IMPORTANT SAFETY NOTICE Proper service and repair is important to the safe, reliable operation of all Philips Consumer Electronics Company** Equipment. The service procedures recommended by Philips and described in this service manual are effective methods of performing service operations. Some of these service operations require the use of tools specially designed for the purpose.
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FIRE AND SHOCK HAZARD 1. Be sure all components are positioned in such a way as to avoid the possibility of adjacent component shorts. This is especially important on those chassis which are transported to and from the service shop. 2.
LEAKAGE CURRENT COLD CHECK 1. Unplug the ac line cord and connect a jumper between the two prongs of the plug. 2. Turn on the power switch. 3. Measure the resistance value between the jumpered ac plug and all exposed cabinet parts of the receiver, such as screw heads, antennas, and control shafts.
TV SAFETY NOTES SAFETY CHECKS After the original service problem has been corrected, a complete safety check should be made. Be sure to check over the entire set, not just the areas where you have worked. Some previous servicer may have left an unsafe condition, which could be unknowingly passed on to your customer.
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The use of a substitute part which does not have the same safety characteristics as the Philips recommended replacement part shown in this service manual may create shock, fire, or other hazards.
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PREVENTION OF ELECTROSTATIC DISCHARGE (ESD) Some semiconductor solid state devices can be damaged easily by static electricity. Such components commonly are called Electrostatically Sensitive (ES) Devices, Examples of typical ES devices are integrated circuits and some field-effect transistors and semiconductor "chip" components. The following techniques should be used to help reduce the incidence of component damage caused by electrostatic discharge (ESD).
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PRACTICAL SERVICE PRECAUTIONS IT MAKES SENSE TO AVOID EXPOSURE TO ELECTRICAL SHOCK. While some sources are expected to have a possible dangerous impact, others of quite high potential are of limited current and are sometimes held in less regard. ALWAYS RESPECT VOLTAGES. While some may not be dangerous in themselves, they can cause unexpected reactions –...
Technical Specifications, Connections and Chassis Overview Technical Specifications Audio ratings 1 W mono 2 x 1 W non-DBX stereo (LC stereo) 2 x 3 W DBX stereo (with SAP) Reception Tuning system : PLL Color systems : NTSC Sound systems : FM-mono : BTSC non-DBX BTSC DBX...
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Connections Front Or Top Control, Front Or Side Connections Audio / Video In 1 - Video 1 Vpp / 75 Ω 2 - Audio L (0.2 Vrms / 10 kΩ) 3 - Audio R (0.2 Vrms / 10 kΩ) 4 - Headphone (3.5 mm) 8 - 600 Ω/ 4 mW Rear Connections...
Abbreviation list 2 Carrier (or Channel) Stereo Automatic Channel Installation: algorithm that installs TV sets directly from cable network by means of a predefined TXT page Analogue to Digital Converter Automatic Frequency Control: control signal used to tune to the correct frequency Automatic Fine Tuning Automatic Gain Control: algorithm that controls the video input of the featurebox Amplitude Modulation...
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East West, related to horizontal deflection of the set External (source), entering the set via SCART or Cinch Fast Blanking: DC signal accompanying RGB signals FILAMENT Filament of CRT FLASH Flash memory Field Memory Frequency Modulation Horizontal Acquisition: horizontal sync pulse coming out of the HIP Horizontal Flyback Pulse: horizontal sync pulse from large signal deflection Headphone Colour phase control for NTSC (not the same as 'Tint')
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Phase Locked Loop. Used for e.g. FST tuning systems. The customer can give directly the desired frequency Power-On Reset Progressive Scan Scan mode where all scan lines are displayed in one frame at the same time, creating a double vertical resolution. Picture Tube Panel (or CRT-panel) Random Access Memory Remote Control handset...
Service Modes, Error Codes And Fault Finding Test Points The chassis is equipped with test points printed on the circuit board assemblies. These test points refer to the functional blocks: The numbering is in a logical sequence for diagnostics. Always start diagnosing within a functional block in the sequence of the relevant test points for that block. Perform measurements under the following conditions: •...
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Service Default Mode (SDM) Purpose • To create a predefined setting to get the same measurement results as given in this manual. • To override SW protections. • To start the blinking LED procedure. Specifications • Tuning frequency: 61.25 MHz (channel 3). •...
