Need TV Repair Services in Nairobi?
Certified technicians dispatched to you — same day.
Diodes are semiconductor components that allow electrical current to flow in one direction only. In television circuitry they serve several critical roles: rectifier diodes convert AC to DC in the power supply, zener diodes regulate voltage levels, and Schottky diodes provide fast switching in power circuits. Diode failure — usually a short circuit caused by overcurrent — is a common consequence of power surge damage and typically causes the power supply board to fail. Replacement is a straightforward but skilled repair.
Identification tip: Diode types are marked with a part number on the component body. Common TV rectifier diodes (e.g. 1N4007, FR107, UF4007) are inexpensive and widely available. High-voltage diodes used in flyback circuits are more specialised.
| Diode Type | Application | Estimated Price (per unit) |
|---|---|---|
| 1N4007 rectifier diode | PSU rectification | KSh 10 – 30 |
| 1N5408 (3A rectifier) | Higher current PSU | KSh 15 – 50 |
| Zener diode (various voltage) | Voltage regulation | KSh 15 – 60 |
| Schottky diode (1N5819, SR540) | Fast switching PSU | KSh 20 – 80 |
| High-voltage diode (HER308, UF4007) | SMPS circuits | KSh 20 – 100 |
| Bridge rectifier module | PSU AC rectification | KSh 50 – 300 |
Note: Diodes are very cheap components — typically KSh 10–100 each. As with resistors, the diagnostic and labour cost far exceeds the part cost.
