NES cart repair

[Trimoor]

I have a gold edition Zelda NES cart I bought from a garage sale, but it doesn't work.  When powered up, the NES displays a solid gray screen, and the LED is not blinking.  The cart is in great physical condition with clean contacts and a fully charged battery.  The NES works with every other game I have.

What could be wrong?

[Daniel270]

slightly off topic...

how did you get the battery changed?  I've got several carts I've had since brand new that use batteries and have NO idea what tool is necessary to open the cart up without damaging it....

[Trimoor]

I didn't change the battery, just tested it with a meter.  To open it, I originally filed a notch in an old screwdriver.  This barely worked, but now I have a full set of security bits I bought from some computer store which I can't remember the name of.

I have heard rumors about using a bic pen casing to open it, but the best thing to do is buy an NES security screwdriver from ebay.

[shmokes]

The pen thing works really well to open gamecubes, because they fit in the hole, but might be too big for a cartridge.  At any rate, it does work, and pretty well and you can apply the concept to work for you, even if you have to find another piece of plastic other than a big pen.  Here's how it works.

Heat up the end of a big pen with a lighter, so the plastic end cap becomes very soft (you don't want it to be liquid, but pretty soft.  Now press it into the screw and it will mold itself around it.  Hold it there until the plastic cools and hardens and now you can twist out the screw.  The great thing, is that you can usually just pull it off the screw and it will retain it's shape and they are surprisingly durable.  So you don't have to do this for each screw, just for the first screw.  After that you will have your own custom screwdriver for the security torx screw thingies.

[ChadTower]

What could be wrong?

Check for cold solder joints on the game pcb.  Hell, reflow them all, there can't be more than ten minutes worth there.

[Trimoor]

I reflowed the joints, scrubbed the contacts and cleaned the system.  No change.

I noticed that only half the vias have solder in them.  They have copper cladding, but it seems odd they would solder half of them.  (Unless they use wave flow soldering, then it would be left to chance)

Any other ideas?

[SirPeale]

Maybe the cart just doesn't work.

[Trimoor]

That's what I'm trying to fix.

[ChadTower]

It could be that Zelda uses a pin that none of your other games do and your NES has a bad one in the connector.

[Zakk]

Just buy a new one, they are cheap 

Ebay Link



Edit by moderator: please, shorten long URLs!

[ChadTower]

They are also unreliable.  There are three sources for new NES connectors:

MCM - terrible.  Probably 30% of them have bad pins (read - some games will NEVER work with it).  Their tension is 3-4x the OEM tension and you have to literally use pliers to remove games with thick PCBs.

Don't know the Manuf - These are labeled "Gold connectors".  They have a gold plating for better connection.  A VERY THIN gold plating that is useless and wears off quickly.  These are a little better, and a lot rarer, than MCM.

Simple Jet - These are pretty much only available through one guy, in lots of at least ten.  The guy is Omnedon and hangs out on the forum at digitpress.com.  They are the best of the three sources, though I have a lot of ten and am still having less than 100% reliability.  By far the best of the three, however, and I can personally vouch for the guy's reliability.

I've literally done 20-30 of these things.  The best way is to take some fine grit sand paper and sand down the pins on an OEM connector, then clean with alcohol.  Keep repeating until you get to 100% reliability.