Panasonic PT-50LC13 AV switching problem

Several of the AV inputs/outputs of this set do not work:
The tv tuner audio works but no video (does going into switching circuit though).
The HDMI and 2 component inputs work (video and audio). The front panel card reader and computer RGB works. No SVideo output.
There seem to be two related AV switch IC's. I replaced one (IC3501) with no change and cannot find a source for the other(IC3602 cxa2069q). There is a service menu to test I2C communications to the various IC's - I do not get a response when I press the remote. I am not sure how this menu section is supposed to work. Anyone familiar with diagnosis of this set that I can privately (or here) email with? Voltages to video boards look good. I have schematics and service manual. The key is to understand the I2C service check and see if IC's give a response. The set works as an HDMI monitor now just fine - with great audio. Don't want to risk trashing it on faulty repair screw up unless I know for sure what to fix.
Also the set has one darn stuck pixel just to annoy me....