1. Make sure you're using correct firmware:
- For U.S. BINs = JCOP ENGLISH (JCOP EN)
- For EU/Portugal = JCOP PT
- For Russian cards = JCOP RU
- Avoid JCOP 21, 22 unless verified
2. Check your OmniKey model:
- OmniKey 5321 / 5325 best for EMV work
- Use official drivers from https://www.hidglobal.com/
- Never mix readers between sessions
3. Try different card writing software:
- ATR Tool
- MagStripe Studio
- Proxmark3 (for reading only)
- JCOP Scripting Tool
- CardPeek (best for diagnostics)
4. Test with known-good dump:
- BIN: 4218 83XX XXXX XXXX (Chase Visa Platinum)
- Track1/Track2 format:
Track1: B421883XXXXXXX^SMITH/JOHN^2601101123456789?
Track2: ;421883XXXXXXX=2601101123456789?
5. Use ISO-A mode when writing:
- ISO-A works better with POS terminals
- ISO-B sometimes fails with newer systems
6. Try re-selecting the card in software:
- Close ATR Tool / MagStripe Studio
- Re-open and re-read card
- Sometimes takes multiple tries
7. Test with blank card first:
- Write test data to blank PVC card
- Read it back through OmniKey
- If no data appears → your software has issues
8. Update firmware:
- Use `jcop41y` or `jcop41u` if supported
- Avoid outdated `jcop31`, `jcop31v2`
9. Rotate proxy ↔ IP ↔ ZIP ↔ BIN country match:
- Must be residential USA best
- Always clear localStorage before login
10. If everything else fails:
- Try another chip (some are dead-on-arrival)
- Use different reader (e.g., SCM Microsystems)
- Buy ready-to-use JCOP EN dumps from trusted sellers