20GR105073R / PHILIPS [TV]

• Search jumps on UHF.
• Description of SMPS. (with circuit diagram extract)
• Difficult to tune programmes, stations shifted on tuning bar.
• Interference in audio. Interference in picture. (part of circuit diagram displayed) (PHILIPS - 20GR105073R information)
• Slow start up of power supply. (part of circuit diagram displayed)
• Vertical oscillator adjustment procedure. (service info for PHILIPS -20GR105073R)
• Volume change with great fluctuations in brightness. (picture attached)
• Hotel mode.
• Difficultly in tuning to correct position.
• No functions. after start-up (intermittently).
• Change of C2523.
• 95V available. 9V is only 5.2V. Slight buzzing from loudspeakers.
• Green picture after few hours, intermittently fault disappears for short while when switching from a station to another. Strange characters in OSD.
• White unmodulated raster. Picture missing. (part of circuit diagram displayed)
• Set comes on in store lock mode. (with circuit diagram extract) (20GR105073R PHILIPS repair tip)
• Error codes.
• Green screen with flyback lines. Green oscillations. Noise as if HV leaky on picture tube base. (with circuit diagram extract)
• Dark picture.
• Dead. Low frequency noise on sound. (20GR105073R tips)
• Line out of phase. Black band in centre of screen. No colour.
• Correction to service manual LOT winding.
• Only half a picture. (picture attached)
• No picture. TXT OK . (extract of circuit diagram attached)
• Dead. Low hum.
• No colour in OSD.
• Picture shifted to the left. intermittently. Line tearing. intermittently. (extract of circuit diagram attached)
• Green picture. after warm-up. Lines in picture. after warm-up. Does not change channels.
• Sound increases intermittently or "pops", especially during bright scenes. (extract of circuit diagram attached)
• Search jumps on UHF.
• Dead with whistling noise coming from power supply. (part of circuit diagram displayed)
• PAL colour amplitude adjustment procedure.
• Blown chopper. (extract of circuit diagram attached)
• Set won't tune to high frequency channels and lower frequency channels appear to be higher. (extract of circuit diagram attached)
• No function. When switching on with RC, standby LED lights up. (with circuit diagram extract)
• Vertical size varies. intermittently.
• Picture only in two bars in upper screen section, the rest is dark. (+ extract of circuit diagram)
• Memory loss. (with circuit diagram extract)
• Becomes defective immediately after switch on.
• No picture. (picture attached)
• Stuck in hotel mode.
• The TV cannot hold the picture.
• No channel search. No OSD. (part of circuit diagram displayed)
• Change of C2523.
• Protection device (thyristor THY6641) is triggered at switch on. (part of circuit diagram displayed)
• Initial volume level is higher than maximum Hotel mode setting.
• Unregulated power supply. Pulsating picture and surging sound. (picture attached)
• Blank raster. No audio. after a while. (+ extract of circuit diagram)
• Strongly distorted sound by low volume. (service info for PHILIPS -20GR105073R)
• No line output stage. (extract of circuit diagram attached)
• Picture is faint with hanover bars. (with circuit diagram extract)
• Unstable tuning.
• Dim picture with Hanover bars.
• Dead when switched on via mains switch. Though appliance is on, red LED flashes. Can be switched over to standby. If left in standby for 1 hour and then switched on via RC, functions.
• No tuning. (picture attached)
• Field foldover at switch on from cold. Effect disappears when appliance warms up. (part of circuit diagram displayed) (20GR105073R tips)
• Tuning drift, when it is hot the tuning is lost on channel change.
• How to switch off Hotel-Mode:
• Excessive brightness. (20GR105073R tips)
• Horizontal white line. (20GR105073R tips)
• No vertical deflection. (extract of circuit diagram attached)
• Sound goes to max. intermittently and HT varies. (picture attached)
• Adjustment of +95V. (with circuit diagram extract)
• No function. Standby LED flashes briefly. (with circuit diagram extract)
• Tuning drifts. (with circuit diagram extract)
• Buzzing.
• No power with abnormal sound. (picture attached)
• Modification introduced to +9V supply.
• No function at switch on from standby. Switches to LOCK (hotel) mode. (picture attached)
• Delay RF AGC adjustment procedure.
• Comes on for a short time.
• No audio.
