I have a Lionel 6-38079 SP daylight and a Santa Fe Legacy B unit .
When the battery is installed, both of these units do not allow a shutdown sequence after the power is shut off and will not sustain power to the sound board whenever there is an interruption.
I have of course changed and checked the battery. I also checked the 9 volts to the plug and under the PC board and it is present. I even bought a power supply board and replaced it but it did not help.
Anyone else had this trouble and found out what caused it.
Thanks, Dave