If you have a look on the Resources page and scroll down you will find a subject with the heading 'Slap my slotcar', here is a guarenteed fix for the SCX lights. Had the problem myself with a few of my SCX cars with the lights working,stopping or stuttering and used this fix and they all now work fine. All the parts for the fix can be found on Ebay for a very cheap price. LED's, Diodes and Resistors you can usually pick up in lots of 100 (thats what they were selling them as). For under $10AU I've got enough to fix 100 cars ,but since I only had to fix 4 I've used most of the LEDs and resistors for lighting around my track. As usual pretty much everything you need to know can be found somewhere on this forum.