I have constructed the following circuit on a breadboard and all functions as it should with no issues.
However, each time I solder this project onto a perf board, the same issue arises. The LED starts bright then goes dim upon powering up. Then I get no functionality. It is an cree 3 Watt LED that uses two buttons, a TIP31, a 5V supply and a digispark ATtiny85. The draw is 600 mA maximum as measured when connected to bread board.
What I've done:
- Measured 5V at input pins from buttons. Both check.
- Reprogrammed the ATtiny after assembly.
- Checked continuity on perf board to input output pins and power.
- Power the LED directly, works fine.
Perhaps the digispark is that sensitive to solder heat? The transistor is a bad selection?