HTX-404 440 MHz UHF FM Transceiver (190-1140) Error Codes Faxback Doc. # 6178 The HTX-404 has two error code displays. This section explains each error code. ER1: Internal RAM Error ER1 indicates that the HTX-404 has detected an error in its battery-backed up memory. This is most commonly caused by a low lithium backup battery, but can also be caused by static discharge or a physical shock. To clear the error, reset the HTX-404 by turning it off, then holding down F + D while you turn it on again. This clears and reinitializes memory. If the transceiver frequently displays the error have the battery replaced by an authorized RadioShack repair center. ER2: PLL Unlock Error ER2 indicates that the HTX-404's PLL section has unlocked. Have the HTX-404 repaired by an authorized RadioShack repair center. (RLR/EB 3/2/98)