Home Theater Questions? Ask a Technician for Answers ASAP
Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, please confirm that the description of "...device sleep with 15 sec..." applies only to the HKTS200SUB (subwoofer)
And is this a fresh/new? ...or has it been in use for some time and this issue just recently?
Please try (if have not been done) exercising the POWER ON MODE switch a couple of times and leaving it set to ON position.