i had the thing working fine - changed the LED’s out for some led strips and found (after a while of trying to figure out why it wasn’t lighting up at all) it drew to much power using all four led slots. shunted led 4 and lit back up… but now it’s a constant on and no sound sensing… it’s possible that while testing / troubleshooting it i shorted something weird for a second.
any idea on how i can find out why it’s not doing the flashy bit to sound and is now just on constantly… the pot is set about midway.
You’ve destroyed the output transistor. Replacing it will most likely cure the problem.
that’s the bc557?
can i replace it with a MPS2222A or 2N3906?
is this the piece that’s limiting how much draw i get into the LEDs?
Yes, BC557
MPS2222A is an NPN transistor, so it is not compatible.
Check the net for compatible types. Mind the pinout and max. current.
replaced it with a pn2907 (276-2023) which says it’s the radio shack equivilant of the bc557b
still constant on… any ideas?
so it turned out to be a bad bc547b
replaced that
but now the power out put to the leds is poor poor poor - not nearly any where near as bright