Voice recorder for blind persons Milestone 311 - Whistle in the speaker

[corrize]

Hello, I have 2 voice recorder to repair. Same issue : whistle in the speaker, but the sound is good with the headphones (via jack audio plug).
Built in year 2000, I guess that could be the (yellows) capacitors ? What do you thing about that please ?

(I found the specs : tantalum-polymer capacitors 100uF 10v 10%.)

[stj]

whistle while recording or playing back?
lower left under the card socket looks *interesting*
maybe remove the card socket and clean the pcb

[CapLeaker]

I think that problem is different. Check the speaker itself and then follow the traces.

[corrize]

Yes I just saw that on picture : lower left under the card socket seems could be a solder bridge with wire, but it’s only flux and dust because I desoldered the card socket (plastic stuck inside).
I need to check one speaker state because it make a bad noise but I have 2 devices, twice make the same Whistle and it is electronic : I heard it in speakers and headphones (I restested, sorry). It is permanent, it is present in audio menus for navigate, when reading mp3 files, etc. This whistle in constant when I turn the volume up and down.
But the whistle frequency variate a little when the devices goes on : the frequency could up to x2.
With 25 years old, I guess that could be capacitor. But I wouldn't want to discriminate against a component community. I will remove (desolder) the speaker for test…

[CapLeaker]

There is a whistling sound during playback and menu functions. It doesn’t change with the volume and stays constant? It does sound good through the headphones but not through the speakers?

[stj]

could be a cap- does it use any buck or boost type power circuits?

[corrize]

Yes but we can forget the speaker now, I desoldered it (2 wires) for 2 devices, and the same. Same whistle in the headphones. The whistle frequency change a little when I push on buttons.
These devices are too small and simple to have ground issues, I assume the problem is more likely a frequency filtering component that has changed its value. Because both devices have the same problem and are the same age: 25 years.
I could try to replace yellows tentalum capacitors by black ones (if I have) ? Or better ones ?