If someone is randomly swapping boards in a piece of equipment to try to fix it, they are asking for trouble and will probably get it. Having an understanding of how a piece of equipment works as well as technical documentation is critical to finding a problem quickly and safely. In my case, I have qualified engineers on staff to troubleshoot and repair our equipment and keep the facility functioning. The reason we are doing more board-swapping is based upon how OEMs have designed their equipment and the economics of repair.
First, at a systems level, broadcasters are consolidating their facilities to take advantage of the economics of scale by doing more with what they have. That means adding more revenue streams by having more cable channels that are little more than another automated playlist and a simple master control(M/C)switcher added to an existing facility and expanding the infrastructure.
Second, facilities like these have large items like a router that can be expanded (in our case) to 1024 x 1024 (that's the chassis limit) and we add I/O cards as necessary to handle more sources and destinations. Some manufactures have added extras into simple routers like M/C switchers on an output card, multiviewers (allows one large LCD display to show many router sources at once with a browser-based software application for configuration) and shufflers (which allow reconfiguring of embedded audio in A/V sources among other things)to add more 'flexibility' to their product. It works fine when it works but when it breaks it's usually not at a convenient time. So, spare boards and maintenance agreements are used to reduce downtime. In our case downtime can literally translate into millions of dollars. A Super Bowl spot can cost up to $2 million but that's an extreme, if often quoted example.
This brings me to my point (finally!). My staff will troubleshoot a problem and if necessary call the OEM to narrow down where the problem is and then they send us a replacement part. (For critical systems we do maintain a set of spare cards but that can be a quite expensive way to tie up capital money that's not doing anything until that one critical failure occurs that was anticipated.) 90% to 95% of the time that fixes the issue. But if not, then Engineering management will step in to expedite the issue and, if necessary, and OEM rep will arrive to figure out what's going on.
What I'm saying in a long-winded way is that boarding swapping is a compromise between keeping a facility running and keeping costs down. It's great fun to sit down and spend the time troubleshooting an piece of analog gear with a scope and multimeter, but in this day an age board-swapping is the only economic way to go. And that's why OEMs build their equipment that way, it's what broadcasters want to save on costs.
When commodity items like LCD displays or PCs act up for any reason, we just replace them and dispose of the broken stuff, it's just not economically feasible to repair them; though it does break our hearts. We all hate to see repairable equipment go to waste.
Anyway I've blabbed on long enough. I haven't even mentioned trying to replace surface-mounted parts that you need a magnifying glass to read or the desoldering station needed to replace ICs on a bad board. The horror stories I could tell about boards being butchered when someone thought they could just fix it. BTW, if we damage a board trying to fix it, the OEM won't accept it for repair and we have to buy a NEW board. It's no fun going to the VP of Engineering and explaining why we have to spend $20,000 for a new board. I happen to like my job so being conservative about repairs helps to keep me employed.
On a personal note, no matter the challenges when trying to repair an item, there is no greater sense of satisfaction when you fix something that was broken by replacing a some small part. My wife has the mindset of if it's broken it has to be replaced and she sees dollar signs. So when I say I fixed it by replacing a $1 part, she is always amazed and grateful for a husband that can fix stuff (usually). It helps to make up for other stuff I can't do, like dance.
Gerry
