If the player has at least 65 Repair they can proceed directly to the Nellis array and fix each broken unit.
If the player has less than 65 Repair they must proceed to HELIOS One and retrieve the parts. HELIOS One is just north of Gibson Scrap Yard, which is just north of Novac. If you have not yet done the quest That Lucky Old Sun, an NCR Soldier will try to prevent you from entering. Use Speech or Science and convince them to let you pass or you can use a Stealth Boy to sneak past her (Sneak skill alone doesn't work). Go through the HELIOS One building until you get to the door that leads to the outside fences (if you entered through the main door, it's off to the left of the front desk. Going to the right leads to the doors that lead outside of the fenced in area you need to be in. Go straight past the stairs. The 5 parts are scattered around the perimeter fence, but all are roughly between the two terminal stations: you'll find the first near the tents behind the western terminal; walking along the outer row and the fence towards the eastern terminal will produce the next three; the final one is by the tents near the eastern terminal. The parts look like fallen solar panels (you need a Repair skill of 20 to salvage the parts). Once you have all 5, head back to the Nellis array and install them.
With a Science skill of at least 50, the player will also upgrade the efficiency of the solar panels when he/she repairs them, netting 50 XP instead of 30 XP per array repaired this way. If you have not restarted the generator the computer terminal is not powered, so make sure to complete that part of Ant Misbehavin' before you turn this in to Loyal if you want the extra experience. You cannot get the extra XP after Sunshine Boogie is completed.
Once all of the solar arrays are repaired, go back and speak to Loyal for 400 XP (500 XP if efficiency was upgraded) and fame with the Boomers.
Warning: Quest will remain active if you have negative rep with the Boomers. Loyal will be hostile thus making the quest impossible to complete.
The following is based on unverified behind the scenes information and has not been confirmed by canon sources.
The solar panels of Nellis are photovoltaic panels and should not be exchangeable with the panels of HELIOS One. HELIOS One arrays are just mirrors working in order to focus light because these power plant is a solar power tower, with functioning that consists of focusing solar light on the central tower, which is a huge solar furnace which generates heat to feed a turbine. This can be observed playing the mission That Lucky Old Sun. Even so, it doesn't matter for the player character who can repair Nellis arrays with HELIOS One panels.
End of information based on unverified behind the scenes information.
PCPlaystation 3Xbox 360 Sometimes Loyal may not be found at Nellis and the marker will lead you to Black Mountain. [verified]
PCXbox 360 Sometimes, Loyal will not acknowledge that you've repaired the arrays, leaving the quest unable to be completed. This could be because the Helios One panels were acquired before beginning the quest.[verified]