Technics SX-PX224 digital piano

subspace · Joined: 12 Jul 2010 Posts: 3

I have acquired a Technics SX-PX224 digital piano which has a power-up fault. Essentially when it is switched on the LCD display and all the mode selection buttons are dead and it doesn't make a sound. However, there is a small red power LED which lights-up.

I have checked for loose connectors, blown fuses and any obvious signs of damage. I was checking some of the pins for voltages and was able to find +/- 15V but not 5V although I did find lots of pins at 1.3V. I found one pin labeled +5D but the voltage on it was only 1.3V.

Does anyone have a service manual for this piano?

Pentode · Joined: 30 Oct 2007 Posts: 85 Location: Nr. Manchester (UK)

We need to trace that voltage back to source, usually a regulator... I had something like this in a digital piano but it wasn't a Technics.

I found two chips pulling the 5V rail down... I advised to return it to the makers as these were customized chips - not readily available,. To find the fault I cut the supply track to various chips, luckily the 2nd cut proved there was a very low reading between the chip supply and ground, so I cut the supply track to it's mate and that chip was the same....

I called it a day suspecting some that someone had used the wrong power adapter, used too much voltage or connected it up wrong.

But DO start by tracing the 1.3 V back to source and start there, it may be just a faulty regulator... and it may well should be 1.3V

Dave

subspace · Joined: 12 Jul 2010 Posts: 3

There also seems to be some sticky orange "goo" around one of the larger capacitors. I think it is adhesive but can capacitors "leak" in this way?

subspace · Joined: 12 Jul 2010 Posts: 3

I should point out that the capacitor is not bulging or anything.

Kerrybeth · Guest

I have a technics sxpx224 with the same problem. I found a repairman to come and look at it and was told that the main board would need to be replaced at the cost of $900. So, now I have this beautiful piano that is of no use. :0(

kerrybeth · Guest

If there is anyone in the Morgantown WV area that could work on this piano or possibly give a second opinion, I would greatly appreciate it.

Hoelly · Joined: 03 Nov 2016 Posts: 1

hi subspace,
do you still have this piano?
I bought one a few days ago and it had the same errors, after 4 hours searching I was able to find the reason and now it works. Do you need some hints? Can I help?