Pioneer T.V. review: Stuck in Standby mode 1

We own a Pioneer Plasma pdp r04u. For the past several months when watching t.v., the fan in the media receiver is noisy. You can hear it over the t.v. My husband took the lid off of the media receiver to clean out the dust, hoping that would solve the problem. When he put the lid back on, the t.v. was stuck in standby mode. He couldn't figure out why it wouldn't work. He went online and found that several people are having the same problem. Pioneer put a trip switch in the media receiver so if the lid is taken off, you need a code to reset the receiver.
We cannot find the code anywhere. T.V. specialists online want money to give you the code. So ridiculous. I was hoping by posting this, someone may have experienced the same problem, and have the code already. Please share if you have it.
It really upsets me, when companies do things like this, so they can make more money on repairs.