Joe,
C1258 could be bad. Mine is film. The original is electrolytic. Parts to the right of this part, in the schematic, are the things to check. Things like VR1258, d-c restorer diodes, preset pot open, R1245C/D open, bad solder joints, etc. look to be the problem. Check voltages at each end of the preset pot and wiper. If any of the d-c restorer diodes are bad, use 1N4937 diodes to replace them. Remove and reseat the connectors. A dirty connector can cause problems.
Mark
