SEGA MEGA DRIVE (Genesis) Games - Part 2 - Interesting Resistor FIX

[@amaiorano]

Having had experience with this, please don't use a power drill on those screws. They screw into plastic, which is so easy to strip. Use a hand screwdriver, and do that left turn trick until it just drops, then screw in softly just until it stops turning, and no more. Have stripped a few NES carts by accident, so just sharing my lesson learned :)

[@rfmerrill]

Cartridges from this and earlier generations typically had Mask ROMs on them. Mask ROMs have their contents baked into them when the chip is made. PROM is blank when the chip is made and is electrically programmed once, and cannot be erased or reprogrammed after that. A simple way to make PROM (sometimes called one-time-programmable/OTP memory) is with an array of tiny fuses that you program by running a high current through it that blows the fuses. EPROM is erasable through some special process, usually exposure to UV light (these usually have a window that's covered with a sticker for that purpose) EEPROM is electronically eraseable. Modern EEPROMs are often either NAND or NOR flash, but you still see chips with the older, slower technologies.

[@GadgetUK164]

Fantastic - 5 out of 5!!!! You are correct on the chips - PROMS or Mask ROMs. EPROMs will have a window to UV erase. EEPROMs (extra E at the start there) can be electronically erased and don't have a window, but they didn't use EEPROMs on these carts.

[@Mymatevince]

Thanks for the info Chris :-)

[@MayaPosch]

Specifically they used Mask ROMs (MROMs) because of the higher capacity provided. PROMs are written once (physical connections blown to form '0' values), whereas EPROMs and EEPROMs (and related Flash memory) use floating-gate MOSFETs (FGMOS) cells which can be written many times, but at the cost of their long-term data retention ability, both in their construction (capacitive gates) and write endurance (writes physically damage the resistive material around the FGMOS cell). Nintendo Switch cartridges use XtraROM from Macronix, which is also an FGMOS-type storage, but rated for long-term data retention (20 years at 85C). Of course, if you go wild with hot air and 450C soldering/brazing irons, you'll erase the contents of those cartridges in no time, as FGMOS discharge as a factor of temperature.

[@GadgetUK164]

@@MayaPosch Mask ROMs don't provide higher capacity in these packages! They are the exact same size as the EPROM equivalents. They went with mask ROMs due to cost. It's way cheaper in volume vs the cost of EPROMs and the associated programming time.

[@joseluissertajeperez4980]

🎳🎥📷⚽🎮🏅🎉🏆🎁

[@guilhermephsor]

That resistor to the ground is called "pull down", it gives a 0 signal to that pin, unless the console sends a 1 (5v) to it.

[@laszlomarktoth7492]

Yes this is the truth, and when you are measure 0.7kOhm this is also an intern pull down resistor. And also this is the reason why the measure value is different, because you soldered a 1kOhm resistor between data out pin and ground, you measured that resistor of course. If you solder less resistant (750Ohm E24) resistor you will measure less too (almost same as the internal ones). But anyhow it was a great work!

[@Ratzfaz]

@@laszlomarktoth7492 The Multimeter is in Diode Mode, and reading a Voltage not a Resistance. The ~ 0.5 to 0.7 V is usually the voltage drop of a Diode.

[@laszlomarktoth7492]

Dear Ratzfaz, yes you are right Vince measure in diode mode, but diodes have polarity and Vince also change the probes, so he measured voltage on the resistor, on a pull down resistor resistance. This is why working this hack, if another ROM IC which designed with pull up resistor it was it work.

[@Ratzfaz]

@@laszlomarktoth7492 look at 10:53 and where has he changed polarity ?

[@laszlomarktoth7492]

@@Ratzfaz oops yes, he has not change the pins.

[@rodrigollamas8129]

It's always nice to see this kind of video, congratulations Vince.

