Sega Master System isn't reading cartridges

[blipcs76]

I've got a Sega Master system (first model), that only loads the 'pick Hang On or Safari Hunt' screen when I pop in a cartridge and turn it on.  It did load a card game that I tried on it, but I tried several cartridges with no luck.

I assume this means I have a dirty/faulty connector in my system.  If that's the case, what's the best way to get them to read carts again?

[tripredacus]

Hopefully a dirty cart slot is all the problem, when it happened to me I had resolder the CPU.

[crabhammer]

If I'm correct in guessing, you may have the same issue that I just went through and fixed.

Grab a magnifying glass and check the solder joints under the cart slot connector. I found that I had about 75% of those joints cracked. It took no time at all to re-solder the joints and my SMS is running like new again.