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How to enter SDM • Use a standard customer RC-transmitter and key in the code 062596 directly followed by the MENU button, or • Short wires 9631 and 9641 on the mono carrier and switch the set ON apply AC power. Then press the power button (remove short after start-up).
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How to navigate • When you press the MENU button on the remote control, the set will switch between the SDM and the normal user menu (with the SDM mode still active in the background). Return to the SDM screen with the OSD / STATUS button. •...
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How to enter • Use a standard customer RC-transmitter and key in the code 062596 directly followed by the OSD / STATUS button or • Via ComPair. The following screen is visible, with SAM at the upper right side for recognition. 1.
How to navigate • In SAM, select menu items with the CURSOR UP/DOWN key on the remote control transmitter. The selected item will be highlighted. When not all menu items fit on the screen, move the CURSOR UP/DOWN key to display the next / previous menu items. •...
5. Indicates if the set is not receiving an 'IDENT' signal on the selected source. It will display 'Not Tuned'. 6. Indicates if the sleep timer is enabled. 7. Indicates if the V-chip feature is enabled. 8. Value indicates parameter levels at CSM entry. CO = CONTRAST, CL = COLOR, BR = BRIGHTNESS, HU = HUE, SH = SHARPNESS 9.
Picture too dark or too bright Increase / decrease the BRIGHTNESS and / or the CONTRAST value when: • The picture improves after you have pressed the 'Smart Picture' button on the remote control. • The picture improves after you have switched on the Customer Service Mode The new 'Personal' preference value is automatically stored.
ComPair Introduction ComPair (Computer Aided Repair) is a service tool for Philips Consumer Electronics products. ComPair is a further development on the European DST (service remote control), which allows faster and more accurate diagnostics. Compare has three big advantages: • ComPair helps you to quickly get an understanding on how to repair the chassis in a short time by guiding you systematically through the repair procedures.
• If both ComPair and SearchMan (Electronic Service Manual) are installed, all the schematics and the PWBs of the set are available by clicking on the appropriate hyperlink. Example: Measure the DC-voltage on capacitor C2568 (Schematic/Panel) at the Monocarrier. Click on the 'Panel' hyperlink to automatically show the PWB with a highlighted capacitor C2568. Click on the 'Schematic' hyperlink to automatically show the position of the highlighted capacitor.
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Error Codes Introduction The error code buffer contains all errors detected since the last time the buffer was erased. The buffer is written from left to right. When an error occurs that is not yet in the error code buffer, it is written at the left side and all other errors shift one position to the right.
The Blinking LED Procedure Via this procedure you can make the contents of the error buffer visible via the front LED. This is especially useful when there is no picture. When the SDM is entered, the LED will blink the contents of the error-buffer. Error-codes ≥...
Protections If a fault situation is detected an error code will be generated and if necessary the set will be put in the protection mode. Blinking of the red LED at a frequency of 3 Hz indicates the protection mode. In some error cases the microprocessor does not put the set in the protection mode.
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Alignments Note: The Service Default Mode (SDM) and Service Alignment Mode (SAM) are described in chapter 5. Menu navigation is done with the 'CURSOR UP, DOWN, LEFT or RIGHT' keys of the remote control transmitter. General Alignment Conditions Perform all electrical adjustments under the following conditions: •...
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Hardware Alignments Fig. 1 Vg2 Adjustment 1. Activate the SAM. 2. Go to the WHITE TONE sub menu. 3. Set the values of NORMAL RED, GREEN and BLUE to 40. 4. Go, via the MENU key, to the normal user menu and set - CONTRAST to zero.
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5. Return to the SAM via the MENU key. 6. Connect the RF output of a pattern generator to the antenna input. Test pattern is a 'black' picture (blank screen on CRT without any OSD info). 7. Set the channel of the oscilloscope to 50 V/div and the time base to 0.2 ms (external triggering on the vertical pulse). 8.
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Software Alignments And Settings Enter the Service Alignment Mode (see Service Modes, Error Codes and Faultfinding). The SAM menu will now appear on the screen. Select one of the following alignments: Options Option Byte Chart MS2530C121 MS2530C125 MS2730C121 MS3250C121 MS3250C129 MS3650C129 MT2501C121 MT2501C125...
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Options are used to control the presence / absence of certain features and hardware. How to change an Option Byte An Option Byte represents a number of different options. Changing these bytes directly makes it possible to set all options very fast. All options are controlled via seven option bytes. Select the option byte (OB1..
