I wasn't sure just what kind of caps these boards used for C4 and C5 so i just dug out an old Bally 35 mpu for a look see. These are tag tantalum capacitors and are notorious for shorting out.. i have replaced hundreds of these caps over the years in all kinds of electronic equipment... so definitely replace them BOTH ( C4 and C5). Just use good quality electrolytic caps of the same value. they'll work fine.