[@nickwhite5528]

Found this video, followed what you did, added resistor, game now working - you are a star - thanks -awesome

[@abeleski]

Here in Australia, the Brazilian technique is something the girls do down under 😉

[@jamesdye4603]

Your best videos are the ones where you fix things. Your less successful videos are a learning experience, which is a win for all of us.

[@Mymatevince]

Thanks James :-)

[@Fuzy2K]

2:05 -- For a split second there, I thought your multimeter made that piano noise XD

[@Mymatevince]

Haha :-)

[@MrMacizin]

@@Mymatevince end 2020 🔧🛠️🧰⚙️

[@markvandesande8855]

Hi just to say this trick was being done in the uk in the 1990's with these chips and others a very common issue with chip i/o. Well done Vince.😁

[@Operational117]

5 out of 5?! That’s Bonkers! (pun intended) But yeah, these traces right near the pins are an Achilles’ Heel. Wear and tear. Time hasn’t been kind to them. So it’s important what people like you are doing. Same goes for the resistor-fix. EDIT: After extensive research, I’ve found out what that pin (pin 12 from lower left (top view)) does: it’s the “inverted Output Enable” (inverted OE for short), which means if the pin is low, output is enabled, otherwise it’s disabled. *If the inverted OE pin is malfunctioning, it may be permanently set high, which essentially prevents the data from ever leaving the ROM. Then again, I don’t have much knowledge about Sega ROMs... reading a Fujitsu-manual online while writing this edit (Sega used Fujitsu’s Mask ROMs for at least some of the SEGA Mega Drive games).* BONUS INFO: That pin is next to a ground pin (pin 11), next to that (pin 10) is the “inverted Chip Enable” (inverted CE for short). Inverted CE and inverted OE work in tandom to deliver data as quickly and/or as efficiently as possible (don’t know which, honestly). CE to activate chip. Address pins (A0 to A17) to set the data output to a specific memory position). OE to send data through output pins. Then disable botH CE and OE. Rinse and repeat. There’s also an “A negative 1” input pin (A-1) and an “inverted BYTE”-pin that gives it a different behaviour: If inverted BYTE is set high, all output pins (O1 to O16) will send data. (16-bit data transfer mode) If inverted BYTE is set low, only the first 8 pins will send data, the rest will send high impedance (except O16, which becomes the A-1 input pin). (8-bit data transfer mode) While inverted BYTE is low, A-1 will determine whether to send the first half (A-1 low) or the second half (A-1 high) of the data. The data is explicitly stored as 16-bit data entries, so this is required to select between the two halves (because not all data is stored as full 16-bit chunks... some are stored as two 8-bit chunks compressed into a single 16-bit entry. Text is a good example, as each letter is almost explicitly stored in 8-bit chunks. Storing each letter in 16-bit chunks would be a huge waste of space!).

[@BrianOfAteionas]

Thanks for the info! I was a bit curious why tying a pin to ground would solve the issue completely without causing other problems. However, it's still unclear to me why that pin wouldn't be getting the a low signal to enable output in the first place.

[@Mymatevince]

Thanks for posting this Operational :-)

[@SparksNZeros]

EPROM - Eraseable Programmable Read Only Memory (usually with the little window you expose to UV light), EEPROM- Electrically Eraseable Programmable Read Only Memory. The chips you find in cartridges are typically just Rom's, they are write once read many chips that can't be altered or changed, you can take data from them, pass them through another chip to make alterations (like translation adapter boards) but the ROM remains the same.

[@Mymatevince]

Thanks Sparks :-)

[@joseluissertajeperez4980]

🔧⚙️⚙️🧰🧰🛠️🛠️⚽🎳🎳🎮

[@joshm264]

Bad contacts, probably the most common fail for electronics. Great fix as always!

[@EEVOL]

You are the man Vince. You’ve come so far, we all have learned along with you throughout the years. Cheers!

