Anyone with Cipher F880 experience?

I have a DEC TS05 (re-badged F880 without high-density mode; otherwise same PCB and everything) which is poorly behaved. Before I go diving in with the maintenance manual, is there anyone on here with experience repairing F880s? Symptoms: - It occasionally just resets (especially once it gets warmer). I'm willing to bet this is a flaky regulator somewhere, but I don't have a digital scope to see the transients very well. - When loading (and occasionally during operation, if it ever gets that far), it bugs out with either a compliance arm or tachometer error. Both of the superficial diagnostics for the compliance arm and the tachometer indicate no problems, so I'm assuming it's a problem somewhere in the logic. It only successfully loads maybe one time out of 20, even when I load it pre-threaded (1 out of 3 when it's cold, but it doesn't stay that way for long), which makes the first problem all the more irritating. - Dave