Experimenter board problems

[Kiwi Bruv]

I have just come across a strange one.

I have program which starts off by sounding a buzzer for 5s. It's worked fine for a month. Now when the board is not connected to the PC ie 4.5V battery pack or 9V supply (but not simultaneously!) the program hangs and the buzzer sounds continuously.

On one occasion only I got the board working and then it reverted after about 10s tot he continuous beep.

Is it my picaxe or the board?

If I plug in the PC and switch the board power on it works perfectly!!!

Heeeeeelp!

 

[Technical]

Sounds like there is a fault with the 22k/10k pull down resistor on the serial in line. When the cable is removed the serial in line is not being pulled low correctly, resulting in a hung program.

Check your soldering!

 

[Kiwi Bruv]

Thanks Technical.

I plugged in a 28x from another project and it works fine.

I fried the PWM output on the 18x about 6 mnths ago, so I'm assuming it wasn't just this that was damaged. This might be a lesson, if the chip is damaged bin it.