[@Snufl]

Some years back there was a "tip" going around about how brasso fixed everything about your old, worn-out vintage game cartridges. Like I said on the other video, sure it worked great to clean the contacts, but very few people doing this for a quick sell had the patience or the tools to properly clean the brasso out of the games afterward, and it pooled up on that little divider and slowly ate away at the traces under it. Generally an easy fix, as demonstrated, but frustrating that it ever happened to begin with.

[@8inary]

Your work demonstrates something I often say about fixing electronics, some days are just bad, and you feel like packing up because nothing seemingly works, then you get days like these, where you just keep knocking them out repaired. I guess that is similar to golfing, you can spend thousands on your gear, but it is not a guarantee to having a perfect day. So if you are feeling down about not being able to repair something, take a break and try again later or another day, dont give up, each process/repair is a learning curve.

[@duncanward6226]

Thanks for this video - just had the same problem with the same game (Flicky) - followed your procedure, found the same pin at fault, 1k resistor sorted it.

[@JMUDoc]

All ROMs are erasable, Vinny... if you've got a hammer.

[@BADSeCt0R2XP]

Or 9volts and tons of educated insanity 😒

[@MrMacizin]

@@BADSeCt0R2XP 1988 1989 years past 🛠️🧰🛠️🧰⚙️🔧⚙️🛠️🧰⚙️🔧🔧

[@joseluissertajeperez4980]

End 2020🧨🎂🥉🥉🏆🧰🎳📷🔧

[@joseluissertajeperez4980]

📷🎳🧰🎮🔧🏆

[@rfmerrill]

One thing your fiberglass pencil is good for is to clean contacts. You don't need as much pressure for that and so you end up with way fewer fibers coming off.

[@mikebinn3128]

19:10 haven't seen that game in a long time jeez. How fast time flies.... Flicky

[@Satoriga]

I got an @tgames legends flashback that came with 2 6-button controllers and an sd card slot for roms. Came with flicky, mega man 1 and 2, streetfighter, and galaga.

[@joseluissertajeperez4980]

🎮🏅🎉🏆⚽

[@SlartiMarvinbartfast]

Vince, I know you quite correctly don't like to use fiberglass pens (the fibers are terrible and get everywhere) - a far better alternative is something called a Garryflex Block (I use 120 grit) - depending on what you are doing you can use it whole or cut a piece off if you need a smaller bit for those hard to get at places. There's no fibers from that, just a bit of 'grit' which is easy enough to clean up. Give it a try, it's perfect for all kinds of PCB uses including cleaning up edge connectors as you are doing in this video (don't get too carried away and rub too much though or you'll take off too much material). You can find them on Amazon for about £6 each and they last for ages - I've had mine for about five years and despite regular use the block has only shrunk by about half.

[@laszlomarktoth7492]

Fiberglass almost same dangerous like asbestos!

[@Mymatevince]

Thanks M Jons, I just ordered up a 120 grit one on eBay, £5.85 so worth a go. I would much rather bits of grit on my fingers than those fibers!!!! Nice one :-)

[@SlartiMarvinbartfast]

@@Mymatevince Nice, hope you find it useful (it's basically a large pencil eraser which is abrasive, you'll see :) ).

[@50t5]

You have become quite a handyman. Good job. Only thing that has always bothered me in your videos is the music but now i found a solution: Wintergatan has a free licence available for youtubers like you. Just google their website and music.

[@jaredl2239]

Yay MMV Massive! Yay patreon supporters! You guys are appreciated for making these videos possible.

[@chantafreak]

I would have filed down the edge of the plastic just a bit where the contacts fail and maybe put some sort of a dampening material to avoid future friction

[@Shinratotil]

u SIR are a legend, just saw your video and I was having the same problem on my sonic, and follow your steps and it worked. You are the man. Thanks

[@smitcher]

It is the plastic bit that's causing it but it's not the rubbing that's doing it... putting in the cartridge is flexing the edge connector slightly back and forward, stretching one side and compressing the other. Over time the thin tracks break due to fatigue. It's bad design really but no company wants things to last these days or back then...

