Announcement

**Enzo** · 07-09-2010, 01:11 AM

At one company we used to mess with the new guys - nothing cruel, just fun.

One guy, Dave was great, we loved him, but he was the perfect patsy. One day we got under his dash board and jumpered his brake lights to his horn. It was priceless. He took off for lunch and got to the corner stop sign and HOOOOOONK. A few more honks and he got out of the car to figure out what was happening. Unexpected bonus: he flipped on his emergency flashers, and ...voila...honk...honk...honk...honk... He tried to get me back with a potato in my tail pipe, but it fell out when I started my car. He was so disappointed.

My favorite shop prank though was the young fellow who wanted to work on his car out in the driveway during his lunch hour. He needed to drill a hole in something on his car. SO he ran a long extension cord out the door and into the driveway. We could see him out the window. As he walked out, I quick plugged his extension cord into my variac. As he started to drill, I cranked the voltage down so the drill slowed to a crawl. He lifted the drill and pulled the trigger a couple times, but I had turned it back up. I let the drill work fine until he tried to use it, when I dialed it back down.

He started to get frustrated, so he came back into the shop to check the extension cord. By then I had removed the variac and left it plugged into the wall, and we all managed to look innocent. he checked the plug and went back out and we did the thing all over again. Holding the drill up it worked fine, but drilling made it slow down, or so it seemed. He even did the thing where he aimed the drill at his face and triggered it, as if looking down the drill bit would explain anything. Oh if only it had been a garden hose. After fighting this a while, and after three trips inside to recheck the extension cord and even try a different outlet, we could contain ourselves no longer and let him see what we were doing.

**Chuck H** · 07-09-2010, 03:03 AM

LOL!!!

Priceless. Did actually LOL.

Chuck

**Chuck H** · 07-09-2010, 03:32 AM

Enough about the guy's you've seen come and go. How about a goofy mistake YOU made as a junior tech...

I've never been a tech. But since I do know a little about amps I do repairs for friends and their relations often. My best mistake was a circuit mod I did on an old Traynor VoiceMaster PA. After the mods I decided to "correct" the usual warpage on the eyelet board and the insulation board. I figured that years of vibration might eventually detriment the insulation on the leads that were sandwiched between them. I stuck a piece of rubber tubing between them to keep them apart. Good idea... Not. I used automotive vacuum tube. As it turns out the amount of carbon in automotive vacuum tubing is enough to make it a semiconductor. All kind of wierd problems were popping up and I just couldn't figure it out until the tubing itself started to smoke and burn!!! So much residue was left behind on the old fiber eyelet board that I ended up replacing it... PITA. Hey guy's, Don't ever try to use automotive vacuum tubing as an insulator.

Chuck

**Enzo** · 07-09-2010, 05:46 AM

Mistakes, I've made a few,
but then again too few to mention
let's see, what did I do
when I did not pay attention?
I planned to do it right
but then I did it in the long way
and more, much more than this, did it the wrong way

With apologies to Frank Sinatra

(he was a popular singer... a long time ago.)
(before the Beatles)
(They were Paul McCartney's band before Wings.)

Oh geez, I have busted myself before here, but I guess making cables without the plug shell doesn;t count.

I learned a lot about field service in the amusement industry. You do have to learn resourcefulness. You service call to some bar on a friday night when it is hopping and the jukebox crapped out or the pool table is jammed, and you BETTER get it going. One guy one time made a contact spacer for a relay out of a cigarette filter. It only needed to last the night, and it did.

Pinball machines have three major sections - the head box where the scores are, the playfield where the balls are, and the main relay board in the bottom. They all connect together with fat cables of many wires plugged into long row connectors. I went on a call one night to cure some problem, and the thing only got worse. None of the voltages were working, relays that should work other relays didn't, lots of stuff not working. After 3-4 hours I gave up. They sent someone else on it the next day. It seems I had carefully plugged the cable from the playfield back into the playfield, the headbox into itself, leaving the relay board to plug into itself. I am surprised it even lit up at all.