• OP25: CHANNEL_NAMING 0 : Name FM Channel is disabled or not applicable, 1 : Name FM Channel is enabled, Default setting : 0. Note : Name FM channel can be enabled only when FM_RADIO = 1. • OP26: SMART_PICTURE 0 : Smart Picture is disabled or not applicable, 1 : Smart Picture is enabled, Default setting : 1...
• OP37: EW_FUNCTION 0 : EW function is disabled. In this case, only Expand 4:3 is allowed, Compress 16:9 is not applicable. 1 : EW function is enabled. In this case, both Expand 4:3 and Compress 16:9 are applicable. Default setting : 0. •...
• OP52: SVHS 0 : SVHS source is not available, 1 : SVHS source is available, Default setting : 0. Note : This option bit is not applicable for EU. • OP53: CVI 0 : CVI source is not available, 1 : CVI source is available, Default setting : 0.
• OP65: SMART_CLOCK 0 : Smart Clock Using Teletext and Smart Clock Using PBS is disabled or not applicable, 1 : Smart Clock Using Teletext and Smart Clock Using PBS is enabled. For NAFTA, menu item AUTOCHRON is present in the INSTALL submenu, Default setting : 0.
• OP74: Reserved Default setting : 0. • OP75: Reserved Default setting : 0. • OP77 and 76: TIME_WIN1, TIME_WIN2 00 :The time window is set to 1.2s 01 : The time window is set to 2s 10 : The time window is set to 5s 11 : not in use Default setting : 01 Note :The time-out for all digit entries depend on this setting.
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Read only bit, for monitoring purpose only. Read only bit, for monitoring purpose only. White Tone In the WHITE TONE sub menu, the values of the black cut off level can be adjusted. Normally, no alignment is needed for the WHITE TONE. You can use the given default values. The color temperature mode (NORMAL, COOL and WARM) and the color (R, G, and B) can be selected with the UP/DOWN RIGHT/LEFT cursor keys.
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Geometry The geometry alignments menu contains several items to align the set, in order to obtain a correct picture geometry. Connect an external video pattern generator to the aerial input of the TV-set and input a crosshatch test pattern. Set the generator amplitude to at least 1 mV and set frequency to 61.25 MHz (channel 3).
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Vertical: • Vertical slope (VSL) Align the vertical center of the picture to the vertical center of the CRT. This is the first of the vertical alignments to perform. For an easy alignment, set SBL to ON. • Vertical Amplitude (VAM) Align the vertical amplitude so that the complete test pattern is visible. •...
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Audio No alignments are needed for the audio sub menu. Use the given default values. Default value is 8. OFF for mono sets, ON for stereo sets. Default value is 42. OFF for mono sets, ON for stereo sets.
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Test point overview Main Panel Test point overview CRT Panel...
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I2C and Supply Voltage Diagram Note: For a good understanding of the following circuit descriptions, please use the block diagram or the electrical diagrams. Where necessary, you will find a separate drawing for clarification.
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Introduction The L8/M8 chassis is a global TV chassis for the model year 2001 and is used for TV sets with screen sizes from 25" - 36" (large screen), in Super Flat, Real Flat and Wide Screen executions. The standard architecture consists of a Main panel, a Picture Tube panel, a Side I/O panel and a Top Control panel. In some executions, a Picture In Picture (PIP) panel is used.
The L8/M8 is divided into 2 basic systems, i.e. mono and stereo sound. While the audio processing for the mono sound is done in the audio block of the UOC, an external audio processing IC is used for stereo sets. The tuning system features 181 channels with on-screen display.
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Audio signal processing Mono In mono sets, the signal goes via the SAW filter (position 1002), to the audio demodulator part of the UOC IC 7200. The audio output on pin 48 goes, via the smart sound circuit (7941 for Bass and 7942 for Treble) and buffer 7943, to the audio amplifier (AN7523 at position 7902).
Mono set Video Signal Processing The processing circuits listed above are all integrated in the UOC TV processor. The surrounding components are for the adaptation of the selected application. The I 2 C bus is for defining and controlling the signals. RF signal processing The incoming RF signal goes to the tuner (pos.
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Video source selection The Composite Video Blanking Signal (CVBS) from buffer 7201 goes to the audio carrier trap filters (1200, 1201, or 1202 depending on the system used) to remove the audio signal. The signal then goes to pin 40 of IC 7200. The internal input switch selects the following input signals: •...
