Your LG OLED suddenly switches off on its own, the standby LED goes completely dark, and it only starts up again after you've unplugged the TV from power for one to two minutes? Then it's very likely not the expensive display or the mainboard that's broken, but the power supply (power-supply board). The good news: this exact defect can be repaired affordably and with a warranty.
The Typical Symptoms of a Power Supply Defect
LG OLED TVs of the C series (C1, C2, CX) show very characteristic behavior with a faulty power supply. If you observe one or more of these symptoms, it strongly points to the power supply:
- Standby LED goes dark: The red standby LED on the front goes completely off. The TV responds neither to the remote nor the power button — until you disconnect it from power for one to two minutes. After that it briefly starts again but often fails once more.
- TV shuts off spontaneously: The picture switches off without warning during operation, or the TV won't boot at all in the morning.
- HDMI self-test fails (NG): The internal self-test (via the service menu or at power-on) reports "NG" (No Good) on the HDMI path, even though the panel is intact and shows no image errors.
Power Supply or Mainboard? How to Narrow It Down
Before commissioning a repair, a quick self-diagnosis pays off. Power supply and mainboard defects show different patterns:
| Observation | Likely Cause |
|---|---|
| Standby LED dies, only works after unplugging | Power supply |
| Spontaneous shutdowns, no boot | Power supply |
| HDMI self-test reports NG, panel visually intact | Power supply |
| Standby LED stays on but no picture / hangs at LG logo | Mainboard |
| Image errors, lines, half a picture | Mainboard / T-Con / panel |
Rule of thumb: if the standby LED goes off and only a brief power disconnect helps, the power supply is almost always to blame. If the LED stays on but the TV shows no picture, it's usually the mainboard.
What Does the Power Supply Repair Cost?
A power supply replacement at LG service or independent workshops quickly costs €150–250. At ampario you get the LG OLED power supply repair at a flat rate of €75 — including a 12-month warranty on the performed repair. Important for clarity: this service covers the power supply board only. Mainboard or T-Con defects are not included.
→ To the LG OLED power supply repair (€75, 12-month warranty)
Which LG Models Are Affected?
The typical power supply defect mainly occurs in the OLED C series: C1, C2 and CX in sizes 48", 55", 65" and 77". Specifically affected are models such as the OLED65C17LB (LG65C17LB) and identical variants.
Repair Yourself or Have It Repaired?
The power supply sits behind the back panel of the TV and is screwed and connected to the mainboard. Those with electronics experience can swap a matching replacement power supply themselves — suitable boards are available used and new.
View replacement power supplies for LG OLED on eBay
If you don't trust yourself with the procedure or want a warranty, the flat-rate repair is the safe choice: you save versus workshop prices and get a 12-month warranty on top.
Conclusion
If your LG OLED's standby LED goes dark and it only works again after a brief power disconnect, it's almost always the power supply and not the display that's defective — a comparatively inexpensive problem. Instead of searching forums, you can have the defect fixed directly at a flat rate of €75 with a 12-month warranty.