In message , D Yuniskis
writes
So, it is not that the power source to the XMAS lights may
have aged. But, have you verified that your current (now dim)
lamps are still seeing the same current? I assume you just used
a fixed resistor in series with each?
Unfortunately 'white' LEDs do dim over time, the phosphors used emit
less and light output goes down even when driven consistently at lower
than maximum ratings. The cheaper the LED, the faster they dim and also
the harder you drive them...
--
Clint Sharp