MTS21M750 / MELECTRONIC [TV 55 (51) cm picture]

• Blows fuse. (with circuit diagram extract)
• Setting the decoder (RGB injection in the HF mode).
• Switches off by itself. depending on picture content.
• PSU transistor T60020 (BUZ90) fails after 1 sec (+ extract of circuit diagram)
• No teletext, menu cannot be activated. (part of circuit diagram displayed)
• Vertical streaks.
• Horizontal foldover. Switches to standby. after a few seconds.
• Picture is intermittently dark grey. OSD is ok when fault occurs, no text. No picture content. Not heat-, cold- or knock sensitive (part of circuit diagram displayed)
• Power transistor and resistor R60021 blow. (MTS21M750 tips)
• Unstable HT. (picture attached)
• How to activate/de-activate ECO switch.
• Picture geometry adjustment.
• Faulty TXT. intermittently.
• No h-drive out from TDA8374. PSU and standby OK. (part of circuit diagram displayed)
• Transient lines in picture. (MTS21M750 tip from MELECTRONIC)
• PSU fails.
• 50Hz or 60Hz switchover in AV mode.
• Dark screen, also through SCART socket. Teletext is OK. (with circuit diagram extract)
• Adjusting the AST start.
• Switches to standby but pulsates after start. (+ extract of circuit diagram) (MTS21M750 MELECTRONIC repair tip)
• Line BU is defective. (+ extract of circuit diagram)
• Black vertical beads in AV mode. Intermittently no picture content. (+ extract of circuit diagram)
• Slow start-up.
• Switch transistor S/C. (picture attached)
• Starts, stops after a short time and starts again. No picture. No sound. Mains switch comes out.
• Enter service mode.
• Only mix mode in TXT.
• No TXT. intermittently. Blank raster. intermittently.
• White balance adjustment.
• Adjusting the status display. (MELECTRONIC - MTS21M750 information)
• T60020 is S/C. (+ extract of circuit diagram)
• Adjusting the channel duration OSD.
• BUZ90 and two safety diodes D60029 and 30 (BYT54M) are defective. PSU only pulses (with circuit diagram extract)
• Usys approx. 8V.
• AGC adjustment. (part of circuit diagram displayed) (MELECTRONIC - MTS21M750 information)
• Calling up the timer.
• Adjusting the OSD position.
• Twitching hum in picture on band I, only when cold. (with circuit diagram extract)
• Switches to standby. intermittently (after a while).
• Focus adjustment. (MTS21M750 tips)
• Failure of: chopper FET, bridge rectifier and diodes D60023 and D60024. Occasionally IC also fails. (part of circuit diagram displayed)
• Reduced horizontal size. (part of circuit diagram displayed)
• Calling up the AFC recovery "ON/OFF".
• RGB output stage or video text functions fail.
• Calling up SERVICE mode at HOTEL mode ON.
• How to enter tuning mode.
• Failure of transistor T21501 (PBF259RS). (+ extract of circuit diagram)
• Difficult to start up. Then half a picture appears on screen with flyback lines. (+ extract of circuit diagram)
• Line focus adjustment. (+ extract of circuit diagram) (MTS21M750 tip from MELECTRONIC)
• Protective circuit starts up if picture content suddenly changes. (+ extract of circuit diagram)
• Excessive brightness. Flyback lines. (+ extract of circuit diagram) (MTS21M750 tips)
• No REC.
• Bright raster. Flyback lines. intermittently.
• No functions. (extract of circuit diagram attached)
• IR data programmer adjustment.
• Excessive horizontal size.
• Value of resistor R60022. (with circuit diagram extract)
• Stuck in standby. (+ extract of circuit diagram)
• Replacement of IC UC3843 or UC3843N. (part of circuit diagram displayed)
• Enable Hotel mode.
• Coloured lines. on upper half screen. (MTS21M750 tip from MELECTRONIC)
• Picture up in screen and goes narrow. (part of circuit diagram displayed)
• No colour. (part of circuit diagram displayed)
• Switches to standby (intermittently). (+ extract of circuit diagram)
• +A not adjustable. (extract of circuit diagram attached)
• Vertical fault. (+ extract of circuit diagram) (MTS21M750 tips)
• Switches to standby. (picture attached)
• Switches to standby. after a few seconds. (part of circuit diagram displayed)
• Adjusting the max. program no.
• Unstable picture. No colour. intermittently. (part of circuit diagram displayed)
• Switches to standby. after a few hours.
• No colour. via SCART. (MTS21M750 tip from MELECTRONIC)
• Does not read disc. Mechanical noise.
• Occasionally no switch on with power supply switch. (especially not with low room temperatures). (with circuit diagram extract)
• No raster.