• Dead. Only standby-LED works. Responds to TURN ON command, but no image and no sound.
• How to de-activate Hotel mode.
• No start-up. Buzzing from speakers and working noise of PSU. (20GR105073R tips)
• Colours flicker and disappears.
• No frame or short frame. (picture attached)
• Spurious nonsense OSG. Goes to standby after 0.5-2hrs. Loss of tuning.
• Picture passes out in the centre.
• Slight foldover at upper part of picture if appliance is switched on when cold. Fault disappears after few minutes. (+ extract of circuit diagram)
• Line output transistor TR7528 fails at switch on.
• No switch on after activating mains switch. Whistling noise. (+ extract of circuit diagram) (20GR105073R tips)
• Programme tuning difficulty. Stations has shifted on tuning bar.
• Colour flickers. No colour. after a while. (+ extract of circuit diagram)
• How to de-activate Hotel-Mode.
• No audio.
• Appliance can not be programmed. Search does not function. Only limited volume control.
• Stored channels are partially lost.
• +9V supply modification. (part of circuit diagram displayed)
• Only some programs with snowy picture can be tuned and on band 1 missing some programs. (part of circuit diagram displayed) (PHILIPS - 20GR105073R information)
• No sound. No picture. Faint motorboating noise.
• Excessive horizontal size.
• Excessive HV. after a while.
• V-centre adjustment procedure.
• No sound or raster. The 95V HT supply is present at the line output stage but there is no line drive. (+ extract of circuit diagram)
• PSU switches off with load at U95V. (picture attached)
• No +9V, line output stage is OK. (+ extract of circuit diagram)
• Line output transistor running hot. (part of circuit diagram displayed)
• Picture shifts. (picture attached)
• Comes on in standby. When program button pressed standby lamp blinks then goes off.
• Sometimes when turned on, green screen only with flyback lines, at other times no tuning and channel will not change. (part of circuit diagram displayed)
• SOPS defective. (with circuit diagram extract) (20GR105073R tip from PHILIPS)
• Picture shifted to the right. (with circuit diagram extract)
• No regulation. (with circuit diagram extract)
• Initial volume level is higher than maximum hotel mode setting.
• Failures in the power supply. (picture attached)
• Automatic fine tuning (AFT) field alignment procedure. (PHILIPS - 20GR105073R information)
• Settings do not stay in position.
• Dead. (picture attached)
• Intermittent colour. (20GR105073R tips)
• No voltage from PSU. (+ extract of circuit diagram)
• Hums softly. (+ extract of circuit diagram)
• Appliance is dead with standby LED flashing after a few seconds. (part of circuit diagram displayed)
• Microprocessor screening plate. (with circuit diagram extract)
• No audio. (20GR105073R tips)
• 6613 type change. (part of circuit diagram displayed)
• Picture separating line appears. Whistling.
• Programme channel search cannot be called up.
• No HT from chopper circuit. (part of circuit diagram displayed)
• PSU check.
• Identification coil adjustment.
• Line output stage TS7528 is defective. (part of circuit diagram displayed)
• Does not shut down (when cold).
• Line transistor 7528 blows within 1 sec. (picture attached)
• Distorted audio. (service info for PHILIPS -20GR105073R)
• No audio.
• How to enter/exit HOTEL mode.
• Bright picture. Flyback lines.
• Programming unoperational. Limited sound adjustment possible.
• Reduced horizontal size. (picture attached)
• No operation.
• Right hand side of screen has a line.
• No start-up. intermittently.
• No picture. No audio. (picture attached)
• No start up. No standby. Attempts to start up, but fails.
• Dead. At switch on the stand by LED flashes.
• Enable Hotel mode. Disable hotel mode.
• No picture, sound ok but on turning up A1 control, frame collapse. (+ extract of circuit diagram)
• Production change to line drive. (with circuit diagram extract)
• After replacement of the line output transistor BUT12, picture with trapezoid effect, BUT12 overheats and goes defective again. (with circuit diagram extract)
• Loud chriping after switch on. It becomes lower after a short time.
• No tuning. Impossible to change analog control adjustments (brightness, sound, etc.). (picture attached)
• No functions. Sound buzzes in loudspeaker. (part of circuit diagram displayed)
• Buzzing from PSU. when cold. (part of circuit diagram displayed)
• The removal of leaded diodes. (+ extract of circuit diagram) (PHILIPS - 20GR105073R information)
• Green raster. Faint picture. Flyback lines.