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Video demodulation The color decoder circuit detects whether the signal is a PAL, NTSC or SECAM signal. The result is made known to the auto system manager. The PAL/NTSC decoder has an internal clock generator, which is stabilized to the required frequency by using the 12 MHz clock signal from the reference oscillator of the microcontroller / teletext decoder.
RGB control The RGB control circuit enables the picture parameters contrast, brightness and saturation to be adjusted, by using a combination of the user menus and the remote control. Additionally automatic gain control for the RGB signals via cut-off stabilization is achieved in this functional block to obtain an accurate biasing of the picture tube.
Deflection Horizontal drive The horizontal drive signal is obtained from an internal VCO, which is running at twice the line frequency. This frequency is divided by two, to lock the first control loop to the incoming signal. When the IC is switched 'on', the 'Hdrive' signal is suppressed until the frequency is correct. The 'Hdrive' signal is available at pin 30.
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These 'V_DRIVE+' and 'V_DRIVE-' signals are applied to the input pins 1 and 2 of IC 7471 (full bridge vertical deflection amplifier). These are voltage driven differential inputs. As the driver device (IC 7200) delivers output currents, R3474 and R3475 convert them to voltage. The differential input voltage is compared with the voltage across measuring resistor R3471 that provides internal feedback information.
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East/West correction In the M8, there are three types of CRTs, namely the 100º, 110º and wide screen CRTs. The 100º CRT is raster-correction- free and does not need East/West correction. The 110º4:3 CRT comes with East/West correction and East/West protection. The wide screen TV sets have all the correction of the 110 4:3 CRT and also have additional picture format like the 4:3 format, 16:9, 14:9, 16:9 zoom, subtitle zoom and the Super- Wide picture format A line, written at the upper- or lower side of the screen, will be larger at the screen center when a fixed deflection current is used.
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Figure 2 Introduction The supply is a Switching Mode Power Supply (SMPS). The frequency of operation varies with the circuit load. This 'Quasi- Resonant Flyback' behavior has some important benefits compared to a 'hard switching' fixed frequency Flyback converter. The efficiency can be improved up to 90%, which results in lower power consumption. Moreover the supply runs cooler and safety is enhanced.
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Derived Voltages The voltages supplied by the secondary windings of T5520 are: • 'MainAux' for the audio circuit (voltage depends on set execution, see table below), • 3.3 V and 3.9 V for the microprocessor and • 'MainSupply' for the horizontal output (voltage depends on set execution, see table below). Other supply voltages are provided by the LOT.
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Degaussing When the set is switched on, the degaussing relay 1515 is immediately activated as transistor 7580 is conducting. Due to the RC-time of R3580 and C2580, it will last about 3 to 4 seconds before transistor 7580 is switched off. Basic IC Functionality For a clear understanding of the Quasi-Resonant behavior, it is possible to explain it by a simplified circuit diagram (see Figure below).
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In the Quasi-Resonant mode each period can be divided into four different time intervals, in chronological order: • Interval 1: t0 < t < t1 primary stroke At the beginning of the first interval, the MOSFET is switched 'on' and energy is stored in the primary inductance (magnetization).
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The 'soft start' switch is closed when the VCC reaches a level of 7 V and the 'soft start' capacitor CSS (C2522, between pin 5 and the sense resistor R3526), is charged to 0.5 V. Once the VCC capacitor is charged to the start-up voltage VCC-start (11 V), the IC starts driving the MOSFET. Both internal current sources are switched 'off' after reaching this start-up voltage.
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Operation The supply can run in three different modes depending on the output power: • Quasi-Resonant mode (QR) The QR mode, described above, is used during normal operation. This will give a high efficiency. • Frequency Reduction mode (FR) The FR mode (also called VCO mode) is implemented to decrease the switching losses at low output loads.
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Standby The set goes to Standby in the following cases: • After pressing the 'standby' key on the remote control. • When the set is in protection mode. In Standby, the power supply works in 'burst mode'. Burst mode can be used to reduce the power consumption below 1 W at stand-by.
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For a more detailed description of one burst cycle, three time intervals are defined: • t1: Discharge of VCC when gate drive is active During the first interval, energy is transferred, which result in a ramp- up of the output voltage (VSTAB) in front of the stabilizer. When enough energy is stored in the capacitor, the IC will be switched 'off' by a current pulse generated at the secondary side.
