Some installers may encounter strange Faults for Communication Fail for Receiver 3 or Receiver 4 while they do not have Receiver 3 or Receiver in the system.
![](https://s3.amazonaws.com/cdn.freshdesk.com/data/helpdesk/attachments/production/35037551359/original/X_wdHJRSQUW_TF_i2pgwS5LIE0dXQTjTXA.png?1551658911)
Please follow below steps to trouble shoot these faults:
(1) check the Transmission Format for Receiver 3 (Location: 1450) and Receiver 4 (Location: 1490) and make sure they are “0 – Not used”;
(2) if you install IP module (B426-M) or 3G GPRS module (B450-M + B443) in the system, please check the IP module or 3G GPRS module and make sure the Jumper is NOT on MODE – you should not see the BLUE led;
![](https://s3.amazonaws.com/cdn.freshdesk.com/data/helpdesk/attachments/production/35037552423/original/FYY6hWpJZZRyb6dHu-bNxMF1lLTkGT-txQ.png?1551661254)
![](https://s3.amazonaws.com/cdn.freshdesk.com/data/helpdesk/attachments/production/35037552077/original/OcAxgyrUOid3Q4DO5nh-JBquvxNznhh-9A.png?1551660490)
(3) if you only have one IP module, please do not enable cloud connection for IP module 2 – location 82 and location 7456.
After that, please do arm/disarm to configure the panel. Or you may need to do a power cycle on your panel.