Samsung UE50F6500 no picture but sound, LED backlight or T-Con board fault
User question
Samsung UE50F6500 zeigt plötzlich kein Bild mehr. Der Ton ist da?!
Artificial Intelligence Response
Direct answer to the question
- Most likely cause: failed LED backlight (open LED on a strip) or the LED-driver section of the power supply. Second most likely: T‑Con board (Timing Controller) or its supply.
- Quick way to separate them:
- Do a flashlight test: if you see a faint image, the LCD and video path work and the backlight (LEDs/LED driver) has failed.
- Unplug the mainboard-to-power-supply cable and apply mains: on most Samsung F‑series the backlight auto-lights. If it does, LEDs/driver are OK and the mainboard/BL_ON control is at fault; if it doesn’t, suspect LEDs or the PSU LED driver.
Detailed problem analysis
- How this TV generates an image:
- Power supply (PSU) provides 5 V standby, 12–13 V run rails, and a high-voltage constant-current output for the LED backlight.
- Mainboard decodes audio/video and sends “PS_ON” and “BL_ON/PWM” control to the PSU.
- T‑Con converts LVDS from the mainboard to panel timing/voltages (VGL/VGH/VCOM) that drive the LCD.
- LED strips (edge/backlight) provide illumination through diffusers; if any strip or LED goes open, the driver detects a fault and shuts all backlights off.
- Symptom mapping for “sound OK, no picture” on UE50F6500:
- Faint picture under flashlight → LCD and T‑Con work, failure is backlight LEDs or LED driver on PSU.
- Brief backlight flash at power‑on then darkness → typical of an open LED string; driver starts, sees overvoltage (no current), shuts down.
- No OSD even with flashlight and backlight never glows → suspect T‑Con (blown panel fuse, shorted IC) or no 12 V feed to T‑Con; less often mainboard video failure.
- Non-invasive checks (no tools):
- Power-cycle: unplug for 2–3 minutes; restart.
- Try Menu with room darkened + flashlight at a shallow angle.
- Switch inputs and sources; disconnect all HDMI to rule out CEC/handshake lockups.
- Board-level diagnostics (tools recommended: multimeter; ideally an LED backlight tester):
- With back cover removed, visual inspection: bulged electrolytics, scorching, cracked connectors, browned LED diffuser areas.
- Measure PSU rails relative to chassis:
- STBY ~5 V present in standby.
- PS_ON pin goes high (~3–5 V) when turning on; 12–13 V rail should rise and stay stable.
- BL_ON/ENA high (~3–5 V) and DIM/PWM (0–3.3 V PWM) when picture should be lit.
- LED+ output typically ramps well above 100 V when starting the strings; a ramp-and-collapse indicates open LEDs.
- “Auto-backlight” test: unplug the multi-pin cable from PSU to mainboard, apply mains. Many Samsung PSUs light the backlight by default; if LEDs light uniformly, the LED strips and PSU driver are likely fine—fault points to mainboard control (no BL_ON or 0% dimming).
- T‑Con checks:
- Confirm T‑Con fuse (often marked F1) has 12 V on both sides.
- If the fuse is open or there’s 0 V, trace back to the mainboard 12 V feed.
- If 12 V is present but no OSD under flashlight, T‑Con may be bad.
- LED strip confirmation:
- Safest is with a dedicated LED backlight tester: unplug the LED harness and drive each string; a non-lighting string = open LED/strip.
- Do not use multimeter diode mode (insufficient voltage).
Current information and trends
- For Samsung F‑series (circa 2013), aging LED strips are a very common failure after years of operation; single open LEDs trip protection and shut all backlights off.
- Many successful repairs replace the entire set of LED strips rather than single LEDs because:
- Mixing old and new LEDs often leads to uneven brightness and repeat failures.
- Aftermarket strip quality varies; reputable suppliers provide matched sets by panel code.
- Post-repair backlight current reduction (via service menu backlight/PWM or adding a small value resistor in the LED current sense path on the PSU) is often used to extend lifespan. Use caution: incorrect changes can cause artifacts or faults.
Supporting explanations and details
- Why you still have sound: the mainboard and audio path power up independently of the backlight; a backlight shutdown does not mute audio.
- Why the screen looks “dead”: without backlight, the LCD shutters modulate light but remain invisible; the flashlight test injects light so you can see the image.
- Why the LED driver shuts down: constant-current boost converter senses overvoltage/under-current (open circuit) and latches off for safety.
Ethical and legal aspects
- Safety: the PSU includes a PFC stage with a ~380–400 V DC bus and the LED output can exceed 100–200 V. Work de-energized, wait for capacitors to discharge, and use insulated probes.