Not sure how junior I was, but early on I had a guy's Seymour DUncan SS bass amp on my bench running. It just needed some basic maintenance job. I left it running and removed the lid - or tried. It seems that all the screws came out freely but one, and that last one had cracked the threaded insert free of the chassis wall. As I turned out the screw, that threaded insert fell right into the middle of the power amp section and burnt it to a crisp. "Um, I'm afraid your amp will take a little longer than I thought..." (no, I didn;t charge for that part of the repair.) Apparently the idea that one should always turn the damned thing OFF before taking a screwdriver to them hadn't sunk in.

I know I've told it before, but one of my favorite troubleshooting experiences involved a Yamaha 4 channel cassette deck. The junior tech was working on it, and I don't fault him in the slightest, after all, I had no more clue than he did. I forget the model, MT44 sticks in my mind. (model number correct) A nifty Yamaha product, it was actually three things. It was a 4-track cassette machine, a small mixer - I forget, something like 4 or 6 channels. and a small patch panel. These were all mounted in one housing, but could each act by itself, and you could separate them.

Junoir tech finds the thing will record OK in tracks 1 and 2 but not 3 and 4. All tracks will play back, unit works fine as standard stereo deck. he can;t figure out why it won;t work on 3 and 4. I decide to help. To make a long story short, I told him to look at what turned on the record light or some final point in the record chain, we found that, then further back, what made THAT happen, we found that, and so on, we troubleshot back further and further, through the R/P switch, through this and that, verifying proper function each step. Eventually, we got to the beginning of the system, where the circuit initially was activated by... a photocell behind the cassette.

We discovered that the deck worked as a standard stereo deck, and ONLY would work as a 4-track if you placed a reflective foil sticker on the cassette label for this sensor. We had troubleshot the 3/4 record function completely through the system and out the other end. The system was working operfectly, it was US who was defective. Never occured to me to glance at the owners manual.

One shiny sticker later, and the thing worked fine.

Junior tech started grousing about how we had wasted a lot of time. I told him , no, we learned about how the system worked, plus we demonstrated that our troubleshooting techniques worked. True all we discovered was our own ignorance, but the prodecure did indeed find the problem. "And besides, you are not paid on commision, you work by the hour. Quit your grousing."

SOmehow I am reminded of the old farm lore: tie a string to a piece of food and feed it to a goose. soon enough the string will come out the other end of the goose. Now you have a goose on a string.

No, there is no hidden meaning there, just some interesting imagery.

**jrfrond** · 07-09-2010, 04:30 PM

I watch any interns we get in like a hawk to see what they are doing and if they are listening. As far as the rest of my techs go, who ARE experienced, I watch THEM too, with one eye open, just to make sure they aren't short-cutting things, e.g. series or parallel resistors or caps for a custom value, cutting/tack-soldering component leads, improper component substitution, improper PCB crack repairs, sloppy soldering, etc. That sh*t doesn't fly with me here. Unless there is no choice, something should NOT look obviously repaired or amateurish.

My biggest problem with young techs out of school is that they don't want to learn things in steps and want instant gratification. No one wants to crawl before they can walk. Conversely, I have OLDER techs who work for me that STILL have trouble using the computer to search things, because THEY don't want to learn either!

I've learned that ALL techs need to be kept on a leash, some shorter than others. It goes double for piecework techs, who often develop a mercenary mentality of kicking stuff off the bench before it's time. I like to keep the bounceback rate very low.

**rf7** · 07-09-2010, 06:37 PM

In the 80's, at Hughes Aircraft, when people could smoke anywhere they wanted, the trick was to take a straw and blow smoke into the back of a unit that someone else was working on. That guy would see the smoke out of the corner of his eye, and freak out and shut the machine down. Everyone else would be busting up laughing, and the guy would ask what was so funny, and then we'd let him in on the joke. Good way to give someone a heart attack, I guess.

