QSC K8, Service Manual

Page 1: ...Product Model K8 K10 K12 KSub Document TD 000487 00 Initial Release February 2015 Revised Release Revision A Service Manual QSC Audio Products LLC Costa Mesa California USA www qsc com K Series...

Page 2: ...2 QSC Audio Products LLC...

Page 3: ...nsducers 20 6 3 Handles threaded pole mount and casters 21 7 BOP disassembly and repair procedures 23 7 1 Faceplate 23 7 2 PSU amplifier board 24 7 3 Input DSP board 25 7 4 Power inlet power switch an...

Page 4: ...site www qscservice com Technical Service Group web site www qscparts com parts and accessories sales 13 Exploded view drawings 52 13 1 K8 exploded view 52 13 2 K10 exploded view 53 13 3 K12 exploded...

Page 5: ...only the appropriate ones If you contami nate a tip or braid even inadvertently by using it on a non compliant product or solder you should no longer use it with RoHS compliant products or solder 1 2...

Page 6: ...tor 8ohm resistive load capable of 500 W power handling SPL meter Soldering iron K Family test adapter Distortion analyzer Audio Precision recommended Class D output filter for distortion analyzer Too...

Page 7: ...xt Sub Norm DEEP HF Mode Flat Vocal Boost Front LED On Off Limit Power Gain LF Mode Normal DEEP Polarity Normal Reverse Front LED On Off Limit Indicators Power Signal A Signal B Standby Limit Mic Powe...

Page 8: ...r spins until it s absolutely needed F December 16 2011 GABxxxxxx and newer Test mode changes only to shorten burn in times The firmware revision for K Series loudspeakers is printed on a small label...

Page 9: ...must be performed before any programming takes place The installation file for the USB drivers will work on Windows XP Vista 7 32 bit and 64 bit and 8 1 Disconnect the Aardvark if you ve already conn...

Page 10: ...tory where the HEX file you received is located If you received this firmware file from a QSC employ ee make sure that it s the correct one or the speaker will not work after being pro grammed 4 Turn...

Page 11: ...the speaker Attached to the baffle are two transducers the low and high frequency Each model has a different size low frequency transducer the K8 has a 8 K10 has 10 and K12 has a 12 all extending bass...

Page 12: ...he amplifi er comes out of muting to allow all internal voltages to fully settle Power supply The BOP s switch mode power supply is a regulated fixed frequency active clamped flyback It is similar to...

Page 13: ...input sections A and B each with a balanced combination female XLR TRS jack with a pass through male XLR jack On 2 way versions of BOP each input also has unique features Input A has a switch which in...

Page 14: ...ying the DSP output level Connecting a potentiometer between 5V and ground with the wiper on the attenuation pin allows full control of volume Because the attenuation pin is buffered a single pot can...

Page 15: ...on page 52 5 1 Bucket of power Removal 1 Remove the 10 screws along the outer perimeter of the BOP 2 Partially remove the amplifier module out of the main enclosure as seen in Figure 5 1 Note Occasio...

Page 16: ...to the baffle 4 Use a rubber mallet with a large head to gently press in the sides of the grille so that the grille is flush with the enclosure 5 3 Front baffle Removal 1 To access the front baffle t...

Page 17: ...s from the HF transducer s terminals 2 Remove the 4 rubber plugs from the waveguide 3 Remove the 4 screws that secure the HF transducer to the baffle 4 The HF transducer can now be removed from the ba...

Page 18: ...wire terminals Important note This connection must have high retention force Crimp new fastons 0 205 or 5 21 mm female 14 16 AWG insulated straight to the wiring harness if the old ones are weak 3 Gen...

Page 19: ...e entire pole cup assembly if any parts are broken or have failed Individual parts are not available The pole cup assembly is secured to the enclosure with machine screws on the exterior of the enclos...

Page 20: ...net 4 Fasten the 10 screws that secure the BOP to the cabinet beginning with the corner screws 6 2 Low frequency transducers Removal Contrary to the top box models the LF transducer can only be remove...

Page 21: ...into the cutout in the cabinet 5 Fasten the 8 screws that secure the transducer to the baffle in a star pattern Note Be very careful when installing the screws The screwdriver can easily slip and pie...

Page 22: ...le mount out of the cabinet Verify that any new threaded pole mount has gasket Air will leak out of the cabinet if there is no gasket Caster removal and installation notes Because of the normal wear a...

Page 23: ...brown wire and J15 blue wire 7 Separate the faceplate assembly from the main bucket assembly Complete Installation 1 Install the input DSP and PSU amplifier PCBs to their original locations 2 Connect...

Page 24: ...of the PCB 2 Verify that the thermal pads are clean and placed in their appropriate locations on the bottom of the bucket chassis Warning Thermal pads are also used to isolate the body of the MOSFETs...

