Tektronix 2445A - glitches

[c4757p]

I just bought a used Tektronix 2445A oscilloscope to replace my crappy analog scope. It seems to be in great condition, but I was wondering about a certain problem. On the on-screen readouts, some characters (notably O and Q) are missing pixels, and on the trigger frequency display, the "z" in "Hz" is missing (yesterday it was blinking, now it's gone). Should I consider this a sign that there is a ROM/RAM/something about to fail, or just something that needs to be reseated? And if it does fail, how far up the proverbial creek will I be regarding replacement? The service manual has very extensive troubleshooting guides, but none of them mention something like this.

[c4757p]

Hmm... Shortly after I posted this it started going crazy. Error messages all over the shop and a garbled readout. I used the "screw troubleshooting" method and completely disassembled and reassembled the entire scope. Works great now.