• Two lines going around. (picture attached)
• Intermittent green picture, channels cannot be programmed. (with circuit diagram extract) (20GR105073R PHILIPS repair tip)
• Random breakdown of line output transistor. (part of circuit diagram displayed)
• Height excessive. Defective linearity. Field blanking. (with circuit diagram extract)
• No HV.
• No picture (when cold).
• Dead due to action of over voltage protection circuit.
• LED switches on then off immediately.
• No line output.
• Picture centering has shifted horizontally. No OSD.
• Standby LED lights up and switches off at power on. Appliance will not start up.
• Picture is mostly green with flyback lines after 10 secs from switch on.
• The remote control only controls the volume and sound-stop. No function with On-Off and channel change-over, although the display for the operation flickers.
• No functions. Hum in loudspeaker. No LED lit.
• No horizontal synchronisation. (picture attached) (20GR105073R tips)
• When switching on, only a 10cm stripe on top of screen, the rest of screen is black with flyback lines. After a while, stripe becomes wider. (picture attached) (20GR105073R tip from PHILIPS)
• Line output stage does not start up. (+ extract of circuit diagram)
• Store lock on the appliance.
• Memory cannot be opened via "rhombus". Stored channels cannot be changed.
• Set dead with just 5V on the 95V line. Standby LED is on but set won't start. (part of circuit diagram displayed)
• Replacing the EAROM. (part of circuit diagram displayed) (20GR105073R tip from PHILIPS)
• Sound motorboating when cold. (with circuit diagram extract)
• Trips. (+ extract of circuit diagram)
• No tuning - no channels.
• Intermittently dead. after start-up.
• Doesn't tune stations correctly. When cold, crossed lines on low UHF channels. (with circuit diagram extract)
• During picture changes sometimes a volume increase (plop) is heard. (with circuit diagram extract)
• PSU does not start up, if appliance was switched off for a day. Appliance functions after short switch on/off. (extract of circuit diagram attached)
• Won't tune a new channel. Won't activate store function. Picture OK. Sound OK.
• Line output transistor becomes warm and in the course of time it becomes defective. (extract of circuit diagram attached)
• No freeze frame or intermittent freeze frame; no sound. (picture attached)
• Intermittently dead. (picture attached)
• No switch on. Low noise on sound. (with circuit diagram extract)
• Vertical collapse. (picture attached)
• Standby just pulsing.
• Green picture. (20GR105073R tip from PHILIPS)
• Squealing from PSU.
• Bell filter adjustment procedure.
• Does not switch on. LED is lit in standby. If appliance is switched on with RC, LED switches off.
• Intermittent colour and intermittent dark vertical bar on picture.
• Tuning drifts. only on certain channels (after a while).
• Whistling.
• Defective IC7103 SV-production. (extract of circuit diagram attached)
• Streaks in picture. Picture pulls and rolls intermittently.
• No start up from cold and humming.
• No sound. Picture OK. After a short time TV stops. High frequency noise from PSU. (extract of circuit diagram attached)
• Poor synchronisation. when cold. (with circuit diagram extract)
• Buzzing sound then switches off.
• Dead. Low level buzz from loudspeaker. (part of circuit diagram displayed)
• Dead set. Tries to start.
• No tuning possible, F2 appears on bottom of picture and S1 on top.
• No colour.
• Doesn't store stations correctly.
• Poor synchronisation. (with circuit diagram extract)
• Appliance will not switch on at times, but hums in the power supply section.
• Unable to retune set or set analogue levels. Store-lock option may be on "Hotel mode".
• No functions. Slow start-up. (part of circuit diagram displayed)
• Hazy flickering picture at top. (part of circuit diagram displayed)
• Programme tuning difficulty, stations shifted on tuning bar. (picture attached)
• LED flashes once, then gurgles. (extract of circuit diagram attached)
• No functions, hum in loudspeakers. (part of circuit diagram displayed)
• Stops at start up. (+ extract of circuit diagram)
• No colour.
• Stuck in standby. (with circuit diagram extract)
• Horizontal hold adjustment procedure.
• The following production changes were introduced to prevent the set coming on in the store lock mode when switched on from standby. (part of circuit diagram displayed)
• Turns on automatically. No RC or front panel controls.
