Mag LT776s noise from speakers when off

[oktools]

Hello,

I have a strange issue with my monitor. The speakers emit a very high pitch whine/squeal when the monitor is off. This happens when everything is connected, or when everything is disconnected(other than power input).

This monitor is over ten years old and has just started to do this. I opened it up thinking it may be the inverter board and disconnected the board and the noise was still there.

This model uses an external power brick as a power supply, so I then thought maybe it was going bad and allowing current through. I purchased a new power supply and plugged it in and the noise was still there.

I plan on replacing some capacitors on the logic board. Does this seem like a valid route to go, or would it be very unlikely that this is caused by a bad capacitors on the board? Su'scon S5 series Caps(I do not know if these are low esr or not).

[selldoor]

Re: Mag LT776s noise from speakers when off

If you are saying the sound is only there when only the board with the speaker socket on is connected to the power supply then you really only need to look at that board.

After the noise is sorted you may want to replace all the caps to prolong its life.
BUT may not be worth it as the bulbs may be on their way out.