Ati lighting help

[runfrumu]

6 bulb Ati sunpower, All 4 bulbs on channel 1 will come on, but then 2 will shut off and not come back on after an hour or so. I have changed the ballasts and the bulbs and it still does this. Could it be an end cap causing the ballast for those 2 bulbs to shut off? This started happening after changing bulbs and I’m at a loss

Thanks

 

[JustAnotherNanoTank]

I would definitely check the connections at the bulbs and make sure there is no corrosion going on in the end caps.