Dual card dual standby can only be the one how is it?

Users questions: My phone is dual sim dual standby, and spent more than a year, now only two-card single question, but the two cards can switch between each other without changing position, the other functions are normal. Dual card is useless to open, and I tried N times, the signal did not open, is it broken?
Experts answer: is the phone hardware itself asked Problem, the machine did not handle aging dual standby mode! Just as people young and old, the same can look like you have two baggage
  • This information provided by the users.Thanks!