6
TROUBLESHOOTING
We hope you’ll never get to this step. We all know bad things happen. But do not despair! First,
CYBERMAX FM+
is reverse polarity protected so it should blow a fuse if you reverse polarity. Fuse is the first thing to check. SWR and
TEMP protection should help, too, although you should still be careful not to exceed ratings. Next check your mains
power supply and antenna, make sure they are working properly. Also make sure your coaxial cable leading to the
transmitter is not shorted or open. If you have problems that you cannot solve yourself, please see our website for
contact information and support resources in our forum. Also check troubleshooting table on the next page and report
any other problems/solutions you have encountered so we can add them to the spreadsheet.
Troubleshooting table
PROBLEM DESCRIPTION
POSSIBLE SOLUTIONS
Red LED constantly on
1. High SWR. Check SWR and adjust antenna, if needed
2. PLL is not locked. Remove audio and see if this is caused by audio. If yes,
read below for more ideas.
3. Wait a few seconds. Unit turns this LED on when changing power or
frequency just for a few seconds until VCO stabilizes. This is normal behavior.
Transmitter cutting off with high
audio
Check if this problem goes away when there is no audio. If yes, look into the
MAX PRO 3+ manual and see how to disable PLL unlock. The problem is
either that your audio exceeds max. permitted deviation or the protection is
slightly too sensitive.
Audio too quiet
If this is DSP unit, set left and right channel gain to a higher value.
Audio too quiet
Open the top lid and open modulation trimmer on MAX PRO 3+ board a little
bit.
Audio still too quiet
Look into the MAX PRO 3+ manual, a section there explains how to increase
audio level.
Unit does not lock on frequency
above 102-107MHz
What is your mains power supply voltage? It should be more than 12V (13.8V)
or 15V for maximum power output!
Output power less than expected Is your supply voltage less than 15V? Your output power will be substantially
reduced at 12V!
Output power less than expected If unit is overheating it will start reducing output power, Make sure it is
sufficiently cooled!
Output power less than expected Units can have slightly reduced output power at the band edges around 88 and
108 MHz. You can improve performance by tweaking coils a little bit.