mpc 60 w/ new inverter: still high pitched whine?

as soon as i turn my 60 on i can hear this loud whine physically coming from the sampler itself and i think some of it spills into the internal sampling and output sections. i just got a whole new replacement screen so i dont think it would be the inverter? any guesses? power supply? i dont know the common problems w/ these older 60's yet so im not so sure what to look for.

Sorry but I dont understand. Do you have a new display or a new inverter?

peace

is the inverter..... it's not on the display is on the chassis...

one think u can try is to isolate the inverter.... recently i change the inverter and that noise was still there... so i try to isolate the new inverter putting on a plastic piece i glue on the chassis... no more pitched whine

high pitched whine is either the invertor or backlight foil vibrating

All inverters make some kind of whine -- some are more audible than others, like Manilla suggested you may need to check for whatever is resonating.

with my 3000 LE, i had both noise inverter and backlight.

For the backlight, i have put somehting behind the el foil and it solved the problem.

Remain the inverter, it's really not a loud sound, but as it is high frequencies, it brings headache at last.

Check to see your SCSI isnt causing the noise, my zip disk adds to this.

I replaced my backlight, and havn't heard it since.
Bright blue now.



EDIT:

I think a broken down backlight causes the inverter undue resistance (as the supply is being limited by the backlights lack of illumination draw).

so it runs at a incorrect power level, thus the noise.

I just noticed that if I boot with the SCSI zip on, and have the is sear h for SCSI and lock up... When I go to sample... The whine is there hard core. If I boot with the zip powered off, and manually activate the zip, none. Was it your scsi?

i dunno. the backlight is brand new and i dont have the scsi option.

Any progress solving the high pitch whine issue? I just got a 60 II off of ebay with scsi option... New backlight... Replaced inverter. As soon as I got it and hooked it up it was making that same horrible high pitched sound. Coming straight from the physical machine. FedEx really roughed up this package and caused a wire attached to the contrast knob to come loose which made the screen blank. I re-attached the wire and got the screen back but the high pitch whine is still there.

If you have the tin can style inverter you can try adding solder to the RF shield solder joints to keep it from resonating.

Some people have had success wrapping the inverter in electrical tape to dampen the resonance.

Also make sure the LCD and EL foil are securely screwed down -- if they are able to vibrate they will make noise.

I recently changed the display foil and also the inverter to get rid
off the whine, but actually, it didn't change much.

I realized that most of the noise is coming from the foil itself,
so I'll try to damp the EL-foil next.

Anyyway, if someone is not sure about the technical specs of the foil,
inverter and their connection, PM me.


TSR

When you open it up and turn it on, can you pinpoint were its coming from? My guess its your power supply or possibly your floppy drive, if its nothing to do w/ ur backlight or inverter.

here was the inverter, even after i change it
so i realize it was that, i put a sort of isolation under the inverter , so it doens't have any contact with the chassis... after that the buzz goes away...

I investigated the buzzy EL problem again. First, I pushed some paper between the EL-foil
and the back of the display chassis, which helped a bit. Next, i installed a big rubber
stripe between the two sockets where the inverter is originally installed with the two screws.
I then attached the inverter on top of that rubber bridge, so that the inverter has no direct
contact with the chassis. The sound did not totally vanish - if you carefully listen.
But, it isn't getting on my nerves anymore!

Summing up, these modifications are a success.

By the way, the inverter that I ordered as a replacement is actually louder than the original,
although it is totally drowned in raisin.


TSR