Plymouth, WI
At least 90% of all STTNG issues are the result of opto problems. Usually it's in the trough, but the ones down in the subway can also lead to craziness. Sometimes cleaning them (glass cleaner on a cotton swab) will do, sometimes it's a bad solder joint, sometimes the actual opto is bad. Mine once had a very intermittent issue with the optos that was actually caused by the crappy IDC connectors going to the board. The wire was severed partially through by the IDC. I ended up replacing that connector with crimp style and haven't had an issue since.
Either way...it always seems to come down to something with the optos.
