SEGA Genesis 2 model PC BD MD2 VA0 USA 50/60HZ switch sound problem

Good day,

I decided to mod my SEGA Genesis 2 model PC BD MD2 VA0 USA my adding a region and a 50/60HZ switch. I used this guide and both switches seem to work.

http://djoen.dommel.be/djoen.html

How ever, I noticed some weird behavior, which I had not encountered before with all the other EURO PAL Mega Drive II which I have modded so far.

Any game (JPN/EUR/USA) I try to boot from the start at 50HZ, the music is either messed up, or the sound effects are missing. If I switch it back to 60HZ on the fly the music gets fixed, but in some games I have to reboot the console and restart it at 60HZ.

This even occurs in various European PAL region locked games like Mega Swiv, Mega Turrican, Ranger X & Alien Soldier. If I switch it to 60HZ right after it passes the region lock, they all work fine at 60HZ, but if I revert them back to 50HZ, the music gets messed up.


The only games which I was able to run natively at 50HZ right from the start and switched between 50/60HZ on the fly without any problems, were Bare Knuckle 1 (JPN), Turrican 1 (USA), Bio Hazard Battle (EURO) & Battle Squadron (USA). While Strider (USA) & Sensible Soccer (EURO), even though they start off fine at 50HZ, if I switch it to 60HZ during play, the screen gets garbled up, but if I switch it from 60HZ to 50HZ on the fly during play they’re fine.


Is this is a known issue with modded Genesis 2 consoles @50HZ, or have I done something horribly wrong? Is there any way to fix this and make it more compatible & universal like the EURO PAL modded Mega Drive II?


Thanks in advance

 

So, I re-soldered everything and checked the wiring / soldering and it seems to be ok, based on this guide for the Euro PAL MD2:
http://www.mmmonkey.co.uk/mega-drive-2-2-regions-switch/

The problem persists and now I just noticed that the right audio channel is barely functional via RGB Scart Cable and only some sound effects are played from it even at 60HZ. (Its not a problem with the TV or the cable, as I verified it with another fully working un-modded PAL MD2)

I wonder if some capacitor/s blew up on the mother board in the process? I would hate hunting it down or changing all of them, as they're quite a few!

Well I'm out of ideas.

 

take some pics of your mods.

 

Here you go:

http://i1356.photobucket.com/albums...s/SEGA/Genesis 2 USA/IMG_1738_zps4fa3233f.jpg

http://i1356.photobucket.com/albums...s/SEGA/Genesis 2 USA/IMG_1732_zpscc0945f8.jpg

http://i1356.photobucket.com/albums...s/SEGA/Genesis 2 USA/IMG_1726_zps3c7341dd.jpg

http://i1356.photobucket.com/albums...s/SEGA/Genesis 2 USA/IMG_1721_zps1dcbb3fd.jpg

http://i1356.photobucket.com/albums...s/SEGA/Genesis 2 USA/IMG_1716_zps3cbfd8c6.jpg

 

Is the track connected to pin 46 properly cut?

 

Yes. From what I checked with a multimeter, the track has been completely severed.

I checked both switches and they seem to work function, connecting Pins 46 & 107 to ground & +5V accordingly.
Now when I boot any game @50HZ, after a few seconds the screen will go black and will re-appear either if I switch it to 60HZ or restart the console all together.

 

What is the number on the main ic? It maybe the same as a model 1 va7 which also has issues switching to 50 hz.

 

Hi, I was unable to solve the problem nor detect any damage on the PCB:

The main IC has this written on it:

SEGA
315-5487-01
FC1004
9314 ZFDE
Z53

 

B I N G O!

That is (more than likely) the problem.

If you go to sega-16 & search for the thread "has anyone region modded a gen 1 va7", I asked the question due to similar issues. Other guys tried it and yep, with that ic, it isn't keen on 50hz. Language is fine.

I since sold my Gen 1 va7.

 

I have a minor problem with a 1.8 Mega Drive 2 running at 60Hz. With Sonic 1 and Sonic 2 I get a horizontal pattern of small dots on the bottom left hand side of the screen (can post pics if needed). Audio seems to be fine and the language switch is working. I can't test with any other games as they are the only two I currently have!

Games are flawless (although crap!) in good old 50Hz.

Not a massive issue but wondered if anyone else has seen this before? I'm using an RGB scart cable BTW.

 

Is it just the very bottom row, as in a couple of mm? I get the same on one of my tv's, i just ignore it lol!

 

So, I read the thread on that other forum and it looks like the exact same problem, but no one offered a solution.

 

That is because there is no solution. The ASIC is not PAL compatible. Not even sure if you could swap it out for one that is (all my Sega manuals are packed away).

 

OK then. I'll pack it up and call it a day.

 

By the way. I noticed that this specific Genesis model, the right audio channel barely works, only some sound effects are heard from it. Same problem occurs either I connect it via RGB Scart or via Composite RCA (I have RCA modded it)

Is it some defective capacitor that needs to be changed like the video/audio problems that plague the Game Gears?

Any help will be highly appreciated.