Batboard

Hello all. I recently picked up an R-2200B service monitor. All GEN functions appear normal. There is no audio from the speaker in any mode. In RX mode, the monitor will read power input and frequency error, however the deviation meter overloads and I do not believe the scope is seeing clean audio, although it IS seeing voice. The Sig Lvl led is on all of the time. I do not have a service manual for this monitor yet, and would appreciate any help walking through some initial troubleshooting. I did remove the RX antenna connector to check the internal fuse, and did not find one. It was suggested to me that this monitor may have had RX input in excess of its limit, however I do not know which port.

Update... Located bad speaker which corrected no audio problem. Re-seated RX, audio, and front panel interface cards which corrected open squelch resulting in "sig lvl" light being on. Now.. Generating a 1'kz tone shows a nice clean sine wave on the 2200B's scope. When trying to receive a 1khz tone from my IFR 1200, the scope display flickers, and shows a dirty/raspy sine wave (output from my 1200 is clean). So I have ruled out a bad scope because I believe it would exhibit the same display issues in the GEN mode. Has anyone else experienced this?