Wannien 101v0 Power Supply Schematic Verified Page

Use a multimeter to check the input fuse for continuity. If it's blown, it usually indicates a failure elsewhere in the circuit (like a shorted transistor).

: Check the main fuse (F1) and the bulk 400V capacitor. If the fuse is blown, the bridge rectifier or the main MOSFET (Q1) is likely shorted. Flashing Power LED

Electrolytic capacitors filter incoming noise and stabilize voltage. B. Regulation Stage (5V Output)

can be requested through platforms like JustAnswer , where experts can provide specific component values for repair.

https://github.com/johnelectron/smps_schematics/blob/main/Wannien_101V0_revA.pdf wannien 101v0 power supply schematic verified

The filtered AC enters a bridge rectifier assembly, transforming it into high-voltage DC.

. If the voltage is abnormal, inspect the feedback loop and the reference voltage of the control IC (often around 12V). Connector Check:

If you cannot find the exact component, compare the schematic with standard 12V-to-5V regulator circuits to identify compatible replacements.

A medium-power transistor (such as a TIP41C or BD139) amplifies the small correction signal from the op-amps. Use a multimeter to check the input fuse for continuity

A voltage regulator or PWM controller to maintain stable output.

Often paired with switch boards like the CNKD0401-14004A3 . Verified Troubleshooting & Circuit Sections

| Symptom | Likely failure (from schematic) | Test point | |-----------------------------|-----------------------------------------------------|------------------------------------| | No output, fuse intact | Startup resistor open, or IC1 dead | Voltage at IC1 pin 7 (should rise) | | Output voltage jumps / unstable | TL431 divider resistors drifted, optocoupler weak | Output divider junction (~2.5V) | | Output low (e.g., 8V instead of 12V) | Secondary filter capacitor high ESR, or feedback loop broken | Check C2, C3 with ESR meter | | Squealing noise + no output | Transformer shorted turns, or output short circuit | Resistance across secondary winding | | Blows fuse immediately | Bridge rectifier shorted, MOSFET shorted D‑S, bulk capacitor shorted | Diode test on D1–D4, MOSFET |

| Criterion | Done? | |-----------------------------------------------------------|-------| | Main IC type identified and matched to datasheet | ☐ | | Startup circuit matches typical application | ☐ | | Feedback loop (TL431 + optocoupler) pinout correct | ☐ | | Transformer primary/secondary/aux pins correctly mapped | ☐ | | Output voltage calculated from divider matches label | ☐ | | At least two independent sources agree | ☐ | | Your own physical board follows the schematic exactly | ☐ | If the fuse is blown, the bridge rectifier

The bulk filtering section consists of large aluminum electrolytic smoothing capacitors (typically two 4700µF or 6800µF capacitors rated at 50V). If your unit has an underlying hum or drops voltage drastically under load, these capacitors are prime suspects. 3. The Control and Error Amplification Loop

This regulator is the core of the 5V rail. If the monitor shows no signs of life, the output of this regulator is the first point of failure. C. Transistor Switch Circuits

on Elektrotanya, as many Wan Nien boards share similar designs with FSP-group power supplies. Are you dealing with a specific symptom , like a flashing power LED or a completely dead unit?

A shorted Schottky diode on the output or dried-out, bulging output filtering capacitors will trigger the PWM chip's over-current protection (hiccup mode). Optocoupler or TL431

(e.g., PC817) provide isolated feedback to the PWM controller to maintain stable voltage. 3. Inverter Section (Backlight) Controller IC : Commonly a MOSFET Pairs : Two small SOIC-8 or TO-252 transistors (e.g., ) that drive the inverter transformer. Inverter Transformer

The Wannien 101V0 power supply schematic, when verified, serves as an indispensable roadmap for electronics technicians. It confirms the interplay between the primary PWM controller, the switching MOSFET, and the secondary feedback loop. While these boards are relatively simple in design, the lack of official manufacturer documentation means technicians must rely on community-verified reverse-engineered diagrams. Verifying the schematic involves checking the PWM chip model (usually OB2263), the PS_ON transistor logic, and the feedback resistor divider networks. With a verified schematic in hand, repairing the common "no power" or "blinking power LED" symptoms on these units becomes a systematic and solvable process.