ZETRON Model 25, Product Manual, Page: 69 / 147

Troubleshooting
025-9567E 61
Fault Possible Cause
Channel busy indicators
apparently out of control. Channel busy input floating at high impedance (check jumpers
on Encoder Bd.).
Channel busy input not connected properly.
Front Panel Bd. channel busy circuit faulty.
Encoder Bd. display driver faulty (U8, J2, U19).
Cable between Encoder and Front Panel boards bad.
Channel busy not detected or
always detected busy. Encoder Bd. channel busy circuit bad (JP7-JP10 , P3, P5).
Encoder Bd. channel busy detector bad (, U19).
Programming not performed properly.
Instant call panels not
recognized but not indicating
loop error. RMT-CTL signal at computer port is at wrong level.
Encoder Bd. not detecting RMT-CTL pin properly (J4, U26, U29,
U21,).
Computer Port cable bad.
Serial port turned off via installation aid.
Loop error previously occurred but was never corrected.
Loop error, "Err0", intermittent
or persistent. Intermittent Instant Call panel loop connection(s).
Auxiliary Panel interconnections too long.
Intermittent electronics on Instant Call panels.
Encoder Bd. loop circuit bad (C49, C50, Y1, U19, U30, U21,
U26, U29, U28, U27, P4, J4).
A device attached to the Computer Port connector is driving the
RX data signal.
Characters received on the
Computer Port cause the
encoder to beep or behave
unexpectedly. Serial device baud rate does not match programmed encoder
baud
rate.
Serial device is not sending 8 bits with no parity.
Computer Port RMT-CTL signal at wrong level (not in remote
control).
Serial Port turned off via installation aid.
Loop error previously occurred but was never corrected.
Digital Bd. crystal oscillator off frequency.
Serial device cable too long.
Key shorted on Front Panel Bd.
Encoder Bd. serial port bad (U26-U30, U21, J4).
Cannot reset the encoder using
a break level on the Computer
Port RX data signal, or encoder
sometimes resets when it
receives characters from the
Computer Port. Serial device bad.
Encoder Bd. break detect circuit bad (U26-U28).
Encoder apparently not
sending call status out from the
Computer Port. Serial device bad.
Serial device cable bad.
Computer Port connector cable bad.
Call logging turned off.
Serial port turned off via installation aids.
Serial Device baud rate does not match programmed encoder
baud
rate.
Encoder Bd. crystal oscillator bad.
Encoder Bd. serial port bad (U30, U29, U21).
Call logging disabled.