- Environmental: consider replacing strips/boards rather than the entire TV to reduce e‑waste; recycle failed parts appropriately.
- Don’t bypass protections (e.g., jumpering current sense) as this risks fire or panel damage.
Practical guidelines
- Tools:
- Bright flashlight, Phillips screwdriver set, ESD strap.
- Multimeter (true RMS), LED backlight tester, plastic spudgers.
- Optional: suction cups and large, clean workspace if opening the panel.
- Repair paths:
- If flashlight shows image: replace LED strips (preferred) or repair the LED driver if it’s the culprit. Disassembly involves removing bezel, metal frame, diffuser sheets, and accessing strips—high risk of panel damage; photograph each layer and keep dust-free.
- If no image under flashlight but T‑Con fuse has 12 V: swap T‑Con board first (relatively inexpensive and simple). If unchanged, suspect mainboard.
- If auto-backlight test lights the panel: investigate BL_ON/PWM from mainboard; a mainboard swap is typical.
- Costs (typical ranges):
- LED strip set: ~€30–€80 / $35–$90.
- T‑Con board: ~€20–€60 / $25–$70.
- PSU or mainboard: ~€60–€150 / $70–$170.
- Professional repair: €120–€300 depending on region and part.
- Post-repair tip:
- Reduce backlight level in user settings and disable “Dynamic/Shop” modes to lower LED stress.
Possible disclaimers or additional notes
- The UE50F6500 exists with multiple panel codes; part numbers for PSU/Main/T‑Con/LED strips vary with the exact panel. Always order parts by the panel code printed on the LCD label, not just by TV model.
- Opening the panel to replace LED strips is unforgiving; if you are not experienced, consider a professional to avoid cracking the glass or mis-stacking diffuser sheets.
Suggestions for further research
- Obtain the service manual for your exact panel code for connector pinouts and voltages.
- Look up the PSU connector silkscreen (PS_ON, BLU_ON/ENA, DIM, 13V, GND) before probing.
- Search by panel code (e.g., CY-xxxxx) for the matching LED strip kit.
- Learn safe handling for large LCD panels and diffuser stacks; practice on a scrap set if possible.
Brief summary
- Do the flashlight test first. If you see a faint image, you almost certainly have a backlight/LED-driver failure; proceed to test LED strings and the PSU LED section.
- If no image even with a flashlight, check T‑Con power/fuse; try a T‑Con swap before suspecting the mainboard.
- A quick unplug of the mainboard from the PSU to see whether the backlight auto-lights is an effective discriminator between LED/PSU issues and mainboard control faults.
If you can, tell me:
- Do you see a faint image with a flashlight?
- Does the backlight flash briefly at power-on?
- Are you comfortable measuring voltages, and do you have a multimeter or LED tester?
- What panel code (sticker on the LCD) and board numbers do you have?
With those details I can give you exact test points and a targeted repair plan.
Disclaimer: The responses provided by artificial intelligence (language model) may be inaccurate and misleading. Elektroda is not responsible for the accuracy, reliability, or completeness of the presented information. All responses should be verified by the user.
User question
Zusätzlich zu den gemeldeten Aspekte wie Samsung UE50F6500 zeigt plötzlich kein Bild mehr. Der Ton ist da. Stelle ich fest, dass der Hintergrund etwas blau ist und mittig einen dunklen Streifen (ca. 1/3 von der Höhe). Im rechten, unteren Bereich tauchen mehre Balken wie ein Barcode, mit gleichen höhe der vertikalen gleichbreiten Streifen von ca. 4 mm. Das Standby Lämpchen geht dann wieder aus. Über die Fernbedienung kann man nichts steuern, Sourceauswahl, Menu. Es ist nichts zu sehen!
Artificial Intelligence Response
Direct answer to the question
Schlüsselpunkte
Detailed problem analysis
Geräteaufbau (vereinfacht):
Symptomdeutung:
Was spricht wogegen?
Theoriehinweis:
Current information and trends
Supporting explanations and details
Ethical and legal aspects
Practical guidelines
Possible disclaimers or additional notes
Suggestions for further research
Brief summary
User question
Wie kann man bei Samsung TV Model-Code: UE50F6500SSXZG die hintere Abdeckung anmachen?
Artificial Intelligence Response
Direct answer to the question
Detailed problem analysis
Current information and trends
Supporting explanations and details
Jede Schraube erst ansetzen, dann im Kreuzmuster handfest anziehen, um Verspannungen zu vermeiden.
Ethical and legal aspects
Practical guidelines
Possible disclaimers or additional notes
Suggestions for further research
Brief summary