Hi all, I've just finished building an ICD and got it hooked up to the PC today to test it out. All seemed to go well until I carried out the self test, here it reported that the Vpp was low. Checking the Voltage update and looking at it with the scope confirmed that it is at 9.7 volts. The only departure from the original spec is the transistor Q3. I could not get a 2N2907A so used a 2N2905A which according to the spec sheets has the same hfe as the 7 but a slightly lower watt rating. Does anyone know what the problem might be here, or where to look? Whilst on the subject of the ICD, this dam LED, is it just supposed to be on or does it do something else. I can see the DRB2 line pulsing on the other side of the 100 ohm resistor when the ICD is not hooked into the PC, but with the 330 ohm resistor from the VDD I cant see how it will ever do anything other than be on! TIA, Philip Martin. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.