Page 25: ...ring is required to install a new IEC power inlet Use the removal instructions in 7 1 Faceplate on page 23 to gain access to the power inlet Two screws secure the power inlet to the faceplate Brown is...

Page 26: ...eshooting and testing the output power of the amplifier Please call and ask for QSC part number SG 000576 TS Activating test mode When the BOP is running in test mode it acts like a full range 2 chann...

Page 27: ...couple of times Verify that you don t lose the signal on the oscilloscope Verify that the power is not lost If a rubber mallet is not available lightly bang the am plifier on the work bench 6 Apply a...

Page 28: ...576 TS Without the test adapter it will be very difficult to connect an 8 ohm load to the molex connector Warning Do not perform full power tests with load for more than 10 seconds It may cause intern...

Page 29: ...ts SPL specifications Step 1 System setup Verify that the BOP is in a normal mode not test mode Connect the output of the audio sine wave generator to channel B input and set the gain to the 12 o cloc...

Page 30: ...repeat the measurement Model 100 Hz SPL dB 5 kHz SPL dB K8 105 dB 102 dB K10 105 dB 102 dB K12 106 dB 102 dB KSub 112 dB n a NOTE These figures apply only to on axis measurements If the SPL meter s mi...

Page 31: ...st to determine the SMPS is switching and generating the main auxiliary voltage rails Follow the instruc tions below to test the PSU amplifier PCB 1 Disconnect AC power from the BOP 2 Wait at least 5...

Page 32: ...ying power to the board through capacitor C45 1 Disconnect AC power from the BOP 2 Remove the faceplate assembly by following removal instructions in 7 1 Faceplate on page 23 3 Connect a bench top DC...

Page 33: ...e component in Figure 9 5 and the table below for lead breaks Check all leads on the components for breaks Any of them could potentially break If you find one of the components has a broken lead there...

Page 34: ...op amp The QSC part number for the MC33078 op amp is IC 000048 30 Symptoms Channel A or channel B green signal LED permanently lit without an input connected BOP emitting noise or distortion to the o...

Page 35: ...of the amplifier feedback path can be done by measuring resistance from the switching node Q2 source and Q3 drain for example back to the comparator inverting input it should be about 11 3k You may c...

Page 36: ...Z SEC 100X40AWG LITZ PRI EE42 3C90 LINEUV 1 27V IMBD4148 20 PCNT 1 0UF 1 PCNT 1 13K 1 PCNT 1 10W BAS21 1 10W 10 10 PCNT 25V 20 PCNT 125VAC STW26NM60 500V 1 PCNT 2 21K 11K 1 PCNT 1 8W 82 5K 5 PCNT 1 PC...

Page 37: ...ltage on R78 could turn off the fan completely Always check for thermal grease application on the temperature sensor 9 8 Internal wiring harness Wiring harness problems tend to occur more often in the...

Page 38: ...to access the LED Symptoms Front LED is not working even with setting on the BOP as FRONT LED or LIMIT Failure verification The BOP is outputting a voltage through the black Molex connector but the fr...

Page 39: ...can result in a very distorted sound Always apply gasket around the rim of the low frequency transducer where it will mate to the surface of the enclosure Poke holes in the gasket material over the m...

Page 40: ...ed Please contact QSC for alternative options If replacing the baffle reuse the rectangular gasket that is installed along the edges of the baffle Carefully re align the gasket as it was previously in...

Page 41: ...13 situation in the affected K Series loudspeakers one remedial and one preven tative The remedial solution is for repairing K Series loudspeakers that are inoperative because of an L13 failure while...

Page 42: ...3A LM393A 2 87 10 PCNT 1 10W 1 10W MC33078 MC33078 20 PCNT 1 PCNT 1 PCNT 1 PCNT 14 0K 1 10W 5K 1 10W 1 PCNT 1 10W 10 0K LM393A 1 0M 1 10W 1 PCNT 1 10W YELLOW 10UF SH 003311 00 AR 003311 00 ZIP NONE J1...

Page 43: ...0K 2 21K 2 21K 5 62K 63 4K 1 PCNT 1 10W 1 PCNT 50V 1 00K 1 PCNT 1 10W 1 PCNT 1 10W 50V 10 PCNT 17 8K 16V 20 PCNT 1 0UF 1 10W 1 PCNT 1 10W MC33078 1 PCNT 1 10W 20 PCNT 0 1UF 10 PCNT 25V 10 0K BAT54S MM...

Page 44: ...D4148 50V 10PF 1 13K 1 13K 1 PCNT 1 10W 21 1 8W BAS21 1 10W 1 PCNT 1 10W 1 PCNT 1 10W 10UF 20 PCNT 25V 5 PCNT 1 PCNT 1 10W 10 1 10W 17 8K 0 1UF 10 PCNT 1 10W 1 PCNT 4 53K 1 PCNT 14 0K 1 PCNT 4 53K 2 2...

