HP 8565c Intermittent Startup Woes

My older HP 8565c is having some troubles -- perhaps age or cable-related ones.
On occasion when the computer is turned off then back on it will only "beep." The monitor stays dark and it never reaches any of the bootup procedures.
While checking the connections on the sliding mechanism that holds the hard drives and CD player it turned out that sliding this out of the bay, then back in, would sometimes solve the problem and the computer would boot up correctly.
Does this sound like a cable problem? The computer is, of course, six years old and not worth putting much money into a fix.
Thanks for any advice.