• The fuse and the bridge diodes in the power supply blow. (20GR105073R tips)
• How to switch off Hotel-Mode.
• Line output transistor fails repeatedly. (extract of circuit diagram attached)
• Enable Hotel mode. (service info for PHILIPS -20GR105073R)
• Defective purity.
• Dark picture. Audio OK .
• Whistle.
• No picture and sound. Low hum intermittently, no function. (20GR105073R tips)
• New infra red receiver.
• No audio.
• Intermittent destruction of line o/p transistor. (extract of circuit diagram attached) (PHILIPS - 20GR105073R information)
• Vertical line. on the right half screen. (with circuit diagram extract)
• SIF DET adjustment procedure.
• Line output stage does not function.
• Vertical vibration in cold condition of set.
• Horizontal oscillator adjustment procedure.
• No start-up. (+ extract of circuit diagram)
• Blank raster. OSD OK .
• Excessive green.
• Dead. Power LED is OFF (ON in standby). Hissing from PSU. (20GR105073R tips)
• Initial volume level is higher than maximum Hotel mode setting.
• How to switch OFF Hotel-Mode.
• Intermittent colour.
• Field collapse normally with blank picture. (extract of circuit diagram attached) (20GR105073R PHILIPS repair tip)
• Does not switch on, standby LED OK.
• Tuning procedure.
• Line output transistor replacement.
• After switching on the CTV "EXT...1.2.3..." appears on the screen.
• Dead. Only hum from speakers. (extract of circuit diagram attached)
• Green picture with retrace lines. After a few restarts picture OK.
• High voltage transistor defective after a while.
• No start-up. intermittently (when cold). (picture attached)
• Does not start up at once from cold.
• +B very high. (picture attached) (service info for PHILIPS -20GR105073R)
• Stops working every 2 or 3 hrs. Only starts again after switching off and on again.
• No tuning bar when install button pressed and set not in hotel mode. (with circuit diagram extract)
• Intermittent colour.
• No picture. No sound. Switching on and off from Standby OK.
• Excessive vertical size.
• No audio.
• Replacement of surface mounted diode 6637. (with circuit diagram extract)
• Reduced vertical size. at top.
• No standby, humming and standby LED blinks.
• Display goes to F1 a few seconds after switching the set on.
• "Store" key does not work. (extract of circuit diagram attached) (20GR105073R PHILIPS repair tip)
• Sound returns gradually after channel change. (extract of circuit diagram attached)
• Poor sound, cannot be adjusted louder. When adjusting, sound cuts out. (with circuit diagram extract)
• Green picture. (picture attached)
• Power supply does not oscillate. (+ extract of circuit diagram)
• No start up, just a buzzing noise in speakers. (with circuit diagram extract)
• Quick hiccup. (part of circuit diagram displayed) (20GR105073R PHILIPS repair tip)
• Poor reproduction of copy protected tapes. (extract of circuit diagram attached)
• Microcomputers and screening plate.
• White balance adjustment.
• No function. Standby-LED lights up. Appliance switches on but no picture or sound.
• Lines across top of picture about 8" in first 100 lines. (+ extract of circuit diagram)
• Dead, very slight whistle from PSU. (20GR105073R tip from PHILIPS)
• How to reset microprocessor.
• Line tearing. on lower half screen. (extract of circuit diagram attached) (PHILIPS - 20GR105073R information)
• Set does not retune or program etc
• White screen with flyback lines. Excessive brightness which increases until PSU switches to protection mode. (picture attached)
• Picture displays lines and strange foldover effect at centre. (20GR105073R PHILIPS repair tip)
• Slow hiccup (part of circuit diagram displayed)
• CRT types.
• No SOP supply. (extract of circuit diagram attached)
• To release hotel mode (child lock).
• Bright flash on screen. No picture or sound. (picture attached)
• Switches off by itself. after a while. (with circuit diagram extract)
• Picture is poor with rippling on verticals. (picture attached)
• Search jumps on UHF. (20GR105073R tip from PHILIPS)
• Intermittent channel drift in UHF. Channel search OK. VHF OK. (20GR105073R PHILIPS repair tip)
• The tone (sound) tunes well, but the volume cannot be raised.
• No tuning or on screen tuning display. (20GR105073R PHILIPS repair tip)
• No functions. Standby LED flashes. Relay switches to ON.
