Sega Mega-Tech Repair Log

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    • Awesome log!

      Which reminds me, I used to have a Mega-Tech board with ten or so carts. I sold the whole lot to user @mar.vetto like six years ago on the promise that he would dump two carts that were included, Fantasy Zone II and Target Earth. The latter had a crude black on white label. No idea if it was a hack or preproduction copy or something else entirely.

      I think both games are still undumped.

      Yeah man, I'm calling you out.

      EDIT: I double checked and I believe the Fantasy Zone II in Mame is the System E game.

      The post was edited 2 times, last by nem ().

    • yavuzg wrote:

      ShootTheCore wrote:

      ... Hope you're enjoying the board!
      You know, I still do not know what to do with this board.
      One option is to consolize it, make a plexiglass case, put a small LCD on top of it for the game menu etc... Would be a good project but personally I'm not so into consolizing arcade systems. Also to just play games, my other Genesis + Mega Everdrive is more convenient than a 2-3 Kg bulky giant consolized mega-tech.

      Other option is to plug it in one of my cabinets. This option sounds more logical to me for now. But the downside is what will I do for the second monitor? May be a monitor switch could be used?

      Another option is to build a mega-tech repro cabinet from scratch (second monitor etc) and put this pcb in it. But that is the hardest path which I do not see enough motivitaion in me...

      For now, I just packed it and shelved it :)

      on my sega mega tech custom cabinet, I modified a cherry gold prize machine to megatech cabinet, I used as second monitor a txfbm019tb2 (7" Panasonic LCD)
      Long time ago i found a Japanese forum where was described how to wire this lcd screen to 15khz signal directly
      It works just perfect, i love it, I will add a picture of it

      The post was edited 1 time, last by mar.vetto ().

    • I love mega tech and I play it a lot
      I have been able to hack megatech cartridges with many megadrives game, just changing some pinouts and program eproms with games i want
      I till have some mega drive to megatech adpater that make me able to play most of mega drive games on megatech
      But I am not able to play my favorite game on megatech, game is NBA JAM, i tested all version from japan to Usa to Export but seems there
      is something on Megatech motherboard that stop NBA Jam to work, game start and till presentation screen and then it stops at Iguana entertainment screen
      I thing this is soemthing about the chip you repair, it is about region
      I would really love to solve this problem and play NBA Jam on Megatech

      About the two games received from NEM, I am totally open to share them with anyone, or to dump them and share files
    • For now, I've Just plugged the PCB in one of the empty JAMMA slots in my Neo Geo cabinet. wired the game select button to the button. This way, you can shuffle through the game list without even seeing it, and the selected game just got displayed on the main monitor. No need for the second monitor.

      BUT it is a Sega Mega Drive/Genesis after all. I personally don't see a major point to use this PCB in a cabinet other than its original cabinet.

      I still don't know what to do with it... :)
    • Because someone else asked, embedded are pics of everything I traded to @mar.vetto. An untested motherboard (I know, but this time really untested), wiring and nine carts. Fantasy Zone and Target Earth weren't part of the deal originally, but I told him he could have them for free as long as he would dump them. He said he would.

      Admittedly, I remembered Fantasy Zone wrong. It was the original one, not II. That one has been dumped after 2011. Still need Target Earth!

      EDIT: by the way, this is a good example of how different the arcade market is these days. I had everything up for sale (apart from FZ and TE) for 75 euros. It sat unsold on Arcade Otaku for some time before I noticed Marco's WTB thread and alerted him of my stuff. I wonder what you could fleece someone for the stuff today.
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      The post was edited 4 times, last by nem ().

    • Round 2 :)

      Its been a while since I repaired the mega-tech and shelved the genesis console which is now missing a custom chip.

      Yesterday when I was browsing the popular second hand web site, I found this ugly mega drive clone. I doesn't even have a sega logo on it. It just says "16-bit video game" on the back...

      The seller thought its a good a idea to put a photo of the PCB in his ad. It turned out to be good idea indeed because I bought this ugly looking clone when I noticed that there are real CPUs, RAMs and custom chips (which are very much look like original lsega chips) on it...

      It has a very low quality plastic case, non-existing metal case, light and crackling when you hold in your hand. Nevertheless, the PCB contains valuable spare parts, not only sega customs but a good Motorola 68000, Z80, RAM chips are good stuff for arcade repairs. For less than 10 bucks (btw it is a huge price for a clone console in my book :) ) these parts were a bargain...
    • Anyway, I thought, the custom IC on the very far right looks very much like the SEGA 315-5309 part I used to repair my mega-tech.

      It doesn't say SEGA 315-5309 but merely a meaningless number (which is common in these bootleg PCBs because of potential legal issues I guess). For internet reference it says TA-05 9446 1436260064

      The number of legs (80) matches with the original. The location closely matches where the original is located, which is close to the gamepad ports since this custom IC is responsible with IO among other things.

      Anyway, I've traced a few (not all) legs and all seem to be matching where the original IC is connected. This bootleg IC seems to be pin compatible with the original. After these preliminary checks I decided to see if it is the real deal...

      I took my non-tmss Genesis model 1 and PCB from the shelf...

      ...and soldered the clone IC which I desoldered from the clone megadrive...

    • ... and tested

      It worked!!! :)

      First there was a brief black screen when I powered on the console. There wasn't any "... licenced under sega blah blah". Obviously since this is a non-TMSS genesis version...

      With the joy of success :) I rewarded the genesis with a good cleaning with plastix

      Why I took the time to write these "not so arcade related" repair details? Well, if you come across with such shitty clone console, you can still use these parts to repair a mega-tech or an original genesis console...

    • Hello Yavuzg! Firstly, i wanted to thank you for documenting your Sega Mega Tech repair and troubleshooting so well! It's hard to find good information on that PCB. I meant to ask you for advice/expertise : i am currently working on repairing a Mega Tech myself, and the problem is as follows : Nothing appears on the large bottom screen upon boot. Also, the game title on the top screen is affected by a "stutter" (for example, it reads "GREAT GOGREAT GO" instead of "GREAT GOLF"). When pressing the TEST button (or SERVICE button, I'll have to check), the bottom screen turns on and functions normally... Any clue as to which component might be the culprit ? My intention was to follow your steps and work by elimination, but as my knowledge in components is limited, I thought best to ask you and the community first, in case I missed something obvious... Thanks in advance!
    • hello superem...

      First I must state that I'm not an expert in fixing Mega-Tech boards but from what you've said I can only speculate that your problem might be in the menu (the sega master system section for the menu) section. Since the menu glitch you mention seems minor (I mean the menu is still there but just the game names have problem) I would first check the BIOS EPROM. Check I mean dump it and check with romident. If it checks out OK I would clean the legs of it and/or replace the eprom socket.

      Then my next check would replace the RAM chip, the pseudo-ram I mentioned earlier, right next to the dip switches.

      If that doesn't work check the Z80, the legs the IC socket etc. replace it if you have a spare...

      good luck
    • Hello yavuzg,
      and thank you so much for taking the time to reply. It took me some time to realize you had posted back, sorry about that!
      I am very grateful for your directions, and I will start following them very soon. Of course, I will keep you informed of my progress (fingers crossed). I don't have what's needed to make an eeprom dump, but it's an investment I've been planning to do for a while now. BTW, if you have any advice as to what I should buy/avoid, I'm all ears...
      Thanks again !