I have a black screen when I connect the HDMI cable. When I connected it originally it worked for about 5 minutes but now I get nothing but the black screen. I tried connecting a different HDMI cable to it and I have the same problem. I have tried waiting 10-15 minutes before restarting and have also tried the reset by holding down the start button for 5 seconds for the 2 beeps. Nothing seems to be working. Please help.

The main reason of HDMI black screen problem due to HDMI cable may damage and not proper connected to the PS3 console. Please follow below step to troubleshoot PS3 HDMI cables problem:1) Restart your PlayStation 3.
2) Look for loose cables.
3) Try to unplug all cables except the power cord, and plug them back in. If you found out that your HDMI cable is damage, do borrow your friend cable and have a try. If your friend cable work fine, and the black screen error disappear. Then you can buy a brand new HDMI cable for replacement.
Tips 2: If tips 1 not working, you need to go another step deeper by reset your console. Most of the PS3 gamers not aware that Sony actually done include in the black screen troubleshooting method and other HDMI problems in the PS3 manual, you can find it under troubleshooting section - topic "console reset".
If you do it correctly, the console reset fix will allow you to reset back your PS3 to its default HDMI settings without impacting your gamer profile, and other storage data in hard drive.
You will need to perform the following steps:

1. Place your PS3 in stand-by mode.
2. Hold down the touch power button until a series of beeps are heard.
3. Listen for one long beep, followed to two shorter beeps.
4. Release the power button.
5. Follow the instructions on screen.