Page 45: ...K 1 PCNT 0 022UF 1 10W 10 PCNT 500V 0 022UF 774UH SH 003311 00 AR 003311 00 ZIP NONE D33 D34 D43 D40 D27 D25 D28 D31 D32 D29 D24 D23 BR1 Q13 Q14 T1 T1 T3 T3 D35 C115 C118 C148 C128 C137 C125 C129 D38...

Page 46: ...5 FRONT LED 6 AMP SD 7 7V 8 PGND 9 15V 10 15V J5 PINOUTS 1 2 FAN FAN J6 PINOUTS 1 5V 2 VOL 3 GND INPUTS SIGNAL PROCESSING SIG PRE LED INPUT A 2 WAY LINE IN B J10 J11 J12 U14 A SIGNAL PRESENCE LED INPU...

Page 47: ...E Q3 NEGATIVE TEMP TO VOLT SENSOR U9 PIN1 V PIN2 VO PIN3 GND RECTIFIER DIODES D33 POSITIVE D34 NEGATIVE PSU SWITCHING Q14 MAIN SWITCHING FET Q5 ACTIVE CLAMP FET J3 PINOUTS 2 WAY 1 CH2 OUT YEL 2 CH2 OU...

Page 48: ...4 01 For K10 use PA 000245 01 For K12 use PA 000246 01 1 SB 00015x TS FRONT BAFFLE SUBASSY BLK Includes baffle L R ports LED and wiring harness For K8 use SB 000155 TS For K10 use SB 000156 TS For K12...

Page 49: ...oards together Cannot be separated For K8 use WP 003311 00 For K10 use WP 003312 00 For K12 use WP 003313 00 1 WP 00330x 00 CHASSIS ASSY MAIN UNIVERSAL SUPPLY Fully assembled amplifier module replacem...

Page 50: ...00436 00 PLUG EURO 3 POS MALE GRN 1 CO 000386 00 JACK IEC 3 POS FEMALE LOCKING 1 CO 000168 00 XLR COMBO 3 POS FEMALE VERTICAL W LATCH Locking tab version only on later K models CO 000414 00 SOB XLR CO...

Page 51: ...ice Manual Partnumberanddescription Quantity RE 000300 NR NTC 2 5 OHMS 8 AMPS INRUSH LIMIT 90J 1 SW 000088 GP ROCKER POWER SWITCH 1 WP 000367 00 FAN ASSY BOP 2CH 1 XF 000376 00 INDUCTOR COMMON MODE TO...

Page 52: ...000603 01 POLE CUP SELECTOR ANGLE K SERIES BLK 1 27 PL 000604 01 POLE CUP RETAINER SELECTOR K SERIES BLK 1 28 PL 000606 01 FLARE PORT RIGHT K8 BLK 1 29 PL 000619 01 PLUG HORN K8 BLK 4 30 LB 000942 01...

Page 53: ...S BLK 1 27 PL 000604 01 POLE CUP RETAINER SELECTOR K SERIES BLK 1 28 PL 000607 01 FLARE PORT RIGHT K10 BLK 1 29 LB 000942 01 LABEL HOLE COVER 700 DIA 3 30 LB 000942 00 LABEL HOLE COVER 976 DIA BLK 2 3...

Page 54: ...QSC Audio Products LLC 13 3 K12 exploded view WP 003304 01 DRW As Stored from PDMLink via ProductView March 26 2012 11 40AM Drawing Release Level Production User Name Denise Delarm...

Page 55: ...01 POLE CUP SELECTOR ANGLE K SERIES BLK 1 29 PL 000604 01 POLE CUP RETAINER SELECTOR K SERIES BLK 1 30 PL 000608 01 FLARE PORT RIGHT K12 BLK 1 31 LB 000942 01 LABEL HOLE COVER 700 DIA 3 32 LB 000942...

Page 56: ...LED HOLDER FOR HPR 1 13 PL 000638 01 BAFFLE SIDE PORT KSUB not available 2 14 PL 000640 01 HANDLE BACK CUP KSUB 2 15 PL 000659 01 LOGO K12 BLK 1 16 QD 000312 GP LED 3MM BLUE SP SLR343BB T 225419 ROHM...

Page 57: ...ADED INSERT M5 STEEL BLK OXIDE 4 CH 001143 01 THREADED INSERT M10 STEEL BLK OXIDE 2 CH 001153 01 GRILLE W NO LOGO BLK K8 1 0MM 1 Use grille assembly PA 000244 01 LB 000942 00 LABEL HOLE COVER 976 DIA...

