Sunday 1 April 2012

MY WORKBENCH THIS WEEK


Hi all,

Throughout March I've had to take 9 1/2 days off to use up my statutory holidays and I've been hoping to get a load of work done on my geeky Megadrive projects. Well with the weather being so hot and sunny nearly everyday I've been off work I did a bit more work outside. Helping in the garden, sorting out the patio we're going to be making at home and helping a mate out digging and laying a new path at his house I didn't get as much done as I was hoping.

What you can see on my work area is the Neptune case in the centre with yet more filler on it awaiting a coating of grey primer. A "lost cause" Megadrive 2 awaiting some resurrection on the right. On the left is the starts of a Jamma SuperGun. This arrangement shows the comparison of the new Neptune case next to the original MD2 case which is where it started from. :-)

Last sunday I picked up 2 Megadrive's and 15 games. The night before I got a message from the guy saying that one of the 'drives had stopped working so I got the lot at a more reduced price. I thought I'd give it a go at fixing the 1 megadrive as a learning exercise.

I opened up the case and low and behold its a VA0 board which is the first edition of the Megadrive 2. The first thing I noticed after that was man it was grotty in there! and also that the LED looked like it had exploded! That appeared to be the main contributing factor that the thing wouldn't turn on. I also noticed that the solder around the power socket had come away and the main pin was partially exposed. I changed out the LED and resoldered the power socket and the thing fired up!! HOT DOG!

I went up to our hobby room and plugged it in and got no picture. A little wiggle of the A/V cable and the TMSS screen (trademark security screen) buzzed into view then went again. It also had a damaged A/V port. This thing was really used to death it seems and not very well looked after. I just so happened to have a spare port from my 32x so I desoldered the damaged port and replaced it. Went back upstairs and a stable TMSS screen but then Sonic 2 wouldn't boot. :-( Poo sticks!

I then set about cleaning the cartridge slot as this is a well known problem with them not booting up. There was a heck of a lot of fluff coming out of there. Gave it a sand and then a clean with some cleaning alcohol. Still no boot! Dang it! The next step was me tickling around the underside of the board checking continuaity of all the capacitors and found 2 that didn't show a circuit on my multi-meter. I desoldered the 2 offending cap's and resoldered them to the board. The multimeter showed a circuit for both of them. Woop! This could be it!

A quick check and still no boot but still showing the TMSS screen! I was ready to give up on the thing and call it quits.

This morning I remembered that I had a spare Megadrive 2 cartridge edge connector from the Neptune and set about desoldering the old slot from the "lost cause" and replacing it with the VA2 one. It being a newer version slot would have a better chance of working as It worked on the Neptune Megadrive before it was removed. After a bit of to-ing and fro-ing of the desoldering and replacement it still didn't boot. Game Over!

I can pretty much conclude now that the thing must have been surged somehow which blew the LED and probably blew one of the more delicate components of the board. Oh well, my "restoration" of the "lost cause" didn't work. But, Man! I gave it a blumin good go. Check it out with its VA2 cartridge slot, 32x A/V port and Pimped yellow LED. I got it back from the dead so much that it would turn on and show TMSS but couldn't get it that little extra step to boot.


I gave it a real good college try but it wasn't to be. I was kinda hoping that I would get it up and running and have a machine to experiment with. Oh well. I still have the other MD2 as my next Neptune candidate though. :-)


As this is a long post I'll post up a progress report on my Neptune case which is in its final stages I think. :-)


Porl''