b&k precision 820 capacitance meter inop

[Napalm2002]

Hello everyone,
I was using my beloved 820 capacitance meter and I needed to change batteries.  However being tired I didn't pay attention to the sticker directly on the battery compartment stating that the unit may receive internal damage if batteries are installed incorrectly.  Can anyone help me try and fix this thing. I have no manual or schematics. 

Thanks

Mike M

[tautech]

This should help:
http://www.ko4bb.com/Manuals/09)_Misc_Test_Equipment/B&K/B&K_Precision_820__Capacitance_Meter__Service_Manual.pdf