Replacing the VRAM in Mega Drive 2 serial 440005313 didn’t solve the issue, but boy did I have fun doing it! And that’s what this YouTube channel is all about: Fun! (or was it chaos?)

This particular Mega Drive 2 had been suffering from intermittent video problems and illegal instruction errors. I’d originally considered turning it into a circuit-bending experiment, but then discovered I had a spare RAM chip from another water-damaged Mega Drive. Might as well try replacing it first!

Getting the old chip off was an adventure in itself. I tried using a piece of wire underneath the pins while heating them with the soldering iron, but that wasn’t going particularly well. In fact, I was mostly bending the legs. Out came the hot-air gun instead.

Once the old chip was off, I had the replacement ready to go. A little flux, a lot of patience and a reasonable amount of fiddling with the chip’s position. I made sure the notch was facing towards the cartridge slot before securing it in place.

The real entertainment began when I tried to solder all those tiny legs. I tacked the chip down, including pins 20 and 40, which are the ground and supply connections mentioned in the video. Then I added some more flux and started working around the remaining pins, clearing the inevitable excess solder with desoldering braid. There was quite a bit of it to clear, too.

Some pins were nicely attached while others were still looking rather suspicious. I could certainly understand why people charge so much for this sort of component-level repair. It’s easy to get yourself into a spectacular mess if you aren’t careful.

Eventually I had enough of the pins connected to give the Mega Drive a test. I thought I’d try Sonic the Hedgehog, because what else would you test a Mega Drive with? The result was magnificent. White screens, blue screens, black screens and just about every other shade of not-working I could imagine. At least the console was producing a picture of some description!

Back to the soldering iron, then. After some more work cleaning up the connections, Sonic finally started running. There was a Sega logo, proper gameplay and everything appearing rather more normal than before. Much better!

The soldering itself was certainly looking tidier by that point, although there were still a few areas I wanted to inspect more closely. I’d managed to remove and replace the VRAM chip without destroying the board, which was quite satisfying in itself.

Unfortunately, the original intermittent video fault wasn’t permanently resolved by the VRAM replacement. A successful game test was encouraging, but this particular machine had been misbehaving sporadically from the beginning. It could seem perfectly fine for a while before the problems came back.

I’d also been considering swapping the video encoder, so that remained another possibility to explore. In fact, with a spare chip available from the water-damaged board, it was tempting to keep experimenting.

Of course, if I accidentally fixed the Mega Drive completely, that would ruin my original plan to turn it into a circuit-bending machine. What a dreadful outcome that would be! Still, replacing the VRAM had been a worthwhile exercise, even if it wasn’t the answer to the fault I was chasing.

At least I got another opportunity to practise soldering those tiny surface-mount chips. More investigation required for serial 440005313, I think!

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