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| Samsung UE Series TV Power Cycles in a Loop repair | |
|---|---|
| Device | Samsung UE Series |
| Affects part(s) | Logic Board |
| Needs equipment | |
| Difficulty | ◉◉◉◌ Hard |
| Type | Soldering |
Problem description
Device can be switched on with the remote control, relays for main power supply click on, splash screen appears. A few seconds later the main power supply clicks off. After a few seconds the main power supply clicks on again and the whole process repeats indefinitely.
Device can be temporarily "fixed" by bumping on the back of the device in certain locations, indicating an intermittent contact issue. But the problem will re-appear after a few minutes.
Some older LCD models like the LE40M86BD will power on, the display lights up and shows an image only to disappear a few seconds later as the screen turns off. After a long period of time doing this (even 1 hour) the TV will power on and stay on. The signals board has a tin shielding cover (with holes in it) and the capacitors underneath it gets very hot during operation. The reason the TV eventually starts is that the capacitors are rejuvenated by the heat generated from the silicon chips.
Symptoms
- Device can be switched on and relays for main power supply click on, splash screen appears. A few seconds later the main power supply clicks off. After a few seconds the main power supply clicks on again and the whole process repeats indefinitely.
Solution
This can be caused by a loose cable between power supply and mainboard. The cable is longer than needed, which can result in stresses due to kinks?
- Remove power cord.
- Remove screws that hold in back metal cover.
- Remove back metal cover.
- Visually inspect electrolytic capacitors (if they look like new, the fix may be very simple)
- Carefully unplug and re-plug the connectors of the cable that connects the power supply unit (e.g., L46X1Q_DHS BN44-00623B by Hansol Technics Thailand Co. Ltd; right-hand side) to the logic board (e.g., HIGH_X12_UNION, Model: BN41-01958, Code: BN41-01958A, left-hand side)
- Replace all the capacitors underneath the tin shielding cover and the TV might be fixed. The shield can also be heated first to check if heat will rejuvenate the aging capacitors and revive the TV.