Self Repair?...Let's be aware...
I found my knack for figuring out how things worked by literally taking my toys apart and trying to mangle things together to see what I could make work, or not. I didn't always wait for them to break or go faulty either. My Father found it vexing at first but soon realized what was quickly developing. He started buying me more complicated things with electronics and radio control and I probably nearly burned the house down twice splicing and experimenting - all before I was 10. We developed and installed our own centralized vacuum system for our home and it worked a charm. We were the only ones in town that had one back then. I learned that batteries don't like being shorted out and that fuses were essential if you wanted to continuously attempt to blow something up. Eventually in my teens I was fixing everything from my neighbours appliances to my local Barbour's strimmers. I got a great sense of achievement in figuring something out or repairing something that was otherwise for the garbage. It was a learning "zig-zag" more so than a "curve", but it all played a big part in shaping and moulding my place in working life. I knew early on in school what I most likely wanted to do would be somehow technically challenging. Self repair at an early age certainly played a huge role in getting me to where I am today.
Having said that, when it comes to the professional world, I would err more on the side of caution with certain OEM equipment and attempting self repairs. HMI terminals would be one of those. For me, it's not as much about whether I can or cannot, but more about whether I should or should not. I would have to stand over any repairs I've carried out myself where the manufacturer has specifically stated not to do so. If something fails, or worse, then where does that leave me, the resonsible person?
I used to contract and had many customers. For my customers, I would prefer the guarantee or warranty provided by an authorized repair service over the uncertainty of carrying out a self repair. I now work for a multinational and while my responsibilities are now focused to just one manufacturing facility, I am still responsible for the installation, programming, maintenance and repair or replacement of our Automation install base. If any equipment goes faulty I do not entertain any of us attempting a repair if the manufacturer states it's not recommended.
Again, it's not about whether we can do it or not, or even if we agree that it's a simple repair; it's about the onus of responsibility it places upon our department and it's Engineers. It's also about efficient use of our time. If a HMI goes down, backlight or not, we replace it with a spare and then deal with the repair or replace side of things, in our own time.
Of course, just because you've had an authorized repair service carry out the work, it does not mean something cannot still go wrong. But again, what's important is that the buck does not stop with us.
I've mentioned several times before here on the Forum how we've used Lektronix regularly for our equipment repairs, including PanelView Plus 600 backlight replacement.
Here is one such previous mention...
http://www.plctalk.net/qanda/showthread.php?p=735512
Regards,
George