LTV74928NS / LENCO [TV]

• Switching transistor in primary PSU is S/C.
• Stretched picture. (picture attached)
• Vertical foldover at top and bottom. (part of circuit diagram displayed)
• Standby is red and becomes green for 2 secs after switch on.
• Compressed picture at the top.
• Channel shifts after station is changed. After retuning, everything is OK.
• PSU pulsates quickly, audible via speaker. (part of circuit diagram displayed)
• Reduced horizontal size. Standby LED flashes . (LENCO - LTV74928NS information)
• Noise from PSU. Strong hiccup. (with circuit diagram extract)
• Switches to standby when picture appears or picture pulsates slowly via AV or at low brightness.
• No picture (intermittently).
• Picture disappears, intermittently.
• Picture in only one colour with flyback lines.
• No start-up. Standby LED tries to go green then goes back to red.
• Grey screen. Audio OK .
• Low contrast.
• Shuts down after start up. Led blinks red/green a few seconds.
• Picture shifted to the right. No colour. (with circuit diagram extract)
• Excessive height. Foldover at top. Lines missing at top of picture. Different coloured vertical stripes across picture. (picture attached)
• Slight flicker after five mins, worsens as time goes on. Colour flickers ON/OFF. (part of circuit diagram displayed)
• Does not always switch on. Pumps after switch on.
• Programs are not stored after switch off.
• Stuck in standby. Squealing from PSU. (LENCO - LTV74928NS information)
• No luminance. (picture attached)
• Blank raster. (service info for LENCO -LTV74928NS)
• Does not switch to standby.
• No audio in SECAM L mode.
• Switches to standby at switch on, LED turns green for a sec.
• Snow in picture. (extract of circuit diagram attached)
• Line transistor blown shortly after switch on. (picture attached)
• Weak contrast. (part of circuit diagram displayed)
• Slightly cramped blank raster with flyback lines. In centre of raster there are coloured lines, slight E/W bow. (with circuit diagram extract)
• Only one primary colour with flyback lines.
• No video signal on screen, picture dark, OSD display OK.
• No colour. (with circuit diagram extract)
• Piecrusting in picture. (service info for LENCO -LTV74928NS)
• PSU pulsates. LED blinks . (extract of circuit diagram attached)
• No audio. in NICAM . (LTV74928NS LENCO repair tip)
• Picture quivers depending on brightness.
• Vertical fault.
• After start-up front LED is red, becomes green shortly and then red again. Dummy load lamp lights up shortly and then goes out. (LTV74928NS tips)
• Dead. (part of circuit diagram displayed)
• No picture. after warm-up. Audio OK .
• Power supply problems.
• Standby OK, green LED flashes twice briefly after start up attempt and goes to standby.
• Defective Q605 (BU508AF) line output transistor. (picture attached)
• No start-up from standby. LED is red .
• No picture. No OSD. Audio OK . (picture attached)
• Slow start-up. (+ extract of circuit diagram)
• Clicking noise. (with circuit diagram extract)
• Bent verticals.
• Comes on in standby, then if power button pressed blinks pale green.
• Intermittent picture and audio or does not find channels.
• Shuts down (intermittently).
• Dead. Standby LED flashes . (+ extract of circuit diagram)
• No start-up. LED is red . Clicking noise. (extract of circuit diagram attached)
• Picture size varies with picture content.
• No TXT (intermittently). (extract of circuit diagram attached) (LTV74928NS tip from LENCO)
• LED flickers. Light rhythmical noise, otherwise no function. (LTV74928NS tips)
• Reduced vertical size.
• Stuck in standby. Green LED flashes .
• Black screen. Audio and OSD OK .
• No picture (dark with barely visible spots). (with circuit diagram extract)
• BU2508D fails immediately at switch on.