[@jawmedia7575]

Batting 1000 Vince. Great job 4 for 4 excellent

[@danieltillman3858]

You can dremal or sand down where the plastic meets the solder bridges. Great work!

[@virtuousZeus88]

Yeah switch killer to mega driver master lol... I watched all your switch videos and got to say they are some great videos to watch... all your videos are great to watch.

[@Mymatevince]

Thanks Caesar :-)

[@jeffpozniak9159]

Thank you for this video. Your technique helped me diagnose and repair one of my previously dead Genesis cartridges. Cheers!!

[@telemedic2000]

Ok I have watched a few of your vids, and this series was so good, you now have another subscriber. Keep it up!

[@paulmckinder3082]

I remember playing italia 90 for many many hours well done sir

[@DouglaskaT]

Vince, what video camera and or microscope setup do you use, also, what type/kind of solder do you use as well. Thanks for all your hard work!!! It's amazing!!!!!

[@r.a.w.talentart]

Nice lil series Vince. Anything to do with fixing megadrive stuff grabs me!

[@Mymatevince]

Thanks RAW :-)

[@SeanJunYanLiew]

Really love the idea of fixing a whole lot of different items. But we love seeing your brick items also LOL. No worries you're a master in my eye, not a killer! They are dead before you had them anyway. Cheers mate!

[@semresistencia]

Thank you very much. Putting in the resistor saved my Sonic 1.

[@moosesugar]

vince i will make you aware youtube is holding back notifications again i had to ring the bell again today and then all your videos came through some from over a week ago all the best jon

[@Mymatevince]

Thanks Jon for letting me know. Cheers for re pressing the bell again :-)

[@minkster1983]

Brilliant two part video Vince and absolute triumph for you 5/5 fixed

[@dannyhtheretrogamingmaster9548]

This is the perfect time to fix these old megadrive games as they are getting collectible. These ones are particularly so. Hopefully you'll be able to get some old nes and snes games up and running soon.

[@BADSeCt0R2XP]

Agreed. Especially that micromachines (that I honestly believed that would be unfixable) and the megagames6 ones (there was three versions of them I believe, i think that the one displayed here is vol.1)

[@MrMacizin]

@@BADSeCt0R2XP end 2020 🛠️🧰⚙️🔧'¿?

[@ngogercin]

That resistor trick was neat, as a newb I feel enlightened!

[@brutlern]

Two videos in one day. Must be 2 for 1 Black Friday special.

[@Mymatevince]

Haha :-)

[@alessandrolima4396]

Amazing video. Here in Brazil this tip of the 1K resistor is well known.

[@Mymatevince]

Thank you. It is a great tip :-)

[@joseluissertajeperez4980]

🎖️🏅🥇🥈🥉⚽🏆🎉🎊

[@colinfielder6695]

Hi Vince, I don't know what's more enjoyable, watching you fix things or your excitement when you do! Also do you think the age old wiggling it if it doesn't work might be the cause?

[@joseluissertajeperez4980]

🎮🥇🥉🏆🎖️🏅

[@Mikie1959]

you are becoming quite the electronics tech .

[@Mikie1959]

I truly mean that you have progressed so much since I have started watching your videos and I love it when you get so excited when you fixed the very first cartridge.

[@Owazrim]

Nice recovery on the carts. That resistor fix is a good thing to know.

[@MrMacizin]

END (2020) 😂😂😂😂😂

[@devinkrike5968]

Curious why the resistor trick works. You are essentially pulling down on of the address or data pins. Something should give out when the console requests something that uses that address bit or data bit. Unless I misunderstood the purpose of the resistor.

[@BrianOfAteionas]

I thought the same thing, but then I read Operational117's comment and one of the things written was: "After extensive research, I’ve found out what that pin (pin 12 from lower left (top view)) does: it’s the “inverted Output Enable” (inverted OE for short), which means if the pin is low, output is enabled, otherwise it’s disabled. " Also he talks about the Chip Enable pin and some other stuff. Worth a read.

