It could be that you don't have the cable plugged into the correct spot on your TV. If you are using the AV cable that came with the PS3 and not a Component PS3 cable 2 of the RCA plugs go for sound and only one is for Video. The AV cable that came with the PS3 is not for a HDTV connection and the settings need to be corrected. While you said you changed houses you must have also changed TV's or you would not have needed to switch from HDMI. If your new TV is an HDTV then you need to purchase a PS3 component cable if it doesn't have HDMI plugs and if not you need to change your settings on the PS3.
To set the PS3 setting on the PS3 back see the PlayStation Super Secrets link which I have clip and pasted below:
Hold Power button down for two beeps (while PS3 is off): Reset video to lowest settings.
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The AV cable that comes with the PS3 is not for HDTV set up. You need to purchased a HDMI cable or a Sony PS3 component cable and then it should work.
The Sony Component AV Cable will fit the PS3 super slim model.
first choice HDMI. You should only get Sony PS3 component cables if you HDTV does not have HDMI input
because its not connected correctly but ps3 always break
Your remote works on a different system than the Bluetooth the PS3 uses. The HDMI sync on my slim PS3 ( Fat PS3s lack the hardware for HDMI Sync) allows me to use my Sony HDTV Remote and also my Sony Home Theater Remote even though they are not Bluetooth to control the Playing of DVDs and Blue Ray Discs and the selections from the PS3 menu bar. I can not sync my Cable remote to do anything on the PS3 even though I can get it to work some features for the Home Theater and HDTV If you want to sync the PS3 optional remote you need to plug it in to the PS3 with the charging cable to get it to sync with the PS3