Manuals / Telex / Home Audio / Stereo Amplifier

Telex MCE325 Preventive Maintenance, Factory Support Information, Corrective Maintenance

Models: MCE325

1 85

Download 85 pages 25.05 Kb

Page 39

MAINTENANCE

S E C T I O N

MAINTENANCE

Preventive Maintenance

Clean the unit and verify its performance periodically.

Factory Support Information

Factory support information is located on the first page of this manual.

Corrective Maintenance

WARNING: Hazardous voltages exist inside the MCE325. Attempting diagnosis, repair, or adjustment with the AC line connected could result in serious injury or death. These servicing instructions are for qualified personnel only.

Access

1Reference the AS6464 drawing in section 6. Remove the four long screws (item 4) and the two short screws (item 5).

2Lift off the top cover.

3Pull the front panel slightly forward to clear the carbon mic jack on the main circuit board. Lift the front panel slightly while sliding the back panel toward the rear and out of the lower case. The MCE325 may now be operated for troubleshooting.

NOTE when reassembling the bottom cover, make sure the rubber button on the inside of the bottom cover (item 7) is toward the front of the unit.

Front Panel Removal

1Unplug the panel mic (J1) and dynamic-mic headset (J2) connectors from the main circuit board.

4-1

Image 39

Telex MCE325 Preventive Maintenance, Factory Support Information, Corrective Maintenance, Access, Front Panel Removal

Contents

MODEL MCE325 USER INSTRUCTIONSPROGRAMMABLE USER STATION UNPACKING AND INSPECTION WARRANTY INFORMATIONPROPRIETARY NOTICE COPYRIGHT NOTICERETURN SHIPPING INSTRUCTIONS End-UserLicense Agreement for Telex Software TABLE OF CONTENTS Description & SpecificationsInstallation Operation MaintenanceDiagrams Parts ListsPage General DESCRIPTION & SPECIFICATIONSFeatures DescriptionChannel Selector and Operation Buttons Front Panel FeaturesVolume Controls Connections, Inputs and OutputsRear Panel Features Intercom LinesExternal Program Input Programming PowerMounting Configuration Auxiliary ConnectorHeadphone Amplifier MCE325 SpecificationsPower and Mechanical Microphone PreamplifierConnectors MCS325 SpecificationsFigure 1.3 Standard four-channel, two-wireconfiguration 1-8 M C E 3 2 5 U s e r I n s t r u c t i o n s Figure 1.8 Multiple interconnected stations using one four-wireintercom channel and two two-wirechannels for IFB’s 1-10 M C E 3 2 5 U s e r I n s t r u c t i o n s Figure 1.11 MCE325 button configurations 1-12 M C E 3 2 5 U s e r I n s t r u c t i o n s S E C T I O N INSTALLATIONInternal Programming and Adjustments GeneralFigure 2.1 Top cover removal Switch NumberSwitch Function Default SettingJumper Function Table 2.2 Jumper functions and default settingsDefault Setting Jumper Number2-4 C S I - 2 0 0 U s e r I n s t r u c t i o n s VOX DS8 Front Panel Setup Mode Lock-outDS4ISO DS5 Remote Talk-offDS7Program Assignment - IFB Option J4, J5, J16-J18 Mechanical InstallationHeadphone Sidetone Trimmer Adjustment R37 Speaker Dim Adjustment R157Figure 2.3 Mounting configurations Four-wireOutput Termination Electrical InstallationAC Power and Fuse Connector Pin-outsExternal Speaker, J27 Auxiliary Connector, J22Four-WireChannel A and B Input Program Inputs, J14 and J15External Headset Remote Microphone SwitchKey outputs - Expanded IFB Option ISO ConnectionExternal Electret Microphone Front Panel Headset ConnectionsUnswitched Microphone Output External DC Power SourceCarbon microphone Table 2.9 Carbon-microphoneheadset connectorSECTION FUNCTIONOperating Instructions LED IndicatorsOPERATION GeneralMicrophone On/Off Volume AdjustmentFront Panel Sidetone Nulling Trimmer Adjustment Panel Mic/Headset Mic SelectionMenu Selection/Ending Setup Sending and Receiving Call SignalsUsing the Talk-OffFeature Activating Setup ModeFour-channelListen Call DisableLatch Disable Channel IDInstant Mic Reset3-6 C S I - 2 0 0 U s e r I n s t r u c t i o n s Access MAINTENANCEPreventive Maintenance Corrective MaintenanceTest Equipment Test and Adjustment ProceduresCleaning Power Supply TestKeying Output Test Initial ConfigurationFrequency Response and Level Check, Mic to Line Four-Channel, Two-WireModeTwo-Channel, Four-WireMode Sidetone Null Test and AdjustmentTrue Sidetone Adjust Program A to Left Headphone IFB B IFB TestProgram B to Right Headphone Program to SpeakerFour-WireA Input to Left Headphone Four-WireB input to Right HeadphoneIFB A Mic Kill Receive Test Panel Mic to Channel TestCarbon Mic to Channel Test VOX TestMic Kill Transmit Test Call Transmit TestCall Receive Test Noise Checks Remote Mic Switch TestISO Test Program Lockout Test15Turn all buttons off Page S E C T I O N PARTS LISTSPackaging Assembly Final Assembly, MCE325Description Front Panel AssemblyTable 5.3 Reference AS6261 Drawing, Section Item NoItem No Back Panel AssemblyHeatsink Assembly Main PC Board AssemblyC104 Capacitor, EL, 10µF Capacitor, Mylar, 1nF Diode, 1N4004 Transistor, 2N5210 R170 R267 Resistor, CF, 22K Ohm, 5%, 1/8W IC, Dual Low-noise Op-Amp,NE5532N Description PC Board Assembly, Front PanelTable 5.7 Reference AS6246 Drawing, Section Ref NoPage S E C T I O N DIAGRAMS6-2 C S I - 2 0 0 U s e r I n s t r u c t i o n s Date 7/23/01 Title D \TEMP\AS6246 01B.calTime 05 20 45 PM Title D \TEMP\AS6245 01D.cal Time 05 27 24 PMDate 7/23/01 Title D \TEMP\AS6261 01C.cal Time 05 21 25 PMDate 7/23/01 Title D \TEMP\AS6262 01C.cal Time 05 22 16 PMDate 7/23/01 Date 7/19/01 Time 02 05 07 PMTitle C \home\cms\benedil\view\9020-6324 01.DWG Title D \TEMP\AS6464 01G.dwg Time 05 23 05 PMDate 7/23/01 Title D \TEMP\BD6464 01A.cal Time 05 23 33 PMDate 7/23/01 Title D \TEMP\IS6718 01A.cal Time 05 24 13 PMDate 7/23/01 Title D \TEMP\OD6355 01A.cal Time 05 24 51 PMDate 7/23/01 Title D \TEMP\OD6355 02A.cal Time 05 25 30 PMDate 7/23/01 Title D \TEMP\OD6355 03A.cal Time 05 26 07 PMDate 7/23/01 Title D \TEMP\OD6355 04A.cal Time 05 26 42 PMDate 7/23/01 Title c \home\cms\benedil\view\9000-6464 01.CAL Time 05 03 09 PMDate 7/23/01 9027624501 SCHEMATIC DIAGRAMMOTHERBOARD MCE325Title MOTHER BOARD9027624501 MCE325DWG. NO MOTHER BOARD MCE3259027624501 TitleTitle D \TEMP\SD6246 01A.cal Time 05 19 08 PMDate 7/23/01