4Trouble shooting
There is no output signal
•ensure that the green power LED on the front of the card is lit
If not:
•check the resettable fuses protecting the card - do this by removing the power
to the card for about 30 seconds then restore the power
•check the PSU indicators to confirm that there is power to the frame
•check that the inputs are connected to the rear panel and valid signals are
present
•check that the red Invalid LED is not lit for either sub-module
•check that the red Loss of I/P is not lit for either sub-module
Notes:
he card edge green power LED will only illuminate if all voltage rails regulated on
the module are present.
he Invalid LED will light if the Validity bit in the input bit-stream has been set to 1,
to indicate that the associated sample is not suitable for conversion. his could
occur if other than a linear PCM digital signal, such as Dolby AC3, were ever input
to the card.
The output signal is corrupted
•check the quality of the input signal
•check that the appropriate terminations have been set
•check that a green sample rate LED is lit and is appropriate for each sub-module
input
The output signal has pops and clicks sometimes
•check for a valid common reference for all digital audio source or processing
equipment in the system
Note: It is recommended to employ a common station video reference or a common
AES11 reference for all digital audio equipment if accurate phasing to station signals
is required throughout a facility.
8Issue 1
Audio Digital to Analogue onverter
