Fueling our Schadenfreude is probably not good for our karma (so is mixing metaphors in two languages), but the Designed By Monkeys column would get a big readership boost if a representative from the company in the crosshairs tried to explain design intent. Watching the representative squirm after being subjected to the monkeys would certainly give enjoyment to so many readers.
They don't need to admit liability, but boy, it would be nice to have an answer to "What were they thinking?"
Undersized transistors in this instance are pretty obvious - cost savings by not having fewer unique parts leads to the result in this MbM. However, the lightbulb protected by security torx fasteners should be answerable.
There's no liability in discussing that design choice; the readers in general, and engineers / designers might learn something interesting in the design choices available.
It might be a new quarterly column (figuring that large companies have more inertia and will take time to come up with something). you could call it:
The Monkeys Strike Back
Joking aside, there might be valid reasons for the design choices made; we would all benefit to have a few explained.
I like this idea, TJ. I am always thinking when I read these stories that I can't imagine how the companies and product designers would let something slip through quality assurance like they seem to, so to have them weigh in on what went wrong and how this could have happened is a great idea. I also like the title! Clever. :)
I once worked at a major consumer product company which I will not name because Texas Instruments would get mad.
My project manager insisted on using one RC network to clock TWO micros that had RC-based oscillators using Schmidt trigger inverters. (TMS1000 era..early 1980's).
I explained to him that one of them would have a lower threshold than the other, and thus, only one would clock. Therefore, TWO RC networks were needed. I changed the BOM. Later, I found he changed it back. This made for a funny argument.
To presume that there is a rational decision making process in place for ANY thing is risky. I have made a career out of uncovering the 'why' of problems like this and later, when I ran a contract manufacturing company, my 35 customers and 400 products gave me scores of chances to see how stuff gets into products. I've even done it myself. No one is immune from mistakes. I've found them in dental chair electronics, hospital bed electronics, dog collar electronics, hydraulic presses, missles, test equipment, cryogenic freezer controls, ad infinitum.
This one looks par for the course. Some designs are perfect for some installations. None are perfect for all. This guy found a 'breed weakness' and a questionable feature.
The viewing angle of the display is controlled by the polarizing material in front of it, and I prefer the better visibility straight on to lower visibility at some angle. Of course, my Panasonic inverter oven is mounted so that the display is at almost eye level, whyich makes some difference.
If the light were to come on whenever the door were opened it would take more switching, and a bit of logic, since it is also on while cooking. My guess is that at least some of those applications use the light for a snubbing resistance while the magnitron is active, which would make having it on when not cooking even more complex.
As for the lamp being hard to replace, my guess is that the intention is that the unit would be replaced by the time the lamp failed. That is quite common in small appliances currently. Besides that, Panasonic brand electronics has never been easy to work on or service. That goes all the way back to their early cassette recorder days. Those units did not seem to be built with the concept that they would ever be opened again. Som traditions are difficult to change.
See also my posting about the door latch problems on this same product line.
Fauxscot, I agree the breed weakness would never be willingly discussed, but the choice of fastener should be.
It may not even be a questionable feature - we may learn that the product is assembled soley with the one type (and size) of fastener, and that changing the fastener holding the light bulb cover to a different type would greatly increase the fastener assembly time, stocking, etc.
Maybe the designer did evauluate that security torx drivers are not all THAT difficult to acquire. The combination of cost and consumer tool availability makes the design choice not quite so simianly sinister.
These are all my suppositions though, and we won't know unless some manufacturer steps up and tells us. In the right forum (such as right here with Design News), civil questions may be asked and some new understanding gained.
Of course, we could be not so civil, begin throwing the metaphorical poo, and then WE'D look like the monkeys.
The lightbulb one is simple maths. Total product lifetime = 10 years. Total daily usage < 20 min (if it's more than that, you should see a dietician and you should be eating more real food, not warmed up leftovers and TV dinners). Total lightbulb usage over product lifetime = 1000 hours . Lightbulb manufacturers data says lifetime = 2000 hours. So design engineer reckons that the lightbulb should never need replacing. (Thermal cycling is another parameter to consider, though).
The LCD visibility is probably a matter of economy. You can obtain a wider viewing angle with less multiplexing, or better yet, a static display, but more pins for less multiplexing means more money. I've worked for a bunch of appliance manufacturers, even the huge stainless steel companies, and rarely is a decision made that favors performance over cost. The conversation with Marketing and Engineering would sound something like a Dilbert script.
Marketing: I can't see the display unless I'm looking right at it, my new smart TV doesn't do that.
Engineering: We can widen the viewing angle with a different display and a micro with more pins.
Marketing: You need pins to fix it? Great, go get some more pins.
Engineering: The new display and larger micro will cost an extra fifty cents on the Bill Of Materials.
Marketing: Fifty cents for more pins? Forget it, nobody will pay that much just to see the clock.
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