• Failure of vertical end stage IC (TDA8356). (picture attached)
• Setting the line focus.
• Service menu adjustment.
• No reset. (picture attached)
• OSD runs vertically when cold but also intermittently in operation mode. Switches to standby. (part of circuit diagram displayed)
• No TXT. (MTS21M750 tip from MELECTRONIC)
• Starts up with only half a picture. Flyback lines on top of screen. (extract of circuit diagram attached)
• +A voltage adjustment. (picture attached)
• Storing the analogue values.
• No start with mains switch. (extract of circuit diagram attached)
• Dark screen.
• Shuts down. after a while.
• Vertical collapse. (+ extract of circuit diagram)
• No start-up (intermittently). (picture attached)
• No picture. via tuner.
• Disable hotel mode.
• Mains fuse SI60001 blown. (with circuit diagram extract)
• Excessive vertical size.
• Can not be switched on intermittently (especially at low room temperature).
• Red picture. Flyback lines.
• No vertical deflection. (extract of circuit diagram attached)
• No picture. No TXT. (part of circuit diagram displayed)
• No picture. intermittently. Flyback lines. (extract of circuit diagram attached)
• Tripping. (extract of circuit diagram attached)
• No TXT. No OSD on program sites. Via AV OK, but OSD shifts to the left.
• No operating voltage at line output transistor.
• Dead. (picture attached)
• PB of the connected IR headphones fails after switch on of the TV for approx. 1 min. Passively working headphones are ok. (picture attached)
• Power problem.
• Wrong display in stand by mode after changing processor.
• White lines on upper picture edge. (with circuit diagram extract)
• No HT control. (extract of circuit diagram attached)
• No luminance.
• Calling up the contrast control.
• No functions. LED lit. .
• No start-up (when cold). (with circuit diagram extract)
• Switches to standby. after a few minutes. (part of circuit diagram displayed)
• Horizontal lines on screen up to sync tearing and sound crackling when cold for the first 5 mins. (+ extract of circuit diagram)
• Volume is max, brightness, contrast and colour min after switch on. (+ extract of circuit diagram)
• T21501 fails.
• Picture twitches. Horizontal size varies. depending on picture content. (picture attached)
• Noise in audio.
• Raster foldover. Lines at bottom of picture. (part of circuit diagram displayed)
• No auto programming. (+ extract of circuit diagram)
• Horizontal collapse.
• Chopper MOSFET IRFBC40 fails. (extract of circuit diagram attached)
• Switches to protection mode. after start-up. (+ extract of circuit diagram)
• AFC adjustment.
• Appliance starts up for a short while. Sound is mostly OK but picture is dark. After approx. 1 second appliance falls back to standby and the it can be started up again. Sometimes a white picture appears at start up (no content) from the top to approx. 1 (picture attached) (MTS21M750 tip from MELECTRONIC)
• Contrast decreases if Audio key is pressed. At program switch over one program is skipped. (+ extract of circuit diagram)
• No horizontal deflection.
• Low brightness. Low contrast.
• PSU defective. (extract of circuit diagram attached)
• No function. Transistor PSU defective. (extract of circuit diagram attached)
• Setting the optimal values.
• Line BU doesn't oscillate. (picture attached)
• After approx one hour, approx 1cm horizontal lines appear on screen then picture becomes blurred and appliance switches to standby.
• Trips. depending on picture content.
• Setting the decoder mode.
• No start-up. (extract of circuit diagram attached)
• Weak contrast. (with circuit diagram extract)
• Screen grid voltage adjustment.
• Switches to standby. intermittently. (picture attached)
• No channel storing.
• Lines are pulled down on top. (+ extract of circuit diagram)
• Picture width varies depending on beam current charge. (extract of circuit diagram attached)
• Intermittently power switch disconnects. (extract of circuit diagram attached)
• Crackling of the sound when cold for the first 5 mins and horizontal lines on screen to the limit of sync tearing. (+ extract of circuit diagram)
• Distorted picture on channel 16. On other channels only 2 thin white lines. (with circuit diagram extract)
• Starts briefly. Mostly with sound but dark picture. (picture attached)
• How to deactivate eco switch.
• +A too high. (MTS21M750 MELECTRONIC repair tip)
• No start-up. intermittently (when cold). (+ extract of circuit diagram)
• No text blanking.
• "E"appears on OSD instead "OK". (MTS21M750 tip from MELECTRONIC)
• E message when setting memory.
• No picture. on the right.
• Loud crackling. (part of circuit diagram displayed) (MELECTRONIC - MTS21M750 information)
• No audio.
• Disable child lock.
• Horizontal line. at top. (part of circuit diagram displayed)
• AFC reference adjustment. (+ extract of circuit diagram)
• Pulsates. Middle of screen is out of focus.