[@StromboliKicks]

@@BrianOfAteionas can you tell me what you understand by "pin is low"? I still don't get why the resistor works. I thought the pin had a broken connection to the IC chip(die).

[@BrianOfAteionas]

@@StromboliKicks To be honest I also want to understand why the chip was not getting the correct signal to begin with, and why the resistor works. All I know is that 0 Volts (logic low) is to be applied to that pin in order to enable output, and somehow the resistor accomplishes that.

[@colinsmith6480]

nice fixes the resistor fix is one i will take a look at for some of my problematic carts !

[@eightohmmedia]

Hey Vince, yet again another great fix, I agree with Guilherme H, the resistor acts as a pull down, 1k is a usual value. Well done you..!!

[@MrMacizin]

end 2020 🛠️🧰🛠️🧰⚙️🔧⚙️🔧

[@JuicyJakeRepairs]

im glad these were saved from the skip!

[@guidomersmann9744]

Please don’t use an electric screwdriver without torque control on plastic tabs. That is as bad as people using these big drill like drivers to build ikea furniture. This will wear the plastic tabs massively on the inside and the put the plastic under stress. I know it saves time, but it hurts so much :) Get a small screw driver size one. Beside that: Great Job!

[@DEmma1972]

100% fix. great job and 5 games saved from the tip

[@Mymatevince]

Thanks Emma, I was very lucky with this lot. I love that little resistor trick :-)

[@SKYishow]

Nice job! What's your favourite Sega mega drive games of all times?! Mine is : Comix zone, and Earthworm Jim .

[@andrewmcneill1165]

Well done mate....cloud nine feeling.

[@The-Warm-voice1359]

oh man i l😘ve sega md i l😘ve classic games i was playing moon walker in that time in 1993 the best game on sega 4me they street of rage 1 2 shadow of dancer ninja with white wolf shinobi sonic part 1 donald duck quick shot road rash i forgot rest😩 well wonderful video dude thx

[@UltimatelyEverything]

The was satisfying to watch great work with this one Vince this was a perfect fix as far as getting them all working.

[@TomMannCenturia]

Need a relaxing watch now. Just watched the MMV game gear screen mod video, that was bodering on harrowing!

[@Mymatevince]

Haha, that was torture. This is easier to watch :-)

[@MrMacizin]

@@Mymatevince ¿ (2021) ? 🛠️🧰⚙️🔧

[@GranieNaSpontanie1994]

Superb fixing 👍 Thanks for video!

[@joseluissertajeperez4980]

🎮🏆🎉🏅

[@CatsAreRubbish]

An idea for curing your solder mask... could you use a UV bank note checker to do them all at once? They have a 5 inch(ish) long UV bulb, as cheap as £10 on Amazon.

[@moderusprime]

Sega carts sure do fail a lot due to manufacturing flaws.

[@TATTIEPICKER]

Shinobi. What an arcade game. I spent many Saturday afternoons in the arcade playing that along with splatter house. 😁

[@BADSeCt0R2XP]

The one at display here is actually Shinobi II and was a megadrive exclusive I believe. (It may have appeared on the arcades through sega’s megatech/megaplay platform which was pretty much a megadrive in an arcade cabinet)

[@joseluissertajeperez4980]

🎮⚽🎖️🏆

[@Jasugunnm]

My Mate Megadrive Vince

[@OrientalAttack]

In Brazil we call this fix "Gambiarra"..

[@DarkoPetreski]

What does it mean if you don't mind me asking?

[@retropcscotland4645]

@@DarkoPetreski Gambiarra · A brazilian expression. It basically means to use improvised methods / solutions to solve a problem, with any avaiable material.

[@SeanFix]

Vince, do you know why the 1k ohm resistor trick works? thats pretty awesome! great job man!

[@DarkRequiemFilms]

Brazil does it again!

[@joseluissertajeperez4980]

[_____] ? 🎮🔧⚙️

[@TheSkaldenmettrunk]

Yes! Part 2 is here and 5 out of 5. Perfect!

