[Elecraft] KX1 has LED switching noise

[Paul Signorelli]

My old 2003 KX1 has low level LED/CPU switching noise.
The switching noise frequency is lower on L1 and higher (and amplitude higher)  on L6 (Brightest Level #6).
L4 is about 80 Hz.
Maybe the aluminum bypass (C10, C12) capacitors are opening up.
i hear it on all bands (I have an 80, 40, 30, 20 meter KX1) and at any battery voltage.
Anyone solve this issue?
Paul  w0rw