Sporadic transformer vibration issues- Hitachi DA 1000R

[maca verde]

Hi, I have a second gen Hitachi DA 1000R (the one with the silver power button). I love its 80s styling and cheery if slow opening and closing mechanism.

It however has a vibrating transformer which causes the CD to not play while it vibrates. I can imagine the oscillations making it very difficult for the sensor to read the reflected laser light so no surprises there. What is strange is that it does not always vibrate, in fact it is infrequent, but when it does happen it happens for a several hours. If I then power it up a day later it can be fine for a few days. Not being able to consistently reproduce a fault can be very frustrating.

My question is, could it be possible that something else external is causing the transformer to vibrate? And if so could a mains conditioner make a difference? The other devices I have plugged in near it are a quad 33 preamp, meridian m2 active speakers and a small micro ITX computer with a pico power supply. I will need to wait till its next vibrating session to do some more troubleshoot turning off other devices.

Before I do anything drastic like dunking the transformer in some epoxy resin I want to be sure that the problem isn't external (or something else internal). Looking inside (as best one can with such a cluttered collection of boards) there are no visibly dying capacitors.

Any advice would be greatly appreciated. Thank you.

 

[DaveVoorhis]

Hi, I have a second gen Hitachi DA 1000R (the one with the silver power button). I love its 80s styling and cheery if slow opening and closing mechanism.

It however has a vibrating transformer which causes the CD to not play while it vibrates. I can imagine the oscillations making it very difficult for the sensor to read the reflected laser light so no surprises there. What is strange is that it does not always vibrate, in fact it is infrequent, but when it does happen it happens for a several hours. If I then power it up a day later it can be fine for a few days. Not being able to consistently reproduce a fault can be very frustrating.

My question is, could it be possible that something else external is causing the transformer to vibrate? And if so could a mains conditioner make a difference? The other devices I have plugged in near it are a quad 33 preamp, meridian m2 active speakers and a small micro ITX computer with a pico power supply. I will need to wait till its next vibrating session to do some more troubleshoot turning off other devices.

Before I do anything drastic like dunking the transformer in some epoxy resin I want to be sure that the problem isn't external (or something else internal). Looking inside (as best one can with such a cluttered collection of boards) there are no visibly dying capacitors.

In advice would be greatly appreciated. Thank you.

Does the transformer have screws either holding it down, or holding its case halves?

If so, try tightening them.

It's unlikely that the vibrations are due to external power problems. They're more likely either an internal short in the unit causing an unusually high load -- that can make a transformer hum -- or mechanical looseness. Unfortunately, windings can come loose internally and cause vibration.

I've heard tell of poor quality switch-mode power supplies distorting the line supply enough to cause problems with nearby linear supplies, but I've never seen it and I'd expect it to only occur with a really beefy switch-mode supply. Might be worth unplugging the ITX computer and other nearby appliances whilst you run the unit just to check, though.