topic Re: CMT S20B Hi-fi buttons in Hi-fi Systems

CMT S20B Hi-fi buttons

echase — Sat, 30 Dec 2017 18:03:09 GMT

None of the buttons on my unit work including power on/off. But everything works using the remote control. The display is OK

I tried a factory reset but this needs the EQ button, which of course is one of those not working. Any ideas of a fix please? Don’t think it’s under warranty. How long is the UK warranty?

If it had an eject button on remote I could change the CD but can’t as only the main unit has an eject button. Are there any universal remotes that could eject it?

Nearest answer to this problem I could find online was for a Sony car radio that had its buttons stuck in, but that is not the issue here as I am an electronic engineer and checked that the buttons are giving the right signals to the processor that reads them. It’s puzzling though why the processor is not reacting to the buttons when it performs its other functions, like reading the remote, OK. That is why I suspect it needs a reset.

It should be possible to trick the CD sled motor into performing an eject but would need an external battery, switch and protection diodes.

Re: CMT S20B Hi-fi buttons

Anonymous — Sat, 30 Dec 2017 19:34:55 GMT

Hi there,

Try contacting support on this one. Here is the link for you: http://bit.ly/1Yo3R6C

Let us know how you get on.

Best wishes,

Re: CMT S20B Hi-fi buttons

echase — Sat, 06 Jan 2018 11:47:02 GMT

Their reply included “please note that if this device fails after the 12 months warranty period, the device is irreparable, as the cost of a repair would approach the price of a new unit, hence, the best alternative is to purchase a new set from your point of sale or any of Sony dealers.”

I replied that why would I buy another Sony when I originally chose Sony as allegedly a better brand than my other similar Goodmans HI-Fi. But that has lasted twice as long with no failure. The two Sony home cinemas units I have had in last 20 years were also unreliable.

I am going to try my fix of driving the sled motor backwards to get eject using an external battery and button. To be bulletproof it really needs a small relay adding (not the diodes I mentioned before) that will cut the feed from the unit to the motor whilst the battery is connected. Otherwise, if both external battery and internal driver chip accidentally act at once there may be more current flowing than the chip can take.