Over Voltage Protection The Over Voltage Protection ensures that the output voltage will remain below an adjustable level. This works by sensing the auxiliary voltage via the current flowing into pin 4 (DEM) during the secondary stroke. This voltage is a well-defined replica of the output voltage.
Over Temperature protection When the junction temperature exceeds the thermal shutdown temperature (typ. 140º C), the IC will disable the driver. When the VCC voltage drops to UVLO, the VCC capacitor will be recharged to the V(start) level. If the temperature is still too high, the VCC voltage will drop again to the UVLO level (Safe-Restart mode).
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In- And Output Selection For the control of the input and output selections, there are three lines: • STATUS1 This signal provides information to the microprocessor on whether a video signal is available on the SCART1 AV input and output port (only for Europe). This signal is not connected in NAFTA sets. •...
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− In case of a high voltage appearing across capacitor 2401 (dependent of the tube size), which is high enough to trigger zener diode 6401 into conduction, transistor Q7606 (in A7 diagram) will conduct and UOC is triggered to shut down the power supply.
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SCHEMATIC BLOCK BY BLOCK CIRCUIT DESCRIPTION...
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S = Safety Part Be sure to use exact replacement part. CH0127C121 - Manual no. 7603 Main Chassis Main Chassis 0137 Spring For Item 7400 ..3139 121 24581 0140 Spring For Item 7460 ..3139 121 24581 Front I/O, Control, Headphone Panel Front I/O, Control, Headphone Panel PIP Panel...
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PA0127C121 - Manual no. 7603 2220 0.47uF., 10%, 50 Volt, Polyester . . . 3198 014 04740 Main Chassis Main Chassis 2221 0.022uF., 50 Volt, Ceramic..3198 017 02230 2241 1500pF., 50 Volt, Ceramic..3198 017 01520 0137 Spring For Item 7400 .
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S = Safety Part Be sure to use exact replacement part. PC0127C121 - Manual no. 7603 Main Chassis Main Chassis 0137 Spring For Item 7400 ..3139 121 24581 0140 Spring For Item 7460 ..3139 121 24581 Front I/O, Control, Headphone Panel Front I/O, Control, Headphone Panel PIP Panel...
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S = Safety Part Be sure to use exact replacement part. PCW127C121 - Manual no. 7603 Main Chassis Main Chassis 0137 Spring For Item 7400 ..3139 121 24581 0140 Spring For Item 7460 ..3139 121 24581 Front I/O, Control, Headphone Panel Front I/O, Control, Headphone Panel PIP Panel...
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S = Safety Part Be sure to use exact replacement part. PL0125C125 - Manual no. 7603 Main Chassis Main Chassis 0137 Spring For Item 7400 ..3139 121 24581 0140 Spring For Item 7460 ..3139 121 24581 Front I/O, Control, Headphone Panel Front I/O, Control, Headphone Panel PIP Panel...
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S = Safety Part Be sure to use exact replacement part. PL0127C121 - Manual no. 7603 Main Chassis Main Chassis 0137 Spring For Item 7400 ..3139 121 24581 0140 Spring For Item 7460 ..3139 121 24581 Front I/O, Control, Headphone Panel Front I/O, Control, Headphone Panel PIP Panel...
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S = Safety Part Be sure to use exact replacement part. PPC132C121 - Manual no. 7603 Main Chassis Main Chassis 0137 Spring For Item 7400 ..3139 121 24581 0140 Spring For Item 7460 ..3139 121 24581 7400 Power FET, STP3NC60FP-clip 0137.
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S = Safety Part Be sure to use exact replacement part. PPC136C1 - Manual no. 7603 Main Chassis Main Chassis 0137 Spring For Item 7400 ..3139 121 24581 0140 Spring For Item 7460 ..3139 121 24581 7400 Power FET, STP3NC60FP-clip 0137.
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S = Safety Part Be sure to use exact replacement part. SC3127N121 - Manual no. 7603 Main Chassis Main Chassis 0137 Spring For Item 7400 ..3139 121 24581 0140 Spring For Item 7460 ..3139 121 24581 Front I/O, Control, Headphone Panel Front I/O, Control, Headphone Panel PIP Panel...
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S = Safety Part Be sure to use exact replacement part. SC3132N121 - Manual no. 7603 Main Chassis Main Chassis 0137 Spring For Item 7400 ..3139 121 24581 0140 Spring For Item 7460 ..3139 121 24581 7400 Power FET, STP3NC60FP-clip 0137.
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