Related issues with HDMI have to do with the quality of the HDMI physical connections. These are mostly at the back of the top HDMI board on most Pioneer units. If you remove the top cover (side and back screws hold it on, then lift the back up, and pull up and out toward the back), you will see the top board.
You will see one HDMI cable going frontwards. Another responder here noted his HDMI connection was loose there. Try to tighten up that connection.
The side connections to that board are critical too. If the side connections are not tight, you may lose audio outputs. Try to pull those out and push back in.
If your HDMI signals ate noisy or HDMI video fails, I have also had to remove the top board to slightly re-compress the back HDMI surround ground shield. When an outer metal connection jacket gets bent open, the HDMI internal pins may lose good contact. The external shields can be gently compressed with a settable clamp, or pliers (the ViceGrip brand has an adjustable bolt in back to limit the jaws distance, and works well). Be very careful not to break any of the tiny soldered components under or near those back HDMI ports. Then reassemble the top board into the chassis and be very sure the side connectors are well inserted.
With luck, your Pioneer receiver will be fully operational and it's audio and HDMI back to full function.
-Michael