I have had lots of experience with these RCA DLP sets. Apart from the Lamp and the Color Wheel issues, these RCA units are notorious for their defective power supplies. You will experience the same exact issue you are mentioning, which is the 5 time blinking power light (blue).
This normally entails an issue with the lamp in the instruction manual, however, this is very deceiving. The 5 blinking lights can be caused by one of the following issues:
1 - Lamp is Bad - Step 1 is to purchase a new lamp. I always recommend Philips brand just because the quality of the lamps for the price difference between aftermarket or 3rd party lamps is much more superior. You may save $20-$30 in the short run, but it will cost you lots of money and headaches in the long run. Discount-Merchant.com is my go-to site for my lamp needs because their prices seem to be much cheaper than PartStore (my other favorite) and you know you are getting original Philips product rather than a chinese copy or a refurbished lamp with just a Philips reflector and a generic burner.
2 - Check your color wheel - Step 2 is to open your TV and check the colorwheel. A great guide is available for color wheel replacements at http://guides.fixyourdlp.com/
... one of the reasons i started to post here is because the vast information on this site. Although the guide is for a samsung colorwheel, the process is the same. Make sure the color wheel rotates freely without any friction. At times, the wheel is shattered and you will notice your problem. Other times, the bearing has worn out and it prevents your CW from reaching the required RPM... The sensor on the color wheel housing will signal the DMD board to shut the TV off.
3 - Check your ballast / lamp driver - Step 3 is to listen to your TV. Does it make a click noise when you press the power button? If you get a single solid click, chances are your ballast is working (clicking on) and you may want to purchase a lamp to start out with. If you get multiple clicks, chances are your ballast needs to be replaced. First, unasseble the back of your TV (but tape the lamp door switch down) and press the power button. Your power supply should send 320V-380V to your ballast for at least a second or two. If the voltage is there and is greater 320V, your ballast is your best bet.
3a - Check your power supply - Step 3a is part of step 3. If your ballast is not receiving the voltage greater than 320V (sometimes you will get 280V or lower) this means that you have a weak power supply and that the power supply needs replacing.
Beleive it or not, the power supply on the RCA units fail MORE OFTEN than the ballast! It is the #2 most comon failing part on the RCA DLP tvs aside from the lamp. Before diging into other problems, buy a new lamp as this diagnostic may be un-nessecary and your problem may the THE MOST COMMON! The lamp!
I hope this helps are you guys with RCA's infamous 5 blinking lights.