• Tuning drifts. only on certain channels.
• Stations won't change. Picture and sound OK. Other functions OK.
• Drive for high voltage missing. (picture attached)
• Line tearing, especially with bright scences. (picture attached)
• Red picture. Flyback lines.
• No line start up; +95 available; +9V is about 4.5V. (with circuit diagram extract)
• No function, starts up from standby, then goes out.
• Humming, motor noise and other unusual noises. Normal picture. (20GR105073R tip from PHILIPS)
• Loosing colour during play-back of a video tape. (part of circuit diagram displayed)
• Green picture.
• The TV does not stop during the tuning phase.
• Stored channels drift off tune briefly after switch on. Crackle in sound.
• Error messages indicated by front display flashing. (+ extract of circuit diagram)
• Sound varies with picture content.
• Secondary main power supply OK except +9V at 5.8V (20GR105073R tip from PHILIPS)
• Processor numbers (changed).
• Vertical roll. (+ extract of circuit diagram)
• To put into hotel mode. (20GR105073R PHILIPS repair tip)
• No sound or picture. Low hum from speaker. (picture attached)
• Fizzling sound from speakers at start-up and intermittently picture jagged.
• Line chirps intermittently. Appliance does not start. Only hum from loudspeakers.
• No audio.
• Low audio. (extract of circuit diagram attached)
• To remove store/lock.
• No tuning, no remote volume control. (+ extract of circuit diagram)
• Intermittently no picture and sound at switch on. Buzz from speaker. (+ extract of circuit diagram)
• No start-up. Standby LED flashes .
• Control panel cover.
• Does not start. Slight buzzing in loudspeaker.
• U743 tuner replacement. (with circuit diagram extract)
• Blue picture. Coloured lines.
• Service manual correction. (with circuit diagram extract)
• Dim picture with Hanover bars visible. (extract of circuit diagram attached)
• Intermittently narrow picture, but corrects itself shortly after.
• Noise in sound. Mute does not function. (20GR105073R tips)
• Crackling and popping in sound after a short time.
• Line tearing and rope effect.
• No power supply start up in loaded condition (eg. with lamp).
• Right side of picture discoloured.
• Colour sync adjustment procedure.
• Sound varies with picture content.
• After working normally for a while the TV blocks in any position. The functions do not work.
• Blank or green raster. Flyback lines. Faint picture or normal picture. (picture attached)
• Slow start-up.
• Hotel Mode activates by itself. (picture attached) (service info for PHILIPS -20GR105073R)
• Modification at line transformer position 5530. (picture attached)
• Tripping. (with circuit diagram extract)
• No connection for headphone.
• Unstable tuning.
• Blank raster. Flyback lines. (part of circuit diagram displayed) (20GR105073R tips)
• Connection of a loop system to the TV.
• Difficult startup. Rattling sound from line output trafo.
• Sound varies with picture content.
• Limited volume. No channel search.
• No tuning. No channel lock. (picture attached)
• No transmitters to adjust and the sound is not controllable.
• Unstable tuning.
• Initial volume level is higher than maximum Hotel mode setting.
• Unable to tune or set volume in Prefix mode.
• No tuning. only on certain channels.
• Focus adjustment.
• PSU peeps +95 is ca 0,8v (20GR105073R tip from PHILIPS)
• No picture or sound but RCU works correctly. LED flashes when the handset is tried. (part of circuit diagram displayed)
• Very slight vertical foldover with interferences similar to EHT arcing, especially on very white scenes.
• No output from the chopper power supply which uses a junction FET, whose gate and source are at 12V while 300V is present at the drain. (with circuit diagram extract)
• No tuning.
• The switched-mode power supply cannot be loaded.
• Picture fails for a short time. (extract of circuit diagram attached)
• Does not stop on stations.
• Frame has shifted sideways. Appliance whistles and does not oscillate correctly. (picture attached)
• New IR receiver.
• Line output stage only starts up for a short time. (picture attached)
• Low 5V to micro chip. (picture attached)
• No colour and vertical black bar across screen.
• Low audio.
• Change of C2523.
• Skips channels during tuning. only on certain channels.
• Wavy picture. on the right.
• After operating for one hour it is no longer possible to switch over programmes not even from the front panel. Appliance must be switched on and off then it is possible to change channels.
