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