flourecent tube with thorn srs ballast not starting.

[rabu]

Wonder if anyone can help with this issue, we curently have a 35+ year old 6ft t12 Thorn flourecent light with high frequency srs ballast, lately when switching it on it wont work, then if we turn off and on again it comes on right away no problems, Could this be the capacitor on its way out? because when the light is on its fine, as bright as always with no flicker or buzzing just when switching it on it takes 2 attempts.
Should say aswell that after the first attempt of switching on, nothing at all happens no flicker or anything like that, then off and on again with switch and light comes on fine. Any help with this would be welcome as it is a bit irritating. Thanks.

 

[333rocky333]

If its in parralel across the mains then no its not the cause

If the capacitor is in series with the choke then remove it and temporary link out to try it, a faulty one will do what your saying

And its not a high frequency ballast if 35 years old

 

[Spark123]

Are you sure it is high frequency and not just a capacitor start fitting?
Have seen the connections go crispy to the ballast on the latter, just a case of losing the supplied connections and replacing with insulated spade crimps.

edit - SRS = semi resonant start hence it will be the type I am thinking of, with it powered down have a look at the plastic connectors on each end of the ballast. There will probably be some browning on them from heat over time. If you give the wires a gentle tug one of the wires is likely to pull out, better to replace all 4. Use a ratchet crimping tool too.
I should also maybe mention they only work properly with the older fat tubes (T12)

 

[rabu]

thank guys, il have a look tomorow and double check, as mentioned it may just be capacitor start but deffinatly has SRS ballast, and yeah if it needs rewiring then thats no problem, and yeah know about the tubes only working if there that fat t12, got another 2 of them spare and think in its 30 odd years life its only had 2 or 3 tubes in. thanks again and will double check tomrow.

 

[RF Lighting]

Sounds like the tube has gone. I used to work in a mill with lights like that. You could get the tube to strike by switching the fitting off and on again quickly. Replacing the tube normally cures it.