• No TXT. (picture attached)
• R809 blown. (with circuit diagram extract) (LENCO - LTV74928NS information)
• Tripping. at start-up. (LTV74928NS LENCO repair tip)
• Clicking noise. after start-up. (picture attached)
• Vertical collapse. after a few minutes. Flyback lines. on upper half screen. (part of circuit diagram displayed)
• No front panel function.
• Tuning drifts. (extract of circuit diagram attached)
• Tripping. (+ extract of circuit diagram)
• Dead. LED is green.
• No startup. LED lights up at switch-on.
• To avoid anode voltage peaks. (+ extract of circuit diagram)
• Picture appears for several secs, then becomes dark and switches to protection. Sound OK. (LTV74928NS LENCO repair tip)
• PSU transistor fails at start-up. (with circuit diagram extract)
• PSU pulsates. in standby.
• Flyback lines. at top. (picture attached)
• No TXT just number 100 in the left corner.
• No deflection. Switches on with RC, display changes to green. Standby display available.
• Black stripes in white picture areas.
• Operates in short bursts. (LTV74928NS LENCO repair tip)
• Excessive brightness. Flyback lines. (part of circuit diagram displayed)
• Vertical collapse (intermittently).
• Picture shifted vertically. at bottom.
• Excessive horizontal size. Pincushion distortion. on sides. (extract of circuit diagram attached) (LENCO - LTV74928NS information)
• Audio output chip IC100 fails repeatedly.
• No functions. (part of circuit diagram displayed)
• Washed out picture. (extract of circuit diagram attached)
• BU2508 fails.
• Line BU transistor becomes hot.
• No start-up from standby. Green led flashes twice then switches to red.
• Line BU508A fails again immediately.
• Picture appears briefly but resorts to four horizontal lines. Sound OK. (part of circuit diagram displayed)
• Intermittently Q605 blown. (picture attached)
• Dead. Standby LED does not light. (extract of circuit diagram attached)
• Relay trips. (with circuit diagram extract)
• Dark picture. (extract of circuit diagram attached)
• Appliance fails and can only be started after a long time.
• Chopper transformer fails.
• Slow start-up. No start-up. intermittently.
• Wavy picture. on sides. (service info for LENCO -LTV74928NS)
• PSU ticks in standby and hisses in full load mode.
• Flickering picture. Bent verticals. (part of circuit diagram displayed)
• Whistling.
• Blurry picture. (picture attached)
• Over/under scan.
• White, bright screen with flyback lines.
• Blank screen with 3 coloured (R G B) lines across screen.
• Vertical end stage line.
• Appliance goes to standby if switched on with RC. Standby LED flashes green.
• Sizzling at start-up.
• Switches to standby intermittently. Comes on with RC but switches off after a while.
• Clicking noise. in standby. (+ extract of circuit diagram)
• Ripple on verticals.
• No horizontal drive at pin 40 of deflection processor. (picture attached)
• Excessive horizontal size. intermittently. E/W fault. (extract of circuit diagram attached)
• Poor picture. (picture attached)
• Hum bar. No RC functions. (part of circuit diagram displayed)
• At power up green LED is on for 2 secs, then flickers, set goes to standby. (+ extract of circuit diagram)
• E/W fault. Screeching noise. Line output transistor fails repeatedly.
• Chirping. at start-up. Trips. (extract of circuit diagram attached)
• White retrace lines on screen. (extract of circuit diagram attached)
• Snowy raster. Reduced width. No tuning. Unable to access SERVICE mode. Locks up if picture menu entered.
• Picture lost, then screen is black and RGB test lines moving in top half of screen.
• HV sparkling. (+ extract of circuit diagram)
• Shuts down. after start-up.
• Bright green raster with flyback lines. (with circuit diagram extract) (LENCO - LTV74928NS information)
• Shuts down. after a few seconds. HV OK. .
• Adjustments in service menu.
• No picture. Bright raster (after a few minutes). (picture attached)
• Negative picture. (part of circuit diagram displayed)
• Reduced vertical and horizontal size. (+ extract of circuit diagram)
• Insufficient height, about 3" down at top.
