This military 7603N has been sitting under bench 2 and behind the scope cart for nearly a year. When I purchased the 7904 it got kicked off the scope cart and basically forgotten. So today I pulled it out, dusted it off, and powered it up. Came up fine except the left 7A15A plug-in had noisy attenuator switch. IPA to the rescue.
I've not done much to this scope other than knock out the dents in the covers and re-paint. Checked and adjusted the +50V reference and cleaned any noisy pots/switches. Burned it in several times and called it good.
I wanted to re-cap it but it looked like getting to the PSU was going to take some major disassembly. So I left it. Well all I had to do was RTFM and discovered that the entire PSU pulls out the back after removing 6 screws. The last pix shows it partially pulled out. There's a bunch of connectors that have to be pulled so I didn't go any further. But yes, I'm going there. It's going to get a PSU re-cap. And we can debate the merits or stupidity of doing that ad nauseam but I'm convinced for long term reliability it's the right thing to do.
In the meantime it's going up on the torture rack to get some power up time.