• Green screen with flyback line. No picture. OSD OK.
• Chopper inoperative. (part of circuit diagram displayed)
• LED does not flash. Slight buzz in appliance. (+ extract of circuit diagram)
• No switch on. Weak whistling noise from PSU. LED is OFF.
• Memory content dropout at positions 4 and 5.
• Change of C2523.
• No picture. Audio OK .
• Colour disappears with VCR-scan (picture search). (with circuit diagram extract)
• No functions. when cold. (service info for PHILIPS -20GR105073R)
• Reluctant to start from cold (with circuit diagram extract)
• Dead. Strange noises from PSU/ line output transformer. (+ extract of circuit diagram)
• Searches for channels continuously. (+ extract of circuit diagram)
• Line down middle of screen. (+ extract of circuit diagram)
• Menu rolling. (picture attached)
• No OSD. Picture OK .
• Programs and PP-settings cannot be changed.
• Control micro processors.
• No voltage from PSU, computer does not work. (picture attached)
• Does not start up. Light buzz from loudspeaker. Standby LED produces one brief blink.
• How to de-activate Hotel-Mode:
• Lines on picture after approx one hour. It consists of a band of bright white lines about two inches wide. (with circuit diagram extract)
• No picture. No sound. Purring sound in loudspeaker. (part of circuit diagram displayed)
• Set goes accidentally into hotel mode.
• Print with linearity coil pos. 5800.
• Smeary, washed out picture with bent verticals. (with circuit diagram extract)
• Enter service mode.
• Sound varies with picture content.
• Unstable tuning.
• Poor sync. AGC fault.
• Trips. at start-up (intermittently). (picture attached)
• Tuning menu can not be called. All other functions OK.
• Bright flash on screen and no picture or sound after a few minutes. (extract of circuit diagram attached)
• Power supply fault finding. (part of circuit diagram displayed)
• No or intermittent start-up. (with circuit diagram extract)
• No picture. OSD OK .
• Vertical amplitude cannot be fully adjusted, TXT lines can be seen. (picture attached)
• Buzz in audio. No picture.
• Reluctant to start up from cold.
• Will not tune, drifts, colour disappears or interference on a certain channel. (e.g. channel 5 and 59)
• No function. Motorboating from PSU. TV starts up randomly. Intermittent fault.
• Does not regulate +95V.
• Whistling from PSU. (extract of circuit diagram attached)
• How to de-activate volume limiter.
• Appliance does not function with standby light flashing. (service info for PHILIPS -20GR105073R)
• Green screen and at other times no tuning. (extract of circuit diagram attached)
• No colour.
• Colour amplitude and phase adjustment procedure.
• Cannot change tuning or stored settings. (picture attached)
• 10V on 95V line. (with circuit diagram extract)
• Change of C2523.
• Volume goes to max. No volume control.
• Local controls inoperative. (service info for PHILIPS -20GR105073R)
• Noise in audio.
• Cannot be programmed and search does not function. Only limited volume adjustable. (PHILIPS - 20GR105073R information)
• Colours flickers and disappears.
• Switches to standby. (with circuit diagram extract)
• Low frequency noise on sound.
• Appliance hums slightly (no speaker) horizontal end stage and power supply transistor are ok. Unfortunately no service instructions available.
• Colours flickers and disappears.
• Volume can't be tuned down. No tuning with RC. (+ extract of circuit diagram)
• Rolling or jittering picture. (extract of circuit diagram attached)
• Picture appears slowly. (PHILIPS - 20GR105073R information)
• Occasionally appliance does not switch on from standby. No further functions are possible.
• Intermittent audio and picture. (+ extract of circuit diagram)
• Using a lamp as a load.
• To improve performance with prerecorded cassettes. (picture attached)
• R-Y and B-Y discriminator adjustment procedure. (picture attached)
• Initial volume level is higher than maximum Hotel mode setting. (20GR105073R tips)
• Picture shifted horizontally. (with circuit diagram extract)
• No colour. (extract of circuit diagram attached)
• Skips channels during tuning. (with circuit diagram extract)
• Buzz in audio (intermittently). (part of circuit diagram displayed)
• No start-up. when cold. (+ extract of circuit diagram)
• Volume varies. depending on picture content. (picture attached)
• Replacement of TDA7052 with a TDA7052A.