2007 Komatsu WA370 Loss of steering and implement function

I looked at this loader Sn. A33026 last week for some people looking to purchase it. I got a call a little while ago and they bought it today and have run it about seven hours or so and the hydraulics stopped working on the steering, boom and bucket. When I looked at the machine I noted a little shudder when the boom was lifted at low idle, but the cycle times were good. I took oil samples on the rig as part of the inspection and all came back good. I told the operator to check and cycle the hydraulic safety lever which he did and it made no difference. I also asked him to check all the fuses he could find, which he did and all looked good. He didn't have a test light or multi meter to check with. I'm looking for any possibilities of things that aren't the hydraulic pump or the hydraulic pump drive. I'm also looking for information on how to get into the diagnostics if the machine has it. There are two rocker switches on the right side of the steering wheel. One cycles through a couple of menus and the other gives you a couple of sub menus from the other. I haven't had the opportunity to get into these hystat machines so I don't have much of a clue. Any help is greatly appreciated.