| Symptom | Most Likely Cause | Solution | |---------|------------------|----------| | Device not recognized by USB | Damaged CH340G during soldering | Replace CH340G; check D+/D- traces | | Reads random data (0xFF or 0x00) | Bad crystal or clock | Re-solder crystal caps; check for solder bridges | | Vpp never reaches 12V | Blown transistor on charge pump | Replace Q1 (usually 2N3904 or S8050) | | Overheating after 2 minutes | Short in power mod circuit | Check for solder balls under MP1584 module | | Firmware flash fails | Wrong bootloader configuration | Use Pickit3 in "Low Voltage Programming" mode |
Once reworked, the iProg becomes a "Swiss Army knife" for auto repair: Airbag Resets: iprog rework
The original clone uses a linear regulator (often an AMS1117 or similar) that overheats and drops voltage when programming high-current MCUs like the Motorola HC912. | Symptom | Most Likely Cause | Solution