Page 58: ...1 14 3 FG 003302 01 120V or FG 003322 01 230V K10 PartNumber Description Qty Reference Comment CO 000436 00 PLUG EURO 3 POS MALE GRN 1 LB 000748 00 LABEL GRILLE TAG K10 1 PM 000270 GP POLYBAG MANUAL...

Page 59: ...K 1 QD 000312 GP LED 3MM BLUE SP SLR343BB T 225419 ROHM 1 SB 000074 01 BUCKET K10 BLK 1 Not available SB 000078 01 BAFFLE K10 BLK 1 Use baffle assembly SB 000156 TS SC 000097 GP SCR PHH PNH M5 35 L ST...

Page 60: ...593 00 STRIP GASKET 5X500 EVA 0 MS 000604 00 GASKET STRIP K SERIES 2 NW 000161 00 NUT HEX FLG SERR M5 STL CLR ZINC CR3 20 NW 000168 00 WSHR RTNR M8 STL CLR ZINC CR3 2 NW 000169 00 WSHR SPLKG M6 STL CL...

Page 61: ...7 THK STL CLR ZINC CR3 4 NW 000140 00 NUT HEX KEPS W TOOTH WSHR M4 STL CLR ZINC 1 NW 000147 00 NUT HEX M3 STL CLR ZINC CR3 4 NW 000173 00 WSHR FLT M3 3 2 ID 8 0 OD 1 0 THK STL BLK ZINC CR3 8 PL 000627...

Page 62: ...20 PCNT 16V CERAMIC Y5V 0805 6 C115 C128 C137 C148 C38 C44 CA 610011 30 10UF 20 PCNT 16V ELECTROLYTIC SMT NON POLAR 5 C54 C79 C80 C97 C98 CA 610021 30 10UF 20 PCNT 25V CERAMIC CAP 1206 19 C103 C110 C1...

Page 63: ...A BAT54S SOT 23 3 D17 D37 D4 QD 000282 30 DIODE RECTIFIER ULTRAFAST 200V 1A ES1D SMA 9 D28 D3 D31 D32 D36 D43 D5 D6 D8 QD 000363 30 DIODE SCHOTTKY 30V 2 0A MBR230 SOD 123 4 D23 D24 D38 D39 QD 000372 0...

Page 64: ...1W METAL OXIDE FP 1 R170 RE 263401 30 63 4K 1 PCNT 1 10W THICK FILM 0805 100V 3 R143 R149 R173 RE 282501 30 82 5K 1 PCNT 1 8W THICK FILM 1206 200V 5 R152 R156 R172 R188 R189 RE 310002 30 100K 1 PCNT...

Page 65: ...604 00 GASKET STRIP K SERIES 1 NW 000171 00 WSHR SPLKG M5 STL CLR ZINC CR3 16 NW 000172 00 WSHR FLT M5 18 OD STL CLR ZINC CR3 16 PL 000062 GP GASKET 1000X10X2MM EVA B 10 PL 000445 GP FEET HPR SUBS RUB...

Page 66: ...L 1 WC 000467 00 WIRE ASSY AC SWITCH 16 AWG 1 CONDUCTOR BOP 2CH 5 00 L BROWN 1 WP 000367 00 FAN ASSY BOP 2CH 1 WP 003314 00 PCB ASSY KSUB UNIVERSAL SUPPLY 1 14 12 WP 003314 00 KSub BOP PCB assembly Pa...

Page 67: ...J11 J9 CO 000422 00 JACK EURO 3 POS MALE VERTICAL BLACK TALL 1 J6 CO 000426 00 WIRE TRAP RIBBON CABLE 10 POS FEMALE RELEASABLE 1 J2B CY 000009 30 12 288MHZ HC49SM 1 Y1 HW 000007 HW FUSE CLIP PC MOUNT...

Page 68: ...8 R169 R182 R183 R196 R197 R198 R199 R200 RE 001006 30 10 1 PCNT 1 10W THICK FILM 0805 100V 3 R125 R165 R72 RE 001960 30 19 6 1 PCNT 1 8W THICK FILM 1206 200V 4 R60 R61 R62 R63 RE 002100 30 21 1 PCNT...

Page 69: ...0 243K 1 PCNT 1 8W THICK FILM 1206 200V 2 R133 R134 RE 410005 30 1 0M 1 PCNT 1 10W THICK FILM 0805 100V 1 R123 SW 000111 00 SWITCH DPDT SLIDE PCB MOUNT 0 805 TERMINALS 2 SW1 SW3 SW 000112 00 SWITCH DP...

Page 70: ...sses or numbers below Telephone 1 800 772 2834 within USA only 1 714 957 7150 Fax 1 714 754 6173 Skype qscaudio E mail tech_support qscaudio com Web sites www qsc com product info support www qscservi...