Graphics Card Repair VRM Shorts and Issues

(Under development)


Resolving VRM shorts is a classic area of graphics card repair. In the simplest cases, it might involve identifying and replacing a single failing MOSFET. In other cases, there can be challenging secondary issues like other shorts and possibly extensive PCB damage caused by burned components. There are also cases where there is a VRM issue, but not a dead short. An example of this might be where there is a single faulty (but not shorted) phase, resulting in VRM efficiency issues (excess heat) and instability.

TODO Add VRM sketch

Symptoms Of VRM related Issues

  • Shorts on any 12v rail (most typical)
  • Performance and reliability issues (crashing under load, low VRM efficiency, excessive heat from VRM area)
  • Visual defects in the VRM MOSFETs (bubble on top, dark spots, dimples, solder ball between pins, cracks, burns) TODO show examples


Essential (for simple cases)

  • Multimeter
  • Hot air station
  • Flux, Solder, Kapton tape or foil to protect sensitive components

Very Useful (for advanced cases)

  • PCB preheater (components sometimes require high heat to remove them, heating from underneath can help a lot and may reduce the chances of other components getting damaged by excessive heat)
  • Bench power supply (sometimes it isn’t a case of just replacing a shorted MOSFET, some fixes require deeper tracing to detect other problems e.g. shorted capacitor)
  • ESR Meter (these can be very useful in identifying the shorted phase)
  • Dremel (sometimes components can be seized to the PCB, in these cases, it is safer to Dremel the component away rather than persist with heat)


1. How to detect,

2. How to identify the failing component,

3. How to remove,

Protect nearby capacitors and inductors from heat damage.

4. Testing short resolution,

5. Replacement,

6. final testing

Links to example graphics cards with VRM issues