What is the hardest problem that you've ever solved?

[BillyCarpenter]

I was recently reading an article about Elon Musk and they said that when he interviews someone for a job that this is a gestion he asks.


What's the toughest problem you ever solved?

This could be a copier, computer, automobile, TV...anything.


I've been thinking about that since yesterday. I don't have an answer yet. I'm sure I'll come up with something soon.

How 'bout y'all?

[BillyCarpenter]

Re: What is the hardest problem that you've ever solved?

I'm gonna give this a shot. My memory a'int what it used to be.


I guess I was about 13 years old. We had this big eclectic clock in the living room since I could remember being alive. One day it stopped working and my dad took it apart. My dad was always taking things apart. lol.

Anyway, there were what looked like millions of gears, springs and thingamajigs laid out on the table. I woke up in the middle of the night and just started putting it back together. I must have worked on it for 7 or 8 solid hours. Finally the moment of truth arrived. I plugged it into the wall and it ran but it was running backwards.

This confused the hell out of me because I knew nothing about AC or DC voltage. Somehow I figured out to reverse the wires and it started running in the right direction.

I reserve the right to change my mind.

[Drivee]

Re: What is the hardest problem that you've ever solved?

I solve a lot of problems but, fix is always very easy but the problem is to find what to look..when you find where is problem then fix is easy..

[Gift]

Re: What is the hardest problem that you've ever solved?

I solve a lot of problems but, fix is always very easy but the problem is to find what to look..when you find where is problem then fix is easy..

True, but since there's so many different stugg to solve I can't really recall a lot from months or years ago. It's hidden in my passive memory though I can usually recall int he moment I'm faced with an issue (again). All in all I'd totally screw up that job interview but I find that guy pretty mental anyways....

[slimslob]

Re: What is the hardest problem that you've ever solved?

I have had a number of problems over the years. A few have had to do with factory soldering errors that on first examination looked like actual traces or traces missing on boards. Most were on large digital dictation systems. One even had the training instructor from Atlanta stumped. A recorder as soon as it got to heavy usage each day would have one of the drives fail which would generate an error message on the console. The system would continue to operate but without redundancy. I would go there a little after midnight and it would restore mirroring with no problem. The lead instructor flew out from Atlanta bringing along another drive. After replacing the drive the same problem the next day. I got to looking at the actual error message as to what was failing and it was a reply signal going low too soon. I pulled the connector board and finally noticed the the pin for that signal appeared with the next pin which was actually a logical ground lead. It turned out to be a solder bridge. Removed the excess solder and no more problems.

[BillyCarpenter]

Re: What is the hardest problem that you've ever solved?

Just for fun, here's another interview question by Elon Musk.



Can you answer Elon Musk's favorite interview question?

[BillyCarpenter]

Re: What is the hardest problem that you've ever solved?

Here's the answer to the question:































































How to answer Elon Musk's interview question

If you're scratching your head at this brain teaser, you're not alone. Apparently engineers usually solved the problem and guessed the correct answer: the North Pole. Following Musk's directions and using the North Pole as the start location, you'd make a triangle and end up right where you began. Another potential answer could be the South Pole.
The good news: Musk wasn't too concerned with job candidates giving him the right answer. When interviewers ask brain teaser questions like this one, they're looking to gauge the candidate's critical-thinking skills and ability to operate under pressure, not necessarily for the correct answer.
“Interviewers use these questions to see if you can think and resolve issues quickly with what data they present,” TopInteview coach Nick D. says. “The answer is often irrelevant. It's the candidate's way of coming to the conclusion that matters.”

[Drivee]

Re: What is the hardest problem that you've ever solved?

I would say, I am 1km west from starting point. Right.

[BillyCarpenter]

Re: What is the hardest problem that you've ever solved?

I have had a number of problems over the years. A few have had to do with factory soldering errors that on first examination looked like actual traces or traces missing on boards. Most were on large digital dictation systems. One even had the training instructor from Atlanta stumped. A recorder as soon as it got to heavy usage each day would have one of the drives fail which would generate an error message on the console. The system would continue to operate but without redundancy. I would go there a little after midnight and it would restore mirroring with no problem. The lead instructor flew out from Atlanta bringing along another drive. After replacing the drive the same problem the next day. I got to looking at the actual error message as to what was failing and it was a reply signal going low too soon. I pulled the connector board and finally noticed the the pin for that signal appeared with the next pin which was actually a logical ground lead. It turned out to be a solder bridge. Removed the excess solder and no more problems.

