Radio Shack CID 2903 - Manual (Page 30)

30 Troubleshooting
CARE
Keep the CID dry; if it gets wet, wipe it dry
immediately. Use and store the CID only
in normal temperature environments.
Handle the CID carefully; do not drop it.
Keep the CID away from dust and dirt,
and wipe it with a damp cloth occasionally
to keep it looking new.
Modifying or tampering with the CID’s
internal components can cause a
malfunction and might invalidate its
warranty and void your FCC authorization
to operate it. If your CID is not performing
as it should, take it to your local
RadioShack store for assistance. If the
trouble is affecting the telephone lines, the
phone company can ask you to
disconnect your CID until you have
resolved the problem.