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Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, there is a partial test to confirm if the remotes (original and universal) are working or not. With fresh batteries correctly installed, point the remote towards the lens of an active digital camera. For every press of any/all button(s) on the remote, there should be a bright light that would register on the LCD screen of the camera.
No light, no infrared transmission from the remote; remote most likely faulty.
On the otherhand, if the remote is good, then consider a possible IR sensor hardware concern in the unit itself or a compatibility issue.
Please post back results of camera test.
Based on the results of "...Remotes are good...", then it would be an internal hardware issue.
Are you then considering a DIY (do-it-yourself) repair approach? If yes, do you have access to and familiar with a multi-meter and even a soldering iron?
Offhand, primary checks on likely suspects would be on:
Please post back how you would want to approach this and/or should additional information be needed.