LG 65CX TV that wouldn't power on: two failed X2 capacitors on the power board

At a glance

• Device: the power board from an LG 65CX TV (board LGP65CX-200P), posted on its own
• Fault: the TV would only power on after a hard reset and a five minute rest. Then it stopped powering on at all.
• Cause: two X2 capacitors on the power board, C601 and C602, had lost most of their value. Both should be 820 nF. They measured 105 nF and 505 nF.
• Fix: replaced both with new 0.82 µF X2 capacitors
• Result: the board tested fine on the bench
• Cost to the owner: £49 flat, including the parts and tracked return postage

The fault

The owner had been living with a TV that only started after a hard reset and a five minute rest. Then it stopped coming on at all. A fault that gets worse over time like that is typical of a part that's slowly drifting out of spec, so the power board was the place to start.

The owner booked our TV power board repair and posted just the board, so the TV itself stayed at home.

What we found

The two capacitors marked C601 and C602 are X2 film capacitors, the yellow blocks in the photo. Both are rated 820 nF. Out of circuit, one measured 105 nF and the other 505 nF, so they had lost most of their value. Film capacitors like these can lose capacitance with age, and these were far enough gone to stop the board working properly.

The fix

We replaced both with new 0.82 µF (820 nF) X2 capacitors.

The result

With the new capacitors in, the board tested fine on the bench. The job came to the flat £49, with the parts included, and the repair carries our 90 day warranty on the workmanship.

We can only test a power board on the bench, not inside the TV, so a fault somewhere else in the set can't be ruled out. We say that before booking, and the warranty covers our work on the board.

Questions about this fault

Why does my LG TV only turn on after being unplugged for a while? That pattern often points to the power board, where a part is on its way out and only works some of the time. On this board it was two X2 capacitors that had lost most of their value.

Do I need to send the whole TV? No. Post just the power board. It's much cheaper to post, and the TV stays at home.

Can you tell if it's the power board before I send it? Not for certain without testing it, but the symptoms are a good guide. Get in touch with what the TV is doing and we'll tell you honestly whether the power board is the likely cause.

TV won't power on?

Our TV and monitor power board repair is £49 flat, no fix no fee, with tracked return postage included. Post just the board.