Another story: My first day on the job at a recording studio, the chief engineer gives me a box full of parts and a few bags of new parts. He tells me that the box contains a completely disassembled Akai cassette deck transport, and could I put it back together with the new parts in the bags? That was a monumental pain to put together, since I did not take it apart!

**Mark Black** · 07-09-2010, 10:37 PM

In the 70's, in what seems now like a previous life...

I was one of the senior mechanics at a motorcycle shop. The new(est) shop helper was very young, very earnest, and pretty clueless (but a really nice guy).

One day he asks out loud how to turn on the solvent tank pump so he could clean some parts. Now the solvent tank was a pretty standard tub on legs with a flexible spout (kinda like a mic stand gooseneck), and the on/off switch was a featureless plastic square actuator (not looking anything like a switch) near the base of the spout.

Being the helpful guy I am/was I promptly went over and told him "look - it's kind of old & weird but this is how you do it". I grabbed that flexible spout and started.....well.........jacking it off. Meanwhile I also surreptitiously hit the on/off actuator with my elbow. I proceeded to turn it on.....then off using the same routine and then stepped back to let the hilarity begin.

Anybody who has worked in a close-quarters shop with multiple workers and a new guy will know that by this time everybody was kinda looking over that way, and it didn't take any time at all before we were all doubled-over with laughter watching the guy try mightily to get that tank going. Seems he hadn't caught my elbow trickery, but boy could he jack it!

**creatorlars** · 07-12-2010, 07:30 PM

Originally posted by jrfrond View Post

I've learned that ALL techs need to be kept on a leash, some shorter than others.

Wish I had someone experienced around to kick my ass into shape! I'm a junior tech in a lead position and learning some lessons the hard way. I've been enjoying all these threads.

**Enzo** · 07-12-2010, 11:19 PM

Unfortunately, too many of us are thrown into the sea and left to swim on our own. I sure wish I had some sort of mentor when I was learning and growing up. And I had to learn my stuff on the job and on my own. Boss says, "Here, we now have to service these digital circuit boards." What is this "TTL" we wondered. Had to figure all that out on our own. I recall the first mystery that came up was looking at a board with 100 14 or 16 pin TTL ICs and trying to figure out how I was supposed to change one out. You can unsolder one end of a resistor at a time and pull it out, but those new fangled ICs with their rows of legs presented a challenge. Someone in a distributor's service shop showed me I could cut the legs off the IC and pull them one at a time. And off we went up the learning curve.

Pinball machines went through a change almost overnight. For decades they had been mechanical relay based systems. SOme of the relay logic was pretty sophisticated. But it was still all just switches and relays. Then in 1976, BOOM, they all went digital. Microprocessors controlled things, TTL and transistors drove the solenoids, switch inputs were all now matrixed, and 7-segment neon score displays took over for stepping relays. We had to adapt to that on our own.

**Ronsonic** · 07-17-2010, 03:51 PM

I work for an infamous practical jokester. A man who once ran sheet rock screws up through the second floor of the shop and into the bottom of an Ampeg SVT. He removed them after the tech, sweating and shaking, came downstairs to get help lifting it. The guy who went up to help just lifted it onto the bench as easy as, well, any SVT. This is a man who knows the hilarity of a cheap smoke machine inside a Leslie cabinet or behind a rack of test gear. Shortly after working for him, well he got me a couple. I think it was the series diode on the input of my scope that did it. Maybe the electric motor with eccentric weight under the bench wired in series with the test outlet. Don't recall.

I decided a multi-layered nuclear option was in order.

Smoke machine with a flex tube that would pour smoke between his legs at the bench.
I knew that wouldn't ruffle, he'd just flick on the fan over his bench.

The fan blades were piled with non-dairy coffee creamer blowing it everywhere.

Of course there's an obvious response to that foolishness.

The compressed air hose next to the bench was filled with water.

Detente was achieved and a complete moratorium on practical jokes was arrived upon to guarantee mutual assured survival.

