electrician advive needed re lighting..are you there LeckieCJ

titewad_2

I posted a while back about changing a light fitting and the wires not fitting into my new light.LeckieCJ kindly advised on using a junction box in the loft.
Today I have attempted this but for some reason one of the lights won't work.There are two lights on the landing,both work off the same switch.The first light I changed several weeks ago and it worked fine.After using LeckieCJ's advice,the problem light which I did today works but the first one doesn't.I have checked the bulb and used a known good one.
I am guessing I'm putting a wire wrong somewhere so can someone help please.
My new light fittings are double earthed so only using live and neutral and not havin been rewired recently,my wiring is still red and black.
The problem light has two red wires each three cores.It then has four black wires,three of which are 3cores the fourth being a single slightly thicker core.
Connecting all the blacks together ,it works but the other light doesnt,same if i omit the single core black and still the same if I stike the single core against the red (a poster on my original thread said that one black was permanently live)
I know most peoples advice will be get a pro in but at £25 an hour i cant afford it as I have been off work sick for a month with my arm in a sling.

24_hour_sparks

lol, sorry but if your not sure exactly what your doing my advise would be dont touch it in the first place.
to late now but i good idea i tell people who phone me up asking for a cheep job is to take a picture on your mobile or your digi camerea and if it goes wrong you have a diy way of getting it wired corectly.
recomend to call a registered electrician.