TV Repair project

from Aurélie broken TV Gift.. (2022?)

Model Samsung LE32B652T4W

  • LCD panel: AUO T315HW02 V.3 (31.5″ FHD) with CCFL lamps (cold-cathode fluorescent backlight tubes), not LEDs.
    • Note: CCFL backlights are driven by an inverter inside the power supply (different from LED strips).

# Diagnosis

  • TV has power
    • red light showing
    • play sound when powered
  • screen is black
  • when lighten with a power light we can see some faint text (and see menu) that disapears when powered off

Likely fault: backlight

# Backlight

# CCFL backlight

This TV does not use LED backlight strips — it uses CCFL lamps driven by an inverter circuit inside the PSU.

So instead of LED backlight strips, you’ll be diagnosing:

✅ CCFL backlight lamps

These are fluorescent tubes inside the panel that light up the LCD.

✅ Backlight inverter

In this model the inverter circuitry is part of the power supply board (BN44-00261A). masterelectronicsrepair.blogspot.com

CCFL backlight inverter uses high voltage (hundreds of volts). If you’re not experienced with mains electricity, please get professional help.

CCFL inverters generate 600–1,500 V AC. Do not touch lamp outputs when powered.

# Next step

What to check

Power on the TV

Open the back cover

On the power supply board (BN44-00261A), find the backlight inverter output lines to the CCFL lamps.

📌 Often marked something like:

INV / CCFL / Backlight Enable

Tubes usually connect via white multi-pin connectors

What measured voltage should look like

You should see high AC voltage on the CCFL lamp outputs when the TV is turned on.

If this voltage is missing → inverter is dead.

# Check inverter enable signal (easy + safe)

On the power supply board (BN44-00261A) locate the connector from the main board.

Look for pins labeled similar to:

BL_ON

INV_ON

DIM

Measure with multimeter (DC volts)

TV ON

Measure BL_ON → should be ~3–5 V

# Inspect inverter section visually (very common failure)

Focus on the inverter area of the PSU:

Check for:

🔥 Burnt or cracked inverter transformers

💥 Swollen electrolytic capacitors

🔩 Cracked solder joints (especially transformer pins)

⚡ Burnt MOSFETs (near transformers)

📌 Cold solder joints on inverter transformers are extremely common on Samsung B-series TVs

👉 Re-soldering transformer pins often fixes the TV completely.

Cheapest ✔ No panel disassembly

Typical fixes:

Replace bad electrolytic capacitors

Replace inverter MOSFETs

Re-solder inverter transformers

Replace defective transformer

📌 Success rate: very high

# Other tips

# Led Backlight

# Power issue

not the case here

see Réparation d’un téléviseur SAMSUNG qui ne s’allume plus.

# Dissasembly

Written on December 27, 2025, Last update on March 20, 2026
tv broken project