SMS Sega Master System Console problem

[loporjai2003]

Got a SMS that is behaving odd.

I verified RF and PS is good on another system.
If you power it on without a cart you get the Sega
screen and instructions.

Sometimes (not all the time), if you put a cart it and power it up, you get a blank black screen and an annoying buzz sound.
Powering off/reset does seem to help and I have to pull
cart out power on again without cart to get rid of the buzz sound.
Putting cart back in it will sometimes work, other times
more blank screen and buzz sounds.

I have cleaned all carts and the connector thoroughly so it can't be dirty contacts.

Any ideas ?

[omnedon]

Maybe cold solder joints on the cartridge slot?

[loporjai2003]

Maybe cold solder joints on the cartridge slot?

Close ... opened sucker up and it was a repaired one, wire traces where the board trace flaked off etc .. found loose cap connection. Also cold solder on 2p control port.
This thing is frankenstein, I replaced the PS and RF connectors previously.

It lives !!

Thanks for the assist.