bryanr01: If neither of them has the codes for the other built-in, and neither is a learning remote, you're shopping for a new remote.
With a couple possible caveats:
From this thread:
[Link: remotecentral.com]On 12/15/00 09:23.38, Mike Riley said...
The new RM-LJ304 can learn some commands from other remotes, but only a few, and not to individual buttons.
Having no experience with the RM-LJ304 I don't know exactly what Mike means by "not to individual buttons" - It would seem to me that if a remote learns, it learns. The Sony remote would know that you're teaching a PIP command to it's mute button? That's highly evolved, and a PITB.
I have a Sony Rem. Cmmdr. that has a "search" feature. Even if you use the built in codes and fail to control a certain component you may be able to use "search" to get up and running. You toggle to the the component you want to control (VCR, Cable, TV are the examples given.) and press the "search" button and then the power button. Alternate between "search" and power until you get the power to come on.
From the Sony instructions: "Be patient as you do this; it may take 40 or 50 tries before the correct code number is located."
You're not out of the woods once you manage to power up the device; you still have to test to see if you've got volume/channel up/down etc.