FS-4DA coin sorter won't count pennies
The good news is that the unit is functioning, it's just counting pennies. I had the same problem with quarters and is a fairly easy fix. I won't get into any disassembly details, but you'll need to gain access to the infrared detectors (mounted to the motor assembly) and possibly the emitters (mounted to the front panel LCD display/push button board). Also, please be careful not the damage the wire harnesses when removing the top cover. Once apart, you can use your cell phone camera (which is sensitive to infrared) to see a purplish/white glow from a healthy emitter. Compare the penny emitter to the others and chances are it will have a lower output level and need replacing. If the penny emitter is strong, then check the detector with any infrared remote control( TV, cable box...) by pointing the IR remote control towards the penny detector and pushing any of its control buttons. This should make the penny amount count up, and fast too, as the remote sends out IR pulses while a button is being pushed. If this test doesn't increment the penny count, then the penny detector needs replacing. But before you do, try this remote control test on another known good detector to verify your findings. Please keep in mind that other malfunctions besides an emitter and detector could be the cause of your problem, but given the FS-4DA circuitry, the odds are extremely high that you have a bad emitter 1st, then a detector 2nd, as emitters are known to degrade over time and especially when continuously powered, as in the case of a switched 'ON' FS-4DA. FYI...IR emitters and detectors can be purchased from Radio Shack. Good luck and take care not to electrocute yourself when powering the unit with its cover removed.