Electricion i,m not ?

[aka rotten]

Have 12 flouresent fixtures in my shop that hold 4 bulbs each,wasnt a problem for several years now some of the fixtures only 2 bulbs light others sometimes all 4 come on then 2 will go out [and sometimes come back on].What in your expert opinions is my problem,bulbs,ballest?Told ya,i,m not an electricion.Thanks,Paul

 

[aka rotten]

Thanks for your quick answer,yes i do notice some of the bulbs ,not all do have black area on ends of bulbs,some of them still light when i turn em on,guess my best bet is to buy all new bulbs and go from there.Thanks,Paul