• LED blinks green.
• Tripping. LED blinks .
• No tuning. Poor synchronisation. Shifted phase.
• Locking codes misfunctioning.
• PSU pulsates. Switches to standby. after a while.
• Occasionally slight flashover in the picture.
• R914 is defective. (+ extract of circuit diagram)
• Black screen with three colour lines. Sometimes half a picture appears.
• Goes to standby, when pressing Volume, Mute or Menu buttons.
• Bright picture. (picture attached)
• Dead. LED blinks .
• Flyback lines. (part of circuit diagram displayed)
• Blue picture, no drive. Sound OK.
• Mains transistor fails immediately again. Netztransistor stirbt sofort wieder
• White screen. Retrace lines. (part of circuit diagram displayed)
• Picture collapses intermittently with E/W fault. White line in the middle. Sound crackles.
• No functions. LED is green.
• No picture, no sound. Standby diode flashes briefly green at switch on.
• Picture flickers with 3 coloured lines in upper side of picture.
• E/W fault. Switches to protection mode.
• Dead. Power LED lit . (+ extract of circuit diagram)
• Excessive HV. (+ extract of circuit diagram)
• Reduced horizontal size. Audio OK .
• Spots in picture. in the centre. (+ extract of circuit diagram)
• No or poor synchronisation. (+ extract of circuit diagram)
• Voltage Usys is only 35V.
• Excessive operating voltage.
• Reduced horizontal deflection. Reduced vertical deflection. Vertical foldover. at top and bottom.
• No front panel function. RC OK.
• No picture in PIP mode. (+ extract of circuit diagram)
• Pincushion distortion. (picture attached)
• Picture reduced horizontally in 16/9 and 4/3 mode.
• Disable hotel mode.
• D611 fails. Q605 becomes hot.
• E/W fault (after a while).
• Excessive blue. (+ extract of circuit diagram)
• Picture collapses. Shock sensitive.
• Shuts down. intermittently. Burning smell.
• No start-up. LED is red after operating mains switch. If switched on (via program key on user control or RC) LED lights green and then goes off.
• Pulsating picture. Shuts down. (with circuit diagram extract)
• Low HT. (with circuit diagram extract)
• E/W fault. intermittently.
• Red standby light changes to green then switches back to red.
• Horizontal line. in the centre. (part of circuit diagram displayed)
• No OSD. (picture attached)
• Picture and sound interference.
• Moire or line in picture with some band 1 stations (eg. channel 4) on certain aerial equipment.
• R717 (2K2) burnt repeatedly.
• Leaking in HT transformer.
• Switches to standby. after a few seconds. LED is green.
• No functions. Standby LED flashes .
• Switches to protection mode (after a while).
• White vertical stripes at upper picture edge. Picture becomes blank after a while.
• Picture too small. Distorted picture. (with circuit diagram extract)
• Picture twitches. Horizontal cogging. (LTV74928NS tip from LENCO)
• Picture foldover. Switches to standby.
• Dark picture. Colour varies. Colour flickers.
• Shuts down (after a few seconds).
• Vertical collapse. (+ extract of circuit diagram)
• No picture. Audio OK . (extract of circuit diagram attached) (LENCO - LTV74928NS information)
• Switches off from standby, LED is briefly green, then goes back to red. (LENCO - LTV74928NS information)
• Transformer failure.
• Q802 is S/C. (extract of circuit diagram attached)
• No line drive. (part of circuit diagram displayed)
• No functions. when cold.
• Picture too small.
• Stuck in standby. (part of circuit diagram displayed) (LTV74928NS LENCO repair tip)
• No signal (intermittently).
• Bright horizontal stripes.
• Goes off with a bang and bright light from the inside.
• Does not accept SCART input. (+ extract of circuit diagram)
• Blue screen.
