I found a broken Oscilloquarz OSA 5400 <http://leapsecond.com/museum/osa5400/1982-OSA-B-5400-ds.pdf> in the shelf. It draws only 3mA of current on power up. (heating element/reverse polarity failure?) Can anybody point me to schematics somewhere around? What are the typical failures from you experience? Thanks in advance. .marek