Back when I worked for Sharp, they had actual schematics in the service manual and I was working on a SF-7350. The exhaust fan stopped working and the board needed replacing. We didn't have a board in stock so I traced the inputs of the fan back to an IC chip on the board. The chip consisted of "NOR" gates. A NOR gate is a digital logic gate that gives an output of 0 when any of it's inputs are 1.

The only reason that I even remember this is because one of the other techs told the boss what I had done and the boss didn't believe it and he came and questioned me about it. I finally had to show him where I de-soldered a chip from an old board to use as a replacement.

PS - This really was an easy fix because it was a simple circuit and I had the diagram. It sounds harder than it was.

[blackcat4866]

Re: What is the hardest problem that you've ever solved?

Not that it was particularly difficult, but I was unaccountably proud of it:

On the Mita DC-1655 there's a lamp regulator board which powers light source #1 (in this case a halogen lamp). When you'd get a weird image quality issue, one of the service manual checks was to measure the lamp voltage of two test pins on the lamp regulator board. It's located on the front frame of the upper clamshell, right behind the air shock that inconsistently supports the clamshell when it's open.

So I'm measuring the voltage ... and my lead touches the adjoining heat sink and I get BIG SPARKS. There's a 50mm long trace that's entirely vaporized off the lamp regulator board.

Mostly out of curiosity (to see if it would work), I soldered a wire from the connector pin to the transistor at the other end. It powered up, and I was able to do the VR adjustment to restore image quality. When I told the boss about it, he asked me if I was going to replace the lamp regulator board. My response: "Why? There's no reason that it won't continue to work."

As an aside, that machine was in the choir loft of a church up a narrow winding stairway. When we were bringing out the DC-1655, it got away from the the delivery guy, and tumbled most of the way down, wrecking havock all the way down. =^..^=

[BillyCarpenter]

Re: What is the hardest problem that you've ever solved?

Not that it was particularly difficult, but I was unaccountably proud of it:

On the Mita DC-1655 there's a lamp regulator board which powers light source #1 (in this case a halogen lamp). When you'd get a weird image quality issue, one of the service manual checks was to measure the lamp voltage of two test pins on the lamp regulator board. It's located on the front frame of the upper clamshell, right behind the air shock that inconsistently supports the clamshell when it's open.

So I'm measuring the voltage ... and my lead touches the adjoining heat sink and I get BIG SPARKS. There's a 50mm long trace that's entirely vaporized off the lamp regulator board.

Mostly out of curiosity (to see if it would work), I soldered a wire from the connector pin to the transistor at the other end. It powered up, and I was able to do the VR adjustment to restore image quality. When I told the boss about it, he asked me if I was going to replace the lamp regulator board. My response: "Why? There's no reason that it won't continue to work."

As an aside, that machine was in the choir loft of a church up a narrow winding stairway. When we were bringing out the DC-1655, it got away from the the delivery guy, and tumbled most of the way down, wrecking havock all the way down. =^..^=

I'm familiar with that model. Or I was. Are you talking about the heat sink for the TRIAC? I think I remember that.

[blackcat4866]

Re: What is the hardest problem that you've ever solved?

I'm familiar with that model. Or I was. Are you talking about the heat sink for the TRIAC? I think I remember that.

I do remember the heat sink, but I'm not sure about the triac. I am certain that the heat sink was hot, since I've zapped myself with it on several occasions. =^..^=

[slimslob]

Re: What is the hardest problem that you've ever solved?

Just for fun, here's another interview question by Elon Musk.



Can you answer Elon Musk's favorite interview question?


Walk one mile south...


In the early days of Tesla and SpaceX, Elon Musk interviewed every single candidate who came through the doors. It didn't matter what position they were interviewing for — he wanted to talk to everyone.

According to his biography, many of those who sat across from Musk would be asked his favorite brain teaser interview question:


“You're standing on the surface of the earth. You walk one mile south, one mile west, and one mile north. You end up exactly where you started. Where are you?”

That depends on whether you are talking about walking true south, true west and true north or magnetic south, west and north.

One mile south of the north pole (true or magnetic) would be a 2 mile diameter circle.

[blackcat4866]

Re: What is the hardest problem that you've ever solved?

That depends on whether you are talking about walking true south, true west and true north or magnetic south, west and north.

One mile south of the north pole (true or magnetic) would be a 2 mile diameter circle.

As long as we're making this excessively complex, take into account that it would be very difficult to use any compass at the North or South Poles. The needle just tends to spin around randomly at the poles.