GTX 1660 Super Resistance Values – Complete Diagnosis Guide
The NVIDIA GTX 1660 Super is one of the most commonly repaired mid-range GPUs. While generally reliable, these cards often develop faults related to power rails, short circuits, and VRM instability.
One of the fastest and safest ways to diagnose these issues is by measuring resistance across key rails. This guide provides real baseline values and explains how to interpret them in practical repair scenarios.
⚡ Why Resistance Testing Matters
- Detect short circuits before powering the GPU
- Identify faulty MOSFETs and capacitors
- Prevent further damage to GPU core or memory
- Quickly isolate faulty power rails
📊 GTX 1660 Super Resistance Values
| Power Rail | Typical Resistance |
|---|---|
| VCore | ~0.8Ω |
| VMem | ~27.5Ω |
| PEX | ~15.1Ω |
| 5V Rail | ~10.5KΩ |
| 1.8V Rail | ~4.1KΩ |
| 3.3V Rail | ~95KΩ |
| 12V (PCI Slot) | ~2MΩ+ |
| 12V (8-Pin) | ~636KΩ |
🔍 How to Measure Resistance
- Ensure GPU is completely powered OFF
- Set multimeter to resistance (Ω)
- Black probe → Ground
- Red probe → Inductor or rail point
- Record readings and compare
🧠 Interpreting the Values
VCore (~0.8Ω)
Very low resistance is normal. Near 0Ω usually indicates a shorted MOSFET or GPU core.
VMem (~27Ω)
Low resistance suggests possible VRAM or memory rail issue.
PEX (~15Ω)
Abnormal values can prevent GPU detection by the motherboard.
1.8V & 5V Rails
Should be in kilo-ohms range. Low resistance indicates regulator or capacitor fault.
3.3V & 12V Rails
Should show high resistance. Any drop indicates a strong short.
🛠️ Common Fault Scenarios
Dead GPU (No Power)
- Low resistance on 12V rail
- Likely shorted MOSFET
No Display
- Check VCore and PEX rails
- Verify VRM enable signals
PSU Shutdown
- Short on 12V rail
- Immediate protection trigger
Random Crashes
- Weak MOSFET or degraded VRAM
🔬 Real Technician Insight
Most GTX 1660 Super failures are not direct core shorts. In many real cases, the issue comes from weak VRM phases or degraded capacitors rather than completely blown MOSFETs.
⚠️ Important Notes
- Values may vary by manufacturer
- Always compare with a working board
- Never power ON a card with a suspected short
✅ Conclusion
Resistance testing is a critical first step in GPU repair. Using these baseline values, you can quickly identify faults and avoid unnecessary component replacement.