• Colour varies. Flickering picture. (picture attached)
• Burst electrolytic capacitor C829 (47uF/160V).
• Picture too large. E/W defective.
• PSU pulsates. (+ extract of circuit diagram)
• Tripping sound from power supply. (extract of circuit diagram attached)
• Severe picture bowing after a minute or so. (LTV74928NS tip from LENCO)
• S/C in mains transformer. (with circuit diagram extract)
• Grey picture with flyback lines. (LENCO - LTV74928NS information)
• Enter service mode.
• White screen. (part of circuit diagram displayed)
• Ticking noise. No start-up. (part of circuit diagram displayed)
• Horizontal line.
• IC (TDA6108JF) fails after 12 hours operation.
• No tuning. (part of circuit diagram displayed) (LTV74928NS tips)
• Picture is OK, but it is necessary to readjust G2 at each start-up, otherwise screen becomes black.
• E/W fault. (+ extract of circuit diagram)
• Line output transistor fails repeatedly.
• Only UHF.
• Horizontal lines.
• No horizontal deflection. (picture attached)
• PSU blown. (LENCO - LTV74928NS information)
• BU2508AF fails intermittently. (with circuit diagram extract) (LTV74928NS tip from LENCO)
• No HV. (picture attached)
• No picture. intermittently (after a while). Faulty TXT.
• Picture width is too low and perhaps smoke develops. (picture attached) (LTV74928NS tips)
• Blank raster with 2 red, green and blue horizontal lines, approx one third down screen. (+ extract of circuit diagram)
• LED blinks, then switches to standby.
• Distorted picture (N/S), like in 16:9 format. Bars on top and at the bottom.
• Ticking noise from speaker in standby (Burst mode). (part of circuit diagram displayed)
• Dark picture with three coloured lines in upper third. Sound OK. (part of circuit diagram displayed) (LTV74928NS tip from LENCO)
• No start-up. LED turns green then switches back to red when RC command is sent.
• No contrast. at start-up.
• Reduced horizontal deflection.
• Power supply fails. Loud noise in the chopper.
• Takes long time to appear. Comes up quicker if first anode control adjusted. (extract of circuit diagram attached)
• Distorted sound. Volume cannot be adjusted.
• Green picture. Flyback lines.
• No start-up from standby. LED flickers .
• Switches to standby. after a few seconds. (with circuit diagram extract)
• Dark picture. Raster OK .
• Dark picture. OSD OK .
• No E/W correction.
• No function. PSU is dead.
• Line output transistor and TDA4605 is also defective.
• No adjustments are possible.
• Faulty OSD. (+ extract of circuit diagram) (LTV74928NS LENCO repair tip)
• Narrow, bowed picture. E-W faulty.
• Standby LED flashing green. (part of circuit diagram displayed)
• Line output stage (BU2508D) fails. R629 (2R7) burnt.
• Black screen.
• Moire on band 1.
• Low brightness.
• LED lights briefly green after switch on. PSU starts up but appliance goes back to standby.
• Black edges on top and at the bottom. Picture is available though all adjustments are set to minimum. Cannot be adjusted and no storage.
• Excessive horizontal size. (with circuit diagram extract)
• Power supply blown. (+ extract of circuit diagram)
• No PIP. (+ extract of circuit diagram) (service info for LENCO -LTV74928NS)
• No picture. Raster appears at start-up.
• No vertical deflection. (+ extract of circuit diagram)
• No start-up. Standby LED lit .
• Vertical lines. (+ extract of circuit diagram)
• Poor East/West correction. (extract of circuit diagram attached)
• IC802 (MC44604P) fails repeatedly.
• Low audio. (+ extract of circuit diagram)
• BU2508AF is S/C. (extract of circuit diagram attached)
• Reduced E/W on all widescreen scan formats. (picture attached)
• No horizontal or vertical deflection (intermittently).
• Reduced horizontal size. Pincushion distortion. on sides. (picture attached)