This guide in 1-2-3
- Diagnose: Do the flashlight test, power-cycle at the wall and note any standby-light pattern.
- Compare: Backlight and board jobs are often worthwhile; a cracked panel rarely is.
- Hire: Ask about a full backlight set, board repair vs. replacement, and how the TV is transported.
Safety first: Never take the back off a TV. Parts on the power board can hold a dangerous charge long after it’s unplugged — internal work is for qualified technicians only.
What’s Wrong? Symptoms and Usual Causes
“The screen’s gone” is often a cheaper fault in disguise. The common ones:
| Symptom | Common causes | Who should handle it |
|---|---|---|
| Sound plays, picture is black | Failed LED backlight strips or backlight driver; occasionally the main board | Technician (try the flashlight test first) |
| Won’t switch on, standby light flashes | Power supply board, main board, or a backlight short tripping protection | Technician |
| Lines across or down the picture | Loose or damaged ribbon cable, T-con board, or the panel itself | Technician |
| Strange colours, ghosting or double image | T-con board or cable fault, picture settings | Reset settings yourself; repairs by a technician |
| Cracks or spreading black blotches | Physical damage to the LCD/OLED panel | Get a quote — often replacement |
| One input shows “no signal” | Source device, HDMI cable or input port | Try another cable and source first |
Safe Checks You Can Do First
You don’t need to open anything for these:
- Try the flashlight test
With sound playing, hold a torch close to the screen in a dark room. A faint image means the panel probably works and the backlight is the likely fault.
- Power-cycle at the wall
Unplug for a few minutes, then plug straight into a wall socket rather than an extension lead.
- Open the TV’s own menu
If the menu looks fine but one input doesn’t, test a different cable or device.
- Count the standby flashes
Note any pattern — some brands use it to signal the type of fault.
When to stop: Don’t remove the back panel or try board repairs — capacitors can hold a dangerous charge after unplugging.
Backlight or Panel?
Mixing these two up — innocently or not — is the costliest misunderstanding in TV repair.
Often worth fixing
Backlight failure
Sound and channel changes work but the picture is dark. If the flashlight shows a faint image, the panel is usually healthy and the LED strips behind it have failed. Ask whether the whole set of strips will be replaced — the rest are the same age.
Physical damage
Broken panel
Cracks, spreading black areas or bleeding colours mean the panel itself is damaged. Replacement panels are expensive or unobtainable, and the price often approaches that of a new TV.
Board Repairs and Getting It There Safely
Most TVs have a power supply board, a main board and a T-con (timing controller) board. If yours needs workshop time, protect the screen on the way.
- Power supply board
Some faults can be repaired on the board instead of replacing it. Ask which you’re being quoted for, and why.
- T-con board and ribbon cables
Lines, ghosting or odd colours are sometimes cured by reseating a cable or swapping the T-con — check this before a panel is condemned.
- Upright and padded
Panels can crack if carried flat or flexed. Ask how the TV will travel, and use the original box if you kept it.
- Photos before it leaves
Take clear, dated photos of the screen and casing so any damage in transit can be identified.
What to Ask on the Phone
Before agreeing to a visit or a collection:
Q1: “What’s your diagnostic fee, and is it credited if I go ahead?”
Get the figure before you book so there are no surprises.
Q2: “Will you replace all the backlight strips or just the failed one?”
Replacing the full set usually lowers the chance of another failure soon after.
Q3: “Can the board be repaired, or only replaced — and what does each cost?”
Knowing both prices lets you compare quotes properly.
Q4: “How will the TV be moved, and is it covered while you have it?”
Get collection, return and any transit cover terms in writing.
Fix It or Replace It?
TVs have become much cheaper, so compare carefully:
Price a similar new TV
If the repair is a large share of a comparable new set — typical for panel damage — replacing usually wins.
Age and features
An older set may lack current apps, HDR or streaming support even once it’s working again.
Warranty and insurance
Retailer, manufacturer or card extended warranties and home insurance may cover faults or accidents.
Recycle the old one
If you replace it, use an electronics recycling or retailer take-back scheme.
Before You Pay: Check the Picture
Display check
Before final payment- Show a full-screen white and a grey image to check the brightness is even, with no dark patches or bright spots.
- Watch a few different programmes for lines or colour problems.
- Test every HDMI input you use, the sound, Wi-Fi and the remote.
- Inspect the casing for new damage and take the itemised invoice with parts, labour and warranty terms.
Where to go next
General information, not a diagnosis of your device. 123 Drivers Guide doesn’t carry out repairs or recommend particular businesses. Follow the manufacturer’s instructions, and leave electrical, gas and refrigerant work to a qualified technician.