[@paullefur6213]

Next to be a Nintendo Ninja lol, great vlog Vince

[@joseluissertajeperez4980]

🎮🎉🏆⚽🎖️🎁

[@TobiEstosWorld]

man this 1K fix is near to magic for me. great !

[@colintx800]

"MR MEGA DRIVE" 😂😂😂😂😂

[@SparksNZeros]

I've found most dead carts are down to improper care and storage, the issue of the traces being literally worn away by typical usage is very rare, more often we've found that corrosive fluid or high humidity has gotten into the cart from the contacts, corroded away the traces where it starts to go narrow and then the carts have been cleaned with a solvent or even polish so you're left with a cart that looks like it should work but has those hairline breaks. I've fortunately yet to find any with this kind of fault however it is sad to think it can be fixed with something so simple but likely ended up in the bin.

[@TheCod3r]

Hey Vince I dropped you a link on Patreon to a handy file with pretty much every switch diagnostic check you'll need :)

[@joseluissertajeperez4980]

🥇🥈🥉🏅🎖️🏆

[@gkimble90]

Happy Thanksgiving

[@RELLIK72]

Shout out to Rodrigo Llamas, what an absolute legend.

[@cschis]

They are usually referred to as masked rooms or masked programmed rooms. The software is programed into the room during its manufacturing process

[@joseluissertajeperez4980]

🔧⚙️🧰🛠️ !?

[@illprincipe22]

Every try rubbing good old CLR on the contacts? Has really helped for me on a number of games that gave me black screens previously. Can wipe with rubbing alcohol after the CLR t9 polish and dry it out

[@gjwilson]

I always did this cheat on Revenge of Shinobi to give myself infinite shurikens Go to the Options Screen, move the pointer up to Shurikins and set them to 00, wait about 30 seconds (without moving the pointer). You will hear a sound and the ''00'' should change to an infinite symbol. Start the game and you will have unlimited Shurikins.

[@Mymatevince]

Nice cheat, thanks for sharing :-)

[@UltimatelyEverything]

Ah! Interesting cheat

[@MrMacizin]

@@UltimatelyEverything End 2020 🛠️🧰⚙️🔧

[@scottysaphir]

Perfect repair on flicky something new i have learnt

[@MrMacizin]

¿ 2021 ? 🔧🛠️🧰⚙️

[@mattwecrazy3236]

Whenever you get cocky in life..BAM! Lol

[@FlyTech2709]

Your videos are so amazing

[@topcat3824]

Come on who said coconuts while watching this video or is it just me lol Nice work vince

[@joseluissertajeperez4980]

🎇🎂🎆📷🎥🎄🥉🥇🎖️🏆🏅⚽🎈🧨🎊🎁📸🎳

[@Tim_3100]

Really enjoyed part 1 been looking forward for this

[@mikehensley78]

YES! A fix-up video.

[@The_Dee_Jay]

Excellent and interesting vid as always, really enjoyed this and part 1 - thank you Vince ☺️

[@MrStereoify]

Good as always. I am a bit surprised no one thought it's a good idea to extend the gold plated pins another millimeter or two inwards. Then again no Sega consoles are known for their reliability 🤷

[@goldend-pad5257]

first i've heard that sega isnt known for reliabilty as i've never really seen reports of mass fualts with thier hardware except for obviously the Game Gear i still have my launch sega megadrive, saturn and dreamcast all still working like a charm and they have all seen extensive long term use upto this day. Granted sega game gear was terrible due to dodgy capcitors but that wasnt anything to do with Sega directly.

[@MrStereoify]

@@goldend-pad5257 yeah I was mostly referring to the Game Gear.

[@joseluissertajeperez4980]

[___]🧰🛠️⚙️🔧

[@fluffyblue4006]

For bridging gaps, I would first tin the surfaces with flux and normal temperature. After that, I go back with either low temperature and solder only. But if it doesn't bridge right away, I'll go to the next one. And afterwards, back on normal temperature, use copper wire on those that didn't bridge. Hmm.. that solder mask.. I don't have that yet.

