[Collins] 75A-4 intermittent S meter

[K2DP]

The S-meter on my A4 has become very intermittent and typically now drops to 0 after
a few minutes (typical of a capacitor charging or discharging). Rotating the
function switch from the the STBY(normal operating position) through "on" to
"Cal" and then back to STBY brings the S meter back to life for a while
until the capacitor either charges or discharges ( I haven't dug into the
schematic and circuit yet). Has anyone experienced a similar problem and if so, can you point me in the right direction as far as suspect components , ie:which cap or caps are the likely leaky suspects to be replaced.

Any help would be appreciated. Thanks to all in advance.

73 and best regards,
Dave, K2DP, St. Louis