dee fresco

I have a legacy TLA-715 color mainframe (VXI modules).&#160; I've had a TLA7E1 DSO (oscilloscope) module for years.&#160; Recently, after transporting the unit across town, I started to get a power-on diagnostic error that will not go away.&#160; I have a spare TLA-704 mainframe and the same error exists there ... so ... appears to be the module, not the frame.<br> <br> Control Voltage Serial Loop ... Fail<br> <br> Does anyone know what this failure even means?&#160; I'm suspecting a jolt in transport caused a solder lead to open, but cannot find it.&#160; Be nice to know what the &quot;Control Voltage Serial Loop&quot; connects to or controls.&#160; Maybe I could zero in better.<br> <br> It does not appear to keep the unit from working, but does keep it from being able to calibrate.&#160; Can't calibrate with a diagnostic error.<br> <br> I was thinking maybe the electrolytic capacitors could have failed (time) and some voltage is not properly in spec, but before I get into that mess, was hoping someone might have an insight to short cut me.<br> <br> Do schematics exist for these modules?&#160; Any diagnostic port on the module?&#160; I noticed an RS-232 port on the module (board level), but haven't investigated that for any possible diagnostic capabilities.<br> <br> Tnx.<br> <br> Dee