DSP PWR-DSP3 Uživatelský manuál Strana 1

2005 Pioneer Home Audio SeminarVSX49TXPioneer Electronic Service, Inc. 2005

Use caution when removing screws. There are 3 different types !

Keep track of the screw types.Correct place for screw with integral flat and attachedstar washer.

With the screws removed, gently pull back on the back panel, while extracting the DSP and DSP3 assemblies.

DSP boards removed

Digital Signal ProcessingThe DSP circuit consists of 3 boards1. AWK7719 DSP ASSY2. AWK7727 DSP3 ASSY3. AWK7725 DAC10 ASSY

DSP assembliesDAC10 ASSY#3DSP3 ASSY #2DSP ASSY#1

DSP ASSY

DSP3 ASSY

DAC10 ASSY

SetupDVD Digital Input either Coaxial or OpticalSpeaker setup 5.1 or 5 channel(without Subwoofer)Must use DVD with Surround information{Be sure to loo

For your reference onlyDepending on the accuracy of your scope, this voltage, 5 volts (TTL level), may vary by + or - .5 volts.

DSP Audio Block Diagram

DSP Audio Circuit

DSP Audio Circuit…continued

DSP Audio Circuit…continued

DSP Audio Circuit…continued

DSP Audio Circuit…continued

DSP Audio Circuit…continued

Test point DIR & DIT Pin 3 IC112 DIR & DITPin 3 In

Test point DIR&DIT IC101 Pin 3More noise than signalIC101Pin 3 DIR & DIT In

IntroductionWhy the VSX49TX?The VSX49TX is not current product, however it tends to be the most difficult to repair!What will be covered?The receiver

Test point DIR&DIT Pin 25IC101Pin 25 DIR&DIT Out

Test point DIR&DIT Pin 25IC101Pin 25 DIR&DIT Out

Test point Selector IC112 Pin 3IC 112Pin 3 Selector In

Test point IC112 Pin 3IC112Pin 3 Selector In

Test point Selector IC112 Pin 4IC112Pin 4 Out

Test point Selector IC112 Pin 4Test PointPin 4 Out

Test point DSP1 IC301 Pin 6IC301DSP1Pin 6 In

Test point DSP1 IC301 Pin 6Waveform very small. More noise than signal!

Test point DSP1 IC301 Pin 12IC301DSP1Pin 12 Out

Test point DSP1 IC301 Pin 12

This seminar manual will be specifically about troubleshooting techniques, no operation instructions, no theory!

Test point DSP2 IC401 Pin 11IC401DSP2Pin 11 In

Question…How do I troubleshoot the DSP2 IC? It’s located directly under the DSP3 ASSY.Answer..Simply remove the DSP3 ASSY.There won’t be any sound out

Test point DSP2 IC401Pin 11 In

DSP2 IC401 Pin 5 OutIC401DSP2Pin 5 Out

DSP2 IC401 Pin 5 Out

DSP3 IC501 Pin 6 InIC501DSP3Pin 6 In

DSP3 IC501 Pin 6 In

DSP3 IC501 Pin 12 OutIC501DSP3Pin 12 Out

DSP3 IC501 Pin 12 Out

DAC10 CN6002 Pin 11 InDAC10 ASSYCN6002 Pin 11 In

What will you get out of this?You will learn the most successful troubleshooting methods designed to get the unit on and off your bench as quickly as

DAC10 CN6004 Pin 10 OutDAC10 ASSYCN6004 Pin 10 Out

DAC10 CN6004 Pin 10 OutEnd of the line! Analog audio!Success!

Conclusion to DSP troubleshooting1. Follow the digital signal into and out of DSP1, DSP2 and DSP3 ICs. Compare to waveforms seen in this presentation

DSP Audio Flow PathIdeal path to follow(Left Surround)JA107(DSP ASSY) IC101(DSP ASSY) IC112(DSP ASY) IC301(DSP1)(DSP ASSY) IC410(Selector)

Continued DSP PathCN6002(DAC10) IC6061(DAC10) IC6303(DAC10) IC6305(DAC10) CN6004(DAC10) CN5813(MotherASSY) CN5818(Mother ASSY) CN50

DSP Socket IssuesIC304 on DSP ASSY and IC504 on DSP3 ASSY.Cold solder connections on these sockets can cause loss of audio in DSP mode. For complete l

DSP troubleshooting tipsComplete loss of audioStep 1. Use Multi-Channel input jacks at rear.Step 2. Switch unit to Multi-Channel.Step 3. If audio retu

Easy tips for troubleshooting audioLoss of Analog audioInsert audio(Signal Injector), or noise(put finger on Test Point to generate noise), to ensure

Amplifier and Protection Circuit

Protection Circuit

Topics we will coverMinor disassemblyDSP circuitryAmplifier & Protection circuitsSystem MicroprocessorDisplay MicroprocessorPower SupplyAdditional

ProblemUnit shuts off…Display reads “AMP ERROR”Probable cause…Damaged amplifier components.

