I'd say about 90% of the calls I get for our McDonald's stores are repaired the first visit. However, there are times where I find a common problem that looks like the cause of all the symptoms and then get a call back a few days later and find a different more rare and harder to detect problem. Does this happen to you guys too? How in depth do you look at the unit after you've already found a likely problem? For example a walk in freezer drain pipe was cracked underneath the insulation, so the only way I found it was to rip off the insulation. Should I just always check for cracked drain lines? Am I crazy? Are some problems really complicated and hard to find the first time when there are multiple problems that could all cause the same symptoms?