Further information90eud-0850/2.1 — I7.7 — 10.2008TroubleshootingThis section contains a few tips on how to operate your phone if you encounter any problems.■ MalfunctionsYour call partner cannot hear you or you cannot hear your call partnerMake sure the handset cord is correctly plugged into both the handset and the phone (see chapter"Installation and First-Time Operation", page 92).Handset off-hook, no dialling tone, no displayMake sure the phone cord is correctly plugged in to both the phone and the LAN socket (see chapter"Installation and First-Time Operation", page 92).Display reads "Not configured", handset off-hook, no dial toneYour phone has not been assigned a call number. Contact your system administrator for more informa-tion.The display reads: "Trying to register"The telephone cannot be registered. Contact your system administrator for more information.Display is working, but connection is not possibleYour phone may be locked. Unlock your phone (see chapter "Unlocking Your Phone", page 40).Freely configurable keys cannot be configured.The configuration may be locked. Unlock your phone (see chapter "Unlocking Your Phone", page 40).The key for a reconfiguration may be locked in the system. Contact your system administrator for moreinformation.The expansion key module Aastra M530⁄M535 possibly has not sufficient power supply. Contact yoursystem administrator for more information.Insufficient display contrastThe setting for the display contrast is inadequate. Change the setting (see Chapter "Setting the display",page 56).Impaired sound quality during hands-free operationThe sound quality can be affected if the volume is too loud – turn down the volume. If the sound qualityfluctuates, contact your system administrator.Note:For all other messages, faults and questions you may have, contact your system administrator.
