Use a for low-voltage chips (e.g., modern laptop BIOS).
Practical tips
| Problem | Likely Cause | Solution | |---------|--------------|----------| | “Chip not found” | Wrong voltage or bad connection | Set 3.3V; reseat clip; check pin 1 | | Read returns all FF | Chip empty or not contacted | Lower SPI clock to 100 kHz | | Write fails at 0% | Write-protect pin held high | Check WP# pin – pull low (or use 3.3V) | | Verify mismatch | Buffer vs chip diff | Re-read, re-write, or chip may be dying | | Programmer not detected | Driver missing | Install CH341A driver via Zadig (WinUSB) | siberiaprog ch341a full