Can there be other causes?YES!How do I know if the amplifier is damaged for certain?

How to check for DC OffsetDC Detection, Pin 15. Should be low(0V + - .5V)in normal operation. A high(5V + - .5V) denotes DC Offset and probable Amplif

What if DC Offset is detected?How do I know which of the 7.1 channel(s) is bad?

Test points to narrow choices for DC OffsetPlease note: DC Offset at these Test points can only be measured whenthe Power Supply voltages are up to sp

What if the voltage is within spec?Check these transistors for all channels. Possibly shorted!

None of those other parts bad?Last place to look!

Amplifier

Amplifier FailuresBad Voltage Amp IC.If after replacing damagedIC(s), the amplifier(s) still shows DC Offset, one or both of these resistor(s) may be

Amplifier Failures1. Amplifier outputNumber 1 causeAlways replace in pairs.Don’t assume this is the only damage!

DisassemblyRemove no more than you have to!Use caution when removing the back panel screws. They are different !You are using your ESD wrist strap

Amplifier FailuresIf amplifier continues to have DC Offset after replacing output F.E.T.s, be sure to check these .1 Ohm resisters2. Amplifier output

System Microprocessor Basics

Standby Voltage On/OffRYCTRL= Relay ControlDon’t become confused! This output line controls the operation of the standby 5.6 V line, not the ACrelays.

Energizing AC RelaysIf no DC Offset is present, Pins 58 and 60 will change state to control Port Expander IC.PIN 60 EXPOE2Change of state enables Expa

Turn on signal for AC relays from MicroRAC1 & RAC2To turn on AC RelaysTip…Look for change of stateData and control lines

Mute…Main and Multi-RoomPin 67 changes state to mute audio lines supplying MULTI-ROOMOutputs.Pin 66 changes state to mute all audio lines to MAIN ampl

Display MicroprocessorBasics

Turn on procedureKey Scanin lines.Most importantfor Turn On, Key Scan 1.Look for lowwhen pressingthe Stand By button. This point, whenstatically measu

Communication between MicrosWake-Up output signal from IC3001, Pin 7, to input IC 5801,pin 20.

Volume up and downVolume upLook for change of state from high to low when turning volume up.Tip: Erratic voltage at Test point?Change Volume Encoder.

To start…1. Place unit as pictured and remove top, bottom and side covers.2. Prop up unit as pictured for easy access.3. Remove all screws holding the

Volume downLook for change of statefrom high to low when turningvolume down.Tip: Erratic voltage at Test point?Change Volume Encoder.

Changing inputsLook for change of state fromhigh to low when turning the inputknob to the left.Tip: Changing inputs by itself?1. Look into bulletin SI

Changing inputsLook for change of state fromhigh to low when turning the input knob to the right.Tip: Changing inputs by itself?1. Look at bulletin SI

Things to keep in mindFirst and foremost, don’t overlook the obvious!This is a very complex receiver. There are 16 fuses, A.K.A. IC Protectors,11 regu

To aid in TroubleshootingFirst be sure the unit is not drawing more than 1.65 amps at 120 volts! Placing a shortacross C1002 will allow the unit to be

Normal ConditionUnit at idle, no input, no load(Note: 2.5 amp scale)1.65 amp + or – 10%

Note to current draw…Normal current draw aftersettling, 1.65 amps.Note: The unit will draw in excess of 7.5 amps as you run upthe AC voltage. Look for

Be sure to check all regulated supplies

Power supply voltagesCN40041. +5 volts Digital2. -5 volts Digital3. +5.6 volts 4. -5.6 volts5. +5.6 volts6. +15 volts Tuner7. +20 volts

Power supply voltagesJ40011. +52. Ground

Remove only the screws necessary as shown below.Why spend more time than you have to?

Power supply voltagesJ40041. +27 volts2. Ground3. -27 volts4. +55 volts5. Ground6. -55 volts

Power supply voltagesVery important!Stand by 5.6 volts for the microprocessor

Please check on our Web Site for all Tips and Bulletins when repairing any product.

One brief note on ESDLocated on our PioneerElectronics.comwebsite under training…5S ESD TrainingThe importance of ESD safe practice and preparation is

Additional resources for ESD information…1. ESDsystems.com2. Desco.com

We sincerely hope you will benefit from this information.Thank you