I use 30+ year old magnetics and they still work fine. Had to replace a ballast in one of the HPS ones and will be getting a multimeter that can test for capacitance to make sure they are working properly. They can still fire a light when they get low but light output suffers. Need one for each of my 2 - 1000W ballasts. One is MH only and the other switchable MH/HPS. To test if the capacitor is dead pull the wires off the top and with a multimeter set at it's highest resistance level hold the tips on the tabs on top of the capacitor and the resistance should slowly rise. If it's dead it won't show anything. Bulging tops or leaks are physical indicators that the capacitor is shot.
That reflector on yours is crap for a grow room but you can remove it and mount the socket in another hood but most hoods come with a socket installed. Just run wires from the ballast to the light and you won't have to hang that heavy ballast.
One of my oldest 400W HPS. Using it right now to veg plants with a 400W Philips CMH bulb. I have two like that and a 400W MH very similar. MH and HPS are virtually the same with the same coils and capacitors but the HPS also has an ignitor to fire the bulbs. Mine are wired 120V but can be switched to other voltages like 240.
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