**jrfrond** · 07-18-2010, 01:46 AM

Years ago when I worked at Crazy Eddie service here in NY, we all had benches with master AC switches that we would turn off at night. A favorite practical joke was wiring a small 'lytic cap to the AC and taping it under the unsuspecting tech's chair. You had about 5-10 seconds before the thing would pop with a nice, loud "snap". Totally funny!!!

**Gtr_tech** · 07-28-2010, 05:05 PM

I'm surprised the mother of all electronic shop pranks has not been mentioned....the shorting bar across the AC plug gag. I don't participate in "tomfoolery" like that, but I've seen it happen enough.

Enzo will appreciate this since he has worked in the amusements industry.
About 20 years ago I got into the amusement gig working for a route op. I had experience repairing video games but was learning as I went about pinball. I used to carry this silicone based grease in my toolbox for use with the plastic microswitch joysticks that were in favor at the time. They would get torn up pretty fast in some games and the grease made them last much longer and operate smoother. I was doing a service call on a pinball about 45 mins from the shop. I think it was a broken flipper plunger link. After replacing the plunger/link assy I figured hey, lets put a thin layer of that silicone grease on the plunger...that should really make it snappy. And it did make a noticable difference from the other one. So I did the same to the other flipper assy. Next day I get a call from the op saying there was a flipper problem with that same machine and get out there ASAP to fix it. WTF? That was working awesome yesterday?! So I drive to the location, turn on the game, start a game, and oh great....the flippers are slow to return to the "rest" position. Turns out the silicone lube had turned into a nice soupy mush that was acting as a mechanical damping fluid. Cleaned off the plungers, put in new sleeves and all is well again.

Rookie card punched....one experience point earned.

FWIW, the plunger coil sleeves were made of a teflon based plastic and required no lubrication, just cleaning every so often.

**Enzo** · 07-28-2010, 11:45 PM

Sorta AC related.

I have trained a lot of repair techs over the years. And if you have ever been to a factory seminar for some product, I wrote and presented lecture-demonstrations for training. This story comes from the amusement industry, but the idea could be anywhere. I want to see if the techs-to-be are thinking or making assumptions.

My typical pattern is to spend half a day presenting training lectures, then send everyone off to lunch and set up a bunch of machines with problems created in them. In this case pinball machines. One thing about my training exercises, you could always count on one of the number of built in problems to be that the piece of equipment was dead, no sign of life. Maybe lights not working, maybe weak flipper, maybe a lot of things, but also, "dead."

In our shop we used drop boxes - long extension cords with a metal box and four outlets in it. We also used those clamp-on lights with the metal reflector to illuminate the work. I would set up the problem pinball plugged into one of these drop boxes, and a work light plugged into the same box. Machine dead, work light lit.

What they didn't know was that in the box, the four outlets were a pair of duplex sockets wired in parallel, and I had loosened one of the wires, so one set of outlets was hot and the other was not. techs who were too close to the problem would be checking the game fuses, the power cord, the switch, the power supply connections and on and on. They "knew" there was power in the outlet because the shop light was plugged into the box and working.The smart ones checked the outlet. The side with the light was hot, the side with the game plugged in was cold.

The lesson was that the problem is not always INSIDE what you are working on, and never assume. The exercise was to make the machine work, not to find only problems within its walls.

**bkahuna** · 07-29-2010, 03:24 PM

That's great story, Enzo. I'm certainly guilty of being too close to the problem sometimes, like the time I troubleshot an intermittent signal from the speaker all the way through the amp to a bad guitar cord! This was one of my own cords that I use for troubleshooting all the time, but it had developed an intermittent open over time. (In my own defense, it didn't really act like a bad cord). There's nothing worse than having problems with your test equipment (including cables and adapters). You want to be able to assume that your test gear is ok, but it's not necessarily so. If I find ANY deficiency in any of my test gear, I usually stop what I'm doing and fix it immediately, before it rears it's ugly head again!

Announcement

Junior tech stories

Junior tech stories

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment