I disconnected my ps3 from a hdmi connection with out changing the output settings?

May be...

now i hooked up to a regular av jacks tv and i cant hear or see a thing was i supposed to switch the setting or were they supposed to change by itself ...thanks in advance

With the PS3 off, hold the power button on the console for 5-6 seconds (the console will beep twice during this timespan). This resets the display settings to the A/V cables.

Just reset the unit, do a power down on the (_I_) switch then cut off the power on the switch in the back for about a minute or two, then turn it back on. Make sure your tv is also on the AV setting.

just press and hole the power button on the front of the playstation and it should reset it self to the av components

hold down the button until the 2th bip when you start the ps3