MK128 Kitchen Timer Kit

I purchased this kit for my son & he soldered all the components following the instructions. When the batteries were inserted, all the LEDs lit up and stayed alight. Holding the switch down for a couple of seconds produced a descending beep and LD7 went off. The other LEDs remained on. Pressing the switch a number of times caused LEDs to begin to dim, some getting progressively dim with each click. I’ve checked his soldering, which is fine with no shorts. I’ve checked the component positions and orientations (including the PIC) - all are fine. A meter shows 4.59V between pins 1 and 14 of the PIC.
We’re a bit stuck, now. Is it possible that there is heat damage to the PIC - although he was careful soldering!


Mark Owen

Most likely, all leds have been mounted inverted.

Thanks for that, the timer is now working fine. The LEDs were, indeed, the wrong way round! How did I miss it?!! I think both he & I saw the silk screen as indicating the LED anode rather than the cathode. The instructions do clearly show the correct orientation. Ah well . . thanks again. :slight_smile: