This case study demonstrates how a methodical approach can pinpoint issues even without a schematic.
If you have successfully repaired a "Wannien 101v0" board, please contribute to the community. Share your findings, a reverse-engineered schematic, or even just high-resolution photos. Your contribution might be exactly what another technician needs to bring a device back to life.
If you are repairing a device utilizing a Wannien 101V0 board—such as an industrial automation terminal or standard display monitor—use this sequential diagnostic approach: Faulty Electrolytic Capacitors ("Capacitor Plague") wannien 101v0 power supply schematic
Ensure all connectors are secure and free from corrosion 1.2.2. 3. Accessing the Schematic Diagram
Measure the input voltage (12V-15V) and verify the output voltage (5V) 1.2.1. This case study demonstrates how a methodical approach
| Step | Action | Result/Outcome | | :--- | :--- | :--- | | 1 | Replaced the primary side's to resolve a primary side fault. | The fault on the primary side was fixed. | | 2 | After fixing the primary side, the board still had 0V output (secondary side fault). | A secondary side fault was diagnosed. | | 3 | Checked SMD resistors, diodes, and capacitors on the secondary side; all seemed OK. | Some components did not have any reading, suggesting potential missing or faulty SMD capacitors . |
Disclaimer: Repairing electronics involves high-voltage risks. Ensure the device is unplugged before touching components. If you can tell me: Your contribution might be exactly what another technician
; use a multimeter to check voltage stability at the output connectors. Troubleshooting Steps Visual Inspection
: Fast-acting transistors pulse the primary DC voltage at high frequencies into the main power transformer.
The power supply was completely dead, with no output voltage. When connected to a 220V mains supply, the primary side of the board was receiving the correct high voltage after initial repairs, but the secondary side remained at 0V, indicating a fault in the primary-side switching circuit or the secondary-side regulation components .