Wannien 101v0 Power Supply Schematic Free Upd -

If the meter beeps continuously or shows less than 10-20 ohms of resistance, you have a shorted component on that specific voltage rail.

Once components are replaced, clean the board thoroughly with isopropyl alcohol to remove residual flux, which can be conductive at high voltages. To safely test the board without risking another catastrophic component failure, utilize a (a standard 40W–60W incandescent light bulb wired in series with the AC hot line leading to the power supply). When you flip the switch:

The high-frequency transformer provides galvanic isolation and steps down the voltage. The secondary side manages regulation:

Working on switch-mode power supplies carries inherent risks of severe electrical shock.

Protects the downstream circuit from high-voltage spikes and surges by clamping the voltage to safe levels. wannien 101v0 power supply schematic free

Inspect the secondary capacitors for bulging tops. Even if they look flat, test them with an ESR meter. Replace any high-ESR capacitors. Failed Feedback Loop

: Each output is governed by a specific transistor that can be toggled by a trigger circuit.

Always replace secondary filtering capacitors with Low-ESR variants rated for 105°C. Standard capacitors will fail prematurely due to high-frequency stress.

High-current paths around the rectifier and MOSFET can burn away during a short circuit. Reinforce repaired PCB traces with solid copper wire if the trace material has delaminated. If the meter beeps continuously or shows less

: Often the best source for high-quality photos of the board, which can be used for "visual tracing" of the circuit paths. Cautionary Note

⚠️ The primary side of this power supply contains lethal voltages (300V+ DC) that can remain stored in the main filter capacitor long after the device is unplugged. Always discharge the main capacitor using a dedicated discharging tool or a high-wattage resistor before touching the board. Never use a screwdriver to spark-discharge the capacitor, as this can destroy sensitive surface-mount components and damage the board traces. Step 1: Visual Inspection

If the board powers on but the display is dark, the high-voltage transformers in the inverter stage are the primary suspects.

A high-speed Schottky diode rectifies the high-frequency AC output from the transformer. When you flip the switch: The high-frequency transformer

However, do not despair. This article will explain the likely internal architecture of the 101v0, provide a “free” alternative to the official schematic by helping you trace the circuit yourself, and point you to crowd-sourced resources where this elusive diagram has been shared.

If you are reading this, you likely have a dusty Wannien 101v0 bench power supply sitting on your workbench—either non-functional or in the middle of a repair project. Alternatively, you might be a hobbyist looking to reverse-engineer this classic, budget-friendly linear power supply for a custom build.

Use a multimeter to verify stable voltage output before replacing the entire board. Most variants provide standard secondary voltages (typically +5V and +12V). Sourcing & Availability

A set of four diodes that flips the negative cycles of the AC wave into positive pulses.