QSC K.2 series Service Manual

3
TD-001517-01
K.2 Series Service Manual
Table of Contents
1. Introduction ..................................................................................................................................................................................5
1.1 Restriction of Hazardous Substances Directive (RoHS) ...................................................................................................................................................... 5
1.2 Revision history ......................................................................................................................................................................................................................... 5
1.3 Service manual contents .......................................................................................................................................................................................................... 5
1.4 Service bulletins ........................................................................................................................................................................................................................ 5
1.5 Serial Numbers .......................................................................................................................................................................................................................... 6
1.6 Required equipment for service ............................................................................................................................................................................................. 6
2. Product specification and images ................................................................................................................................................7
3. Firmware & software ....................................................................................................................................................................8
3.1 Firmware revision history ....................................................................................................................................................................................................... 8
3.2 Firmware update instructions ................................................................................................................................................................................................. 8
3.3 Test Mode application .............................................................................................................................................................................................................. 9
4. Operational description ............................................................................................................................................................. 11
4.1 Series description ..................................................................................................................................................................................................................... 11
4.2 Model descriptions ..................................................................................................................................................................................................................11
4.3 Amplifier module .....................................................................................................................................................................................................................12
5. Loudspeaker disassembly & repair instructions ....................................................................................................................... 17
5.1 Amplifier module .....................................................................................................................................................................................................................17
5.2 Front grille ................................................................................................................................................................................................................................19
5.3 Front baffle ...............................................................................................................................................................................................................................19
5.4 High frequency transducer.................................................................................................................................................................................................... 20
5.5 Low frequency transducer .....................................................................................................................................................................................................21
5.6 Handles, feet, and pole mount ..............................................................................................................................................................................................21
6. Amplifier module disassembly & repair instructions ...............................................................................................................23
6.1 Back cover ................................................................................................................................................................................................................................ 23
6.2 AMP/PSU board ...................................................................................................................................................................................................................... 24
6.3 Input/DSP board ..................................................................................................................................................................................................................... 27
6.4 LCD board ................................................................................................................................................................................................................................ 28
6.5 EMI shield and AC line filter board ...................................................................................................................................................................................... 28
6.6 Fan ............................................................................................................................................................................................................................................ 30
6.7 Amplifier module reference ...................................................................................................................................................................................................31
7. Testing .........................................................................................................................................................................................32
7.1 Requirements ........................................................................................................................................................................................................................... 32
7.2 Amplifier module testing ........................................................................................................................................................................................................ 33
7.3 Loudspeaker testing ................................................................................................................................................................................................................ 36
8. Troubleshooting tips...................................................................................................................................................................38
8.1 General tips .............................................................................................................................................................................................................................. 38
8.2 Testing the AC mains fuse and line filter components ...................................................................................................................................................... 39
8.3 Bypassing the AC line filter ................................................................................................................................................................................................... 40
8.4 Power supply MOSFETs and repair .......................................................................................................................................................................................41
8.5 Amplifier MOSFETs ................................................................................................................................................................................................................. 42
8.6 LF and HF amplifier LEDs ...................................................................................................................................................................................................... 43
8.7 +12VLOW voltage rail failures ............................................................................................................................................................................................... 43
8.8 Testing the input/DSP and LCD boards ............................................................................................................................................................................... 44
8.9 LCD ribbon............................................................................................................................................................................................................................... 45
8.10 Input section failure .............................................................................................................................................................................................................. 46
8.11 Fan issues and overheating ................................................................................................................................................................................................. 46
8.12 Front LED ................................................................................................................................................................................................................................ 47
8.13 Internal wiring harness......................................................................................................................................................................................................... 47
8.14 Transducer issues .................................................................................................................................................................................................................. 48
9. Schematics, exploded-view drawings, and BOM ......................................................................................................................49

QSC K.2 series Specifications

General

Brand	QSC
Model	K.2 series
Category	Speakers
Language	English