Video summary

¡ANTES DE REPARAR TU GRÁFICA MIRA ESTE VIDEO! CÓMO REVISAR LA TARJETA GRÁFICA PASO A PASO.

Main summary

Key takeaways

Technology

Basic GPU repair — step-by-step overview

A concise summary of a basic graphics‑card repair/troubleshooting course that walks through visual inspection, reading schematics, identifying power circuitry, bench‑powering the card, and measuring voltages and resistances.

What the video covers

  • A step‑by‑step visual walkthrough of diagnosing a GPU PCB.
  • How to use a board schematic (or close revision) to identify power phases, rails and test points.
  • Practical measurements and checks performed with a multimeter and bench power setup.
  • Guidance on when a fault is simple (fuse, shunt) versus when it requires advanced VRM/controller diagnostics.

Key technical concepts and components

  • Use of the board schematic
    • A schematic for a close revision is usually sufficient to identify components, phases, rails and test points even if it’s not the exact revision.
  • Power input path
    • PCI‑Express connector pins 1–3 supply 12 V to the card.
    • The 12 V lines typically include a fuse and zero‑ohm shunts for protection and sensing.
  • Inductors / coils (L1, L2, L12, L13, etc.)
    • Act as output filters for each power phase.
    • Multiple coils in parallel represent multiple phases to increase current capacity.
  • MOSFETs and drivers
    • MOSFETs switch 12 V pulses; gate drivers (integrated driver/IC) control the switching to generate lower voltages.
  • Voltage rails
    • 12 V input (PCIe)
    • Intermediate rails transformed down by the VRM (examples: ~1.5 V for memory/aux, ~0.8 V for GPU core — actual values depend on model).
  • Other ICs
    • Fan controller (referred to as “223” in the transcript)
    • 5 V regulator
    • Main VRM controller / phase management ICs that manage MOSFET switching
  • Component roles
    • Capacitors after inductors smooth the outputs.
    • Fuses and zero‑ohm resistors provide protection and sense points.
    • Memory chips typically on the back of the PCB.

Practical troubleshooting / test steps

  1. Visual inspection
    • Look for burned, cracked or missing components, swollen capacitors, bad solder joints and readable board markings.
  2. Identify board revision and compare to schematic
    • Use the schematic to locate phases, coils, MOSFETs, regulators and test points.
  3. Continuity / resistance checks (multimeter)
    • Measure coil/inductor resistance (from ground or across the coil). Expected ranges:
      • Tens of ohms for some coils.
      • Very low ohms (down to ~1 Ω) for very high‑power GPU phases — low values are normal and can look like a short.
    • Check fuses and zero‑ohm resistors (they should show continuity).
  4. Bench power the card (outside a PC)
    • Use a PCIe test board or jumper the PSU correctly (short PS_ON / green wire to ground to start PSU).
    • Provide the 12 V PCIe connectors from the PSU and measure:
      • 12 V at the PCIe input and coils.
      • Lower VRM outputs (e.g., ~1.5 V, ~0.8 V) at the coil outputs / test points.
    • If expected rails are missing → suspect open fuses/resistors, bad MOSFETs/drivers, or a failed control IC.
  5. Functional test on motherboard
    • If rails are present, test the card on a motherboard to see if it posts/displays. If it fails, investigate GPU core, BIOS, or power‑management ICs.

Common failure points

  • Open fuse or open zero‑ohm resistor on the 12 V path.
  • Faulty MOSFETs or their driver/controller ICs.
  • Power‑management/controller IC shorted or not enabling rails.
  • Faulty enable/enable‑signal (referred to in the transcript as the “propeller enable”) that turns on VRM / fans / rails.

Notes & cautions

Very low resistance on GPU power coils is normal for powerful cards — don’t assume a short without context.

  • If you don’t have the exact schematic, use a close revision as a guide but expect minor differences.
  • Simple checks: visual inspection, fuses, resistances and voltages.
  • Complex faults: controller IC failures and advanced VRM problems may require advanced repair skills and equipment.

Practical checklist

  • Visual inspection
  • Obtain schematic / identify board revision
  • Locate PCIe input, fuses and zero‑ohm shunts
  • Measure coil/inductor resistances and compare with reasonable ranges
  • Bench‑power the card and measure 12 V input and VRM outputs
  • Check MOSFETs, driver ICs, fan/regulator ICs
  • If rails are OK → test on motherboard for image/output
  • If rails missing → check fuses/resistors/MOSFETs/controller ICs for faults

Main speakers / sources

  • Unnamed presenter (video host) — primary source of explanations and walk‑through.
  • Referenced materials: board schematic (example revisions cited: 1.0 vs 1.1) and the GPU PCB / schematic documents used during diagnosis.

Original video