Leader LG3236 - No output over 100dBu - Unidentifiable SMD Part 1.

[ratlordfx]

Hi there,

I recently bought an LG3236 off of ebay, and everything worked fine except for the output signal dropping as soon as I hit 101dBu, right when the relay kicks in.  I had it open to clean all the controls, so I figured I would dive deeper into the RF output section.  I opened up the shielded enclosure, and traced the signal back from the output.  I noticed that when the signal hits 101dBu, it gets switched over from a bypass bus line to run thru some amplifier circuitry.  I also found that the signal drops out after reaching U1, a small round 4-pin smd labelled "1."  I measured this part and it has a very low resistance, but I cannot find any info about it. 

Can anybody help me identify this part?  I also suspected that the rf amplifier RF2317 is bad, but I'm not sure.

Any help is much appreciated

Thanks,
ratlord