Non-working Genesis cart...

[Tupin]

So, I found a complete Ms. Pac-Man for Genesis for $3 at Goodwill, but the cartridge did not work, even though it appeared to be in good condition. So I went down to a store that sells Genesis games, bought a used one with a terrible label, and swapped out the boards.

It worked, but I'm curious what could possibly make it not work. I'm thinking it's a blown fuse or capacitor or something. I think it would be a pretty easy solder, but I'm not sure.

[evildragon]

You did try cleaning the cartridge, right? ;) The contacts.

[VACRMH]

Seems genny Tengen games seem to have problems not working sometimes. I had a DOA Dragons Revenge myself.

[Tupin]

You did try cleaning the cartridge, right? ;) The contacts.
I practically used an entire bottle of alcohol.

The contacts are clean.

What are the fuses/transistors I need?

[Wraith Storm]

I practically used an entire bottle of alcohol.

The contacts are clean.

What are the fuses/transistors I need?

I have about 8 used games stores in my area and for the past 5 years that I have looked I have only seen ONE copy of the original Sunsoft Batman for the Genesis. When I came across it, I looked it over and it seemed to be in MINT condition. I snapped it up but when I got home It wouldnt work.

I tried it in my CDX, X'EYE and Nomad and it wouldn't play in any of them. I even took it back to the store and of course they didn't have another copy but they gave me a refund and cleaned the game for me and let me keep it, however it stil wouldn't play.

I have often wondered about why it won't play as well... It just sits on my shelf and taunts me.

[evildragon]

ROM chips do fail ya know. ;)

[otaku]

I just bought a copy of gaiares for genesis that is in need of a cleaning (hopefull y that is all)

[Bratwurst]

Believe it or not, I have had a handful of Genesis carts come my way that refused to work, and when I inspected them, found that one or more points on the circuit board had been joined by stray solder. Once I cleaned up the obvious errors they booted up just fine.

When in doubt, check the inside for any points that have solder bridging between them that shouldn't be. A giveaway for stray solder joints are two points bridging on the board that don't share a printed trace underneath or on the other side.

How this happens, I can't say for sure. Poor quality control, failing to catch a non-working game before it was shipped to retail, or perhaps a point on the board was given too much solder and the game got hot enough during use that a connection happened to an adjacent pin due to just enough solder flow. I've seen quite a few Sega boards with excessive solder blobs on a chip's pin, and to be frank, the actual build quality of their products is a step behind Nintendo's.

[Tupin]

I'm seeing blobs of solder on holes where they didn't even solder anything. It's like they drilled a hole, realized their mistake, and then filled it in with solder.

That probably doesn't matter, but the solder on the entire thing is uneven and globby.

The capacitor is made by Elna and has 6v 47uF and 16 v47 written on it, but I'm not sure if that is the voltage or what.

[jb143]

I used to repair boards at work and sometimes had to use a microscope to see the little solder balls that would be bridging traces. In this case it was caused by the wave soldering process, tiny bits of solder would jump up and could eventually get lodged in just the right place...usually between pins on a chip.

It sounds like some carts are failing becasue of shabby manufacturing.

If you want to replace the cap, which is more likely to go bad than the rom, then replce it with pretty much any 47uF cap that is at least 5V. And make sure the polarity is correct.

The holes that are filled in with solder could be a conection through the board. Or just a dot of solder stuck to an empty pad on the board. Mass produced boards aren't hand soldered, they're skimmed over a vat of melted solder(wave soldered) or even baked in a special oven if they're surface mount parts.

[Tupin]

I used to repair boards at work and sometimes had to use a microscope to see the little solder balls that would be bridging traces. In this case it was caused by the wave soldering process, tiny bits of solder would jump up and could eventually get lodged in just the right place...usually between pins on a chip.

It sounds like some carts are failing becasue of shabby manufacturing.

If you want to replace the cap, which is more likely to go bad than the rom, then replce it with pretty much any 47uF cap that is at least 5V. And make sure the polarity is correct.

The holes that are filled in with solder could be a conection through the board. Or just a dot of solder stuck to an empty pad on the board. Mass produced boards aren't hand soldered, they're skimmed over a vat of melted solder(wave soldered) or even baked in a special oven if they're surface mount parts.
By "making sure the polarity is correct" do you mean inserting and soldering it correctly?

These caps can be bought at places like Radio Shack, right?

[jb143]

At 47uF I'm assuming it's an electrolytic cap which has a positive and a negaive lead(sually there's a '-' onthe negative side). If it's soldered in backwards then there's a good chance it will blow and you'll have to replace it again...and maybe clean the board again too.

It's a pretty common part, Radio Shack should have it. If it's what I'm thiking it is then it will probally cost a bit over a dollar from them.

Does it look like anything has seeped out? Does it look busted or bloated even a tiny bit? Without looking myself it's hard to diagnose if that's what the problem would be.

[Tupin]

Here's a picture:

http://i186.photobucket.com/albums/x28/TUPPYLUVER95/IMG_2029.jpg

It IS a little flayed up. I'm going to replace it, it looks like a pretty easy fix.

[jb143]

Yeah, that should be super easy to replace. It's hard to tell from the pic but it looks like the top puffed up some...It should be flat.

There's a small chance that the cap was put in backwards at the factory and it escaped testing (I've seen it happen) If that's the case then check to see if the negative terminal has electrical contact with the big copper ground plane that runs around the outside of the board. It may not suposed to but if the positive terminal does then it's a dead giveaway that it's wrong. If you'd like I can try to check mine when I get home. Which I also got from goodwill for $3.00

[Tupin]

Yeah, it's puffed up at the top.

You also got a non working Genesis game at Goodwill for $3?

This would be a good replacement, right?

http://tiny.cc/xCZoX

[jb143]

Mine's a working one.

It looks like that one's 4700µF. Make sure the one you get matches what's in there. Also, watch the phisical size, there should be enough room in a genesis cart but it would be bad to replace it and not be able to screw the case back together all the way.

It also costs a bit much but that's just Radio Shack. If it's 47uF then you'll probally want something like this (http://www.radioshack.com/product/index.jsp?productId=2102512&cp=&sr=1&kw=capacitor+47f&origkw=capacitor+47%C2%B5F&parentPage=search).

btw...I just checked our cost at work and we buy the part for 3 cents...we buy 1000 at a time though.

And since I usually direct people away from Radio Shack...At digikey (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=P957-ND) you can get 10 for 84 cents...but in this case since you just need the 1 and may not ever do a repair again, Radio Shack should be fine.

[Wraith Storm]

Hmmm... This has me curious. I think i'm gonna crack open my Batman cart and see if I can find anything out of the ordinary.

If something does need to be soldered this looks like an easy project to hone my non existant soldering skills. :p

[Tupin]

It doesn't look like that, the capacitor in the cart is long and blue.

It says 16v 47uf.

[Tupin]

I'm pretty sure the first one I pulled up on Radioshack that cost $5 is the one I need...

[jb143]

The link you gave took me to a 4700µF capacitor.

[Tupin]

Yeah, but it looks like the one in the cartridge and even has the same markings.