I had planned to put them up this afternoon as the temperature was around 0°C. (It's been in the minus Celsius region for at least a week now. The local rivers and streams have ice on them — this usually doesn't occur until January, if at all.) However of the 4 100-mini-light strings I have only one lit up. Now, am I going to spend hours testing 300 little bulbs in order to find out the two or three bad ones per string or am I going to go out a buy some replacements? Tomorrow I will have to look for a mini-light tester doodad.