[@jackdanny5398]

Winner winner chicken dinner, i also wonder how many cartidges went to landfill that could have been rescued!!!

[@UnitedSpotlight]

italia 90 man i remember that game, great fixes to

[@theannoyedmrfloyd3998]

I would prefer to shave back any part of the plastic casing coming close to any circuit traces.

[@abzhuofficial]

Especially when the PCB has two holes and the plastic tubes hold the PCB via said design/setup

[@MrMacizin]

@@abzhuofficial but is new Xbox Series X 🎳🎮🏆

[@joseluissertajeperez4980]

End 2020 📷🎆🎁🎄🎆🎁🎆🎁🏅🥈🎁⚙️🧰🔧🎂🥈⚙️🧰

[@andrasszabo7386]

Flicky is one of my favourite MD games

[@RetroRick1990]

Thank you man, I was looking for some video like that for very long 😃

[@Lahire-s7l]

Cool taf 😊

[@gameclassics]

Brilliant, mate!

[@joseluissertajeperez4980]

Boom 🎆🎇🎊🎉🏆🏅📸🎈🎳

[@juanpi2693]

Hi Mate Vince I love All youre Videos

[@joseluissertajeperez4980]

🏅🥇🏆🎈🥇🥉🥉🎄🎇🎇🎉🎉🎂🎥📷📷📸📸🎖️🎖️🎁🎁🎁🎊🧨🧨🎮🎳⚽🎉🥈

[@deadlyhighdetroit6129]

Please keep up the great work brother!! Another great video!

[@richretrotech9426]

Awesome fix

[@timvangenechten5258]

Ah.... Mask ROMs, PROMs, EPROMs and EEPROMs... That chip would probably be a mask rom. mask ROMs are made with the program already on it, and used when you need a large quantity of the same rom chip. Most game cartridges would use them. A PROM is writable(Programable), but only once. You will find those when a smaller quatity of the same rom is needed. A quick search on the markings on the chip will probably give you a datasheet of those. An EPROM is indeed an Erasable PROM. They are the ones with the little window. When you find them in devices then they should be covered up with a sticker. High exposure to UV light through the window will corupt or even erase the data. EEPROMS are the somewhat more younger brother of the EPROM. These can also be erased but instead of UV light they are erased by using specific current. As said before... in game cartridges you will probably find mask roms. If you find eeproms then it will probably be either a development cartridge or a pirate copy.

[@Mymatevince]

Thank you :-)

[@MrMarshmelloBoi]

You are a fixing master!

[@SirZanZa]

the Resister method you are using is called a ''Pull Down'' pretty good hack id use a 750 Ohm next time though so it emulates the internal diode better. though in reality makes little difference

[@joseluissertajeperez4980]

*🔧⚙️🧰🛠️* ?

[@JasonSmith-tv2zw]

My Mate Mega Master, such fun!!!

[@Mymatevince]

Haha :-)

[@joseluissertajeperez4980]

🎮⚽

[@christ05roberts]

You should do a livestream video sometimes so you can have help from your KZbin subscribers when your trying to fix something it would help you out a lot so that way if you get stuck or something you can read people's comments live

[@StephenArsenault]

Vince, when you’re ready to take it to a whole other level... maybe get a EEPROM programmer and write your own replacement ROMs? 🤓

[@SparksNZeros]

sadly most cartridges used custom roms, although it's possible to write most games for megadrive to an eeprom you'd need an adapter board or to cut and rewire all of the connections that are different. their are some cartridges you CAN just drop EEPROMS in, which makes translating them to other languages super convenient (like Lagrange Point for the Famicom)

[@martinsamuelsson2322]

@@SparksNZeros megadrive/genesis used standard pinout, same as 27c322 and 27c160 for smaller games, super easy to mod