Swat ROM board I and tested the board again:
It appears the suicide battery is not actually dead and runs fine. The problem appears to be on the ROM board itself. To be investigated further…
Well great, that 29" arcade monitor sparked at the back and just died…
So much for the win
Booooo! Sorry to hear it!
Replacing Japanese SEGA Mega Drive Backup Save Batteries:
I’ve had a few Japanese SEGA Mega Drive games that contain CR2032 batteries for Backup Save Data for quite a while now and decided it is time to check/replace the batteries if necessary:
Unfortunately Japanese Mega Drive Carts have the main label going from the from of the cart over to the half of the carts shell:
and worse the screws to open the cartridges are covered by a label:
After a bit of experimentation I have found a relatively safe way to remove the label to get into the Japanese cartridges with little damage caused.
First set a hot air station to it’s lowest temperature, which for me was 100°C and medium airflow:
We then want to direct the hot air at the rear label at a distance of about 2" above it doing a circular motion, trying not to concentrate in any one spot for too long and NEVER over the top of the plastic casing:
After a few minutes you may notice where the screw holes are under the label pop up a little:
If not just keep going with the circular motion and from time to time check by using your fingertips to feel if the entire label feels warm and once it is we are ready to start attempting to remove the label.
Get some flat tipped but rounded tweezers to try to gently push under the top right hand corner at the same time as pointing you hot air station at that point and after a little while you should manage to get under it:
Gently keep pushing the tweezers under until you have enough that you can grip with your fingers:
Now you need to be patient and whilst still heating the label with your hot air station just under where you are pulling up slowly work around the label starting across the top and the finally pulling it down and across.
You can either completely remove the label as such:
Leaving the back of the cartridge clean:
OR just pull up the label enough to access the screws:
Some Japanese Mega Drive cartridges use regular Phillips Screws but other also use Gamebit Screws.
To remove the PCB without damaging the main label you only want to open the cart just enough while it is face down to lift up and out the PCB:
Leaving you with this result:
I only change batteries IF they are leaking or the voltage is lower than 3.1v which in the case of this Phantasy Star cartridge was reading 3.04v, so it was removed.
IMPORTANT: I have noticed a fair few replacement batteries are not lasting no where near as long as the originals so please ensure you use only high quality branded batteries!
I also check the 16v 47µF capacitor inside the cartridges for capacitance and ESR values.
If the ESR value is higher than 0.8Ω or its capacitance is outside of a 15% tolerance in either direction then it needs replacing.
For this Phantasy Star cartridge both read bad:
Both original battery and capacitor removed:
Whilst the cartridge is open it is wise to check the contact pins:
They will likely be a little dirty as above, so just gently use a white rubber eraser to clean them up on both sides of the pcb and finish up with some Isopropyl alcohol if necessary:
You then need to re-assemble the cartridge and then stick back down the label:
If there is not enough stickiness left it may start to lift after a little while so I’d advise getting some non-solvent based paper glue stick such as Pritt Stick to add back some extra adhesion prior to re-application of the rear label.
Now if everything went well at worst you may only be able to observe a very slight bit of label crease damage to the top right hand corner of the rear label:
PLEASE NOTE: If you want to keep your saves you will have to wire up a second battery in parallel before you remove the original battery to keep power going to the SRAM IC or any saves will be lost.
In my case the only saves I wanted to keep were on the Ys III cartridge but its battery was measuring at 3.22v so did not need replacing yet.
Really clean job considering the difficulty of those labels. Nice work.
Awesome write up! Love the detailed shots!
Game Genie for SEGA Game Gear Repair:
I bought a non functioning Game Genie for Game Gear because it was very cheap, though unfortunately it is missing its mini code book and the flap that held it inside the Game Genie.:
To open it up to see what is going on we need to remove two screws at the top on the front of Game Genie:
Then remove the 6 identical sized screws from the rear of the Game Genie around the edges:
Then finally remove two shorter screws from the cartridge:
You can then lift the front off the Game Genie (but be careful not to lose the button):
Flip it over and then remove the rear of the case (again be careful not to lose the button):
You can now lift up and out the cartridge PCB as it is connected just by a socket:
Flipping it back over we now need to remove the clear plastic piece that is connected to the cartridge connector with two more screws:
Once that is lifted off everything is now free:
And you can lift off the main PCB:
Which is actually two separate pieces of plastic:
I removed the single 47uf 10v Capacitor:
Testing it in my ESR meter showed me that its ESR was very bad:
So I replaced it with a new one:
Then I cleaned the cartridge contacts and the the contact pads for both buttons.
After re-assembling it, I tested it again and it came back to life:
Only 10 more logs to post until I hit 50…
Awesome! Glad it was such a simple fix.
Yet another Game Gear Repair:
I got my hands on another Game Gear from my local tip and saved it from landfill.
This time on testing it powers up but audio was almost non-existent and the screen displayed garbage:
I had never seen a screen like this before so maybe the original screen might work?
Unfortunately the case of this Game Gear is not in the best shape and is broken around the D-Pad:
So as usual went about a full recap:
I usually replace all the Audio PCB capacitors with identical SMD mount capacitors but this time I was one short, so instead had to solder in a single regular through hole capacitor:
The Power PCB was recapped as well:
And the moment of truth:
For a change I actually have a working original screen!
@Gravitone was kind enough to send me an original good condition case from the first production run of Japanese Game Gear’s that had a flat plastic lens (Thank you so much!):
So I was able to do a case swap:
Leaving me with a very lovely condition all original Game Gear:
This thread is just wonderful, thank you for sharing.
Man that brings back memories. I haven’t played a GG since the 90s. It’s the one console from my childhood I haven’t kept around.
Great work/write-up as usual!