Little dot MKIII noise issue

[lionel6199]

Hello,
I do have a little dot MKII that I use as a preamp and also as a headphone amp.

While I was listening music couple of days ago a noise appeared sudently.

https://drive.google.com/file/d/1_081b3871hIzzFBtcP5EXhZjlpUth_b_/view?usp=drive_link

The noise can be hear on the speaker from the Jack output as well as on headphones even if there is no input to the amplifier. By turning the volume to the maximum of the MKIII this noise seems to get lower but it is still present. The amplifier still amplify the music as expected. There is just this noise on top of it.

The noise is aroud 100HZ what could indicate that it may be realted to the power supply module?

Would anyone have an input of what could be the cause of the issue and how to fix it?
Thank you for your help

 

[AnalogSteph]

While I was listening music couple of days ago a noise appeared sudently.
https://drive.google.com/file/d/1_081b3871hIzzFBtcP5EXhZjlpUth_b_/view?usp=drive_link

Access denied. If you want everyone and their dog to listen to it you'll need to set permissions accordingly.

The noise is aroud 100HZ what could indicate that it may be realted to the power supply module?

Most probably, yes.

Would anyone have an input of what could be the cause of the issue and how to fix it?

I would start looking for bulging / leaking electrolytics first (even if capacitor quality ought to be good in these). Also make sure none of the rectifier diodes are open or shorted by investigating with the diode test. (A shorted diode makes a good filter capacitor killer.) If there is nothing obvious to be seen, AC measurement of supply voltages may provide some clues.

 

[wwenze]

A shorted diode would blow the fuse.

 

[lionel6199]

Access denied. If you want everyone and their dog to listen to it you'll need to set permissions accordingly.

Most probably, yes.

I would start looking for bulging / leaking electrolytics first (even if capacitor quality ought to be good in these). Also make sure none of the rectifier diodes are open or shorted by investigating with the diode test. (A shorted diode makes a good filter capacitor killer.) If there is nothing obvious to be seen, AC measurement of supply voltages may provide some clues.

I have changed the permission to access the video, sorry for that. I will check the capacitors and the diodes and let you know what I will find. Thanks for your help.