Radio Shack CID-2904 - Manual (Page 26)

26 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 invalidate its warranty. 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.