Pioneer VSX-808RDS IR problems (Was: Testing an I.R. Receiver)

[Old Sparky]

I've now fitted a new 4Mhz Filter and checked/re-soldered the battery terminals. Remote still not working! Next step, I guess, is to rig up a 3v DC supply, so I can power the remote with the covers off, so I can connect either a 'scope or Freq. counter to see if there is 4Mhz present. My variable bench PSU only goes down to ca. 5.5v. I built it many years ago to a design in PW, and could modify it so it goes down to zero volts (as does my other, 10Amp PSU), but it's a time and inclination thing. Too much else to do!