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Repair Mistakes & Blunders - what bonehead move have YOU pulled??

I guess I've been lucky compared to you moe-rons :p

It's been almost 30 years from the time I was checking valve to piston clearance on a Harley Sportser engine and using clay on the piston. The engine gets assembled and turned over, then the heads come off and the depth of the modeling clay is measured, that's the clearance. The clay is cut with a sharp razor, and sectioned where need be. After I determined the depth was enough, I left the clay on the piston and re-installed the heads. It was on my way home I realized what I did. It was a 16 hour day, half of it spent working on the HD engine.
 
My Oracle Delphi was knocked off its perch during the Ca. Northridge quake which sheared the needle off my Monster Genisis 2000 cartridge.
So I went down to the FEMA office and filled out a form to be reimbursed and stood in line for three hours, listening to people being reimbursed for T.V.'s, broken windows, etc. etc. etc.
They called my name and I went up and the guy looks at my claim,held out my hand with my cartridge in it and he yells "Next."
Waste of a day.
 
onwardjames said:
My mechanic redid my timing belt and water pump on my Miata at 175k. Not 300 miles later, the pulley bolt breaks, and the whole thing has to be done again. 480 bucks I felt that should have been adjusted the second go-around.

That guy later committed suicide by hanging himself in his garage from a water line. The line broke, and cops found 2 feet of water, him hanging from what was left, and the sweet dog he had very happy to be found and taken away. Very effed up.
Click to expand...
That escalated quickly...
 
Bypassed the interlocks on a Gates BC-1J 1kW AM transmitter so I could pull the back and see what was going wonky inside. 3500V later...well, you can figure out what happened:( An engineer I knew was doing battle with a 20kW FM transmitter and got so pissed at it that he flung a wrench into the guts. Wrench landed RIGHT ACROSS the terminals of the main filter cap. 8800V blew that wrench out like a cannon...hit him in the face...broke his jaw, took out a bunch of teeth.
 
mgosdin said:
Went to remove the bottom cover on my spare laptop ( DVD Drive has died. ) yesterday. Got all the tools out, found all the screws I thought I'd have to remove, even found a How-To Video on YouTube.

Thought I'd better scan thru the video. The tech moves a catch switch on the bottom, and off pops the cover.

I do a double take, play the video again, play the video a third time. Then I release the catch and ... pull the bottom right off. Easy Peasy.

Found out the ribbon cable is broke on the drive, buttoned it up, then put away all my tools. An hour plus invested in setup and put away of tools, 5 minutes to open and diagnose the problem.

I shudder to think what would have happened if I'd taken all those screws out.

Mark Gosdin
Click to expand...

Same thing happened to me on my music only refurbished HP lap top, first tool less access laptop bottom cover removal I ever experienced.
After nearly cracking the bottom cover by prying with flat head screw driver, all the while thinking it was just snapped in place, with a running cussing commentary, my caregiver siting at the kitchen table watching me quickly looked up w/ her smart phn; the laptop video on youTube, and showed how simple it was using the battery latches. oh well, won`t forget that anytime soon.
 
No damage done, but very embarrassing ;
Back in the early eighties, my childhood guitar playing friend brought me his band`s PA Sunn rack mount SS power amp for repair.
Both channel`s output stages were failed.
So, I unsoldered & pulled all the T0-3 outputs/drivers that were all soldered to strip circuit boards on the back side of the heat sinks to check them for shorts & leakage.
Found all that were outright bad, and leaking, and or believed to be suspect..
No problem, as I had done this type of SS power amp rework many times before, just not on any recently released Sunn Pro line amps.
And being the band needed this amp fixed very soon, as a gig was coming up soon.
So I quickly ordered the defective TO-3s, but no time for obtaining the SM(pre internet !), so I thought, no problem, I`ll call Sunn customer service and get a tech to tell me the bias voltage, and or current settings.
Well I carefully variac the amp up, before I call, and noticed it`s main`s idle current, is surprisingly very low, to my way of thinking, and all output devices are very cool to the touch with the case collector rail voltages present !
The B &E connections could not be reached after the output stages were reinstalled.
Anyway, I get the Sunn tech on the phone for some setting`s information about the amp, only to find out no adjustment of the bias trim pots aren`t doing anything, that`s when it occurred to me while I had the guy on the phone, that I didn`t solder all the transistors B & E terminals back to the circuit board, on both channel !

So I informed the tech. of what I had not done, and thanked him for his time and the information about the amp.
Tore that sucker back a part, and sure enough, every one of the power devices circuit boards had nice clean holes & no solder on the devices pin`s.
Re/soldered all, put bias trimmers back to their previously marked positions, and re-variaced the amp back up.
Let it idle for a half hour, set DC bal, and bias and ran full factory tests, and all was good.
Yep, this guy had a beet colored face, but in my defense, sensitive rush jobs, are always risky !
You can bet that never happed again.
 
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when I was new to dSLRs (2003) I jammed a CF card into a digital Rebel the wrong way bending a bunch of internal pins. Stationed on Oahu at the time...I think
that was a 200$ miscalculation.
 
I had a Marantz CD-94MkII that stopped playing. I repacked it in the original box, with the transit bolts in place. Took it to my repairer, and after a couple of weeks, I collected it. When I tried it, it wouldn't play. Annoyed, I took it back. After a week I get a call saying "no fault found". I collect it, put it in my system, and it doesn't work. Took it back again, they rechecked it and didn't find a fault, but when I returned home it still didn't work!

Very annoyed, I went back to the repairers. They were quite confused, and this time wanted to demonstrate that it was working well while I was there. They took it out of the box, and I noticed they removed the two transit screws from the bottom. It was then that I realised that I had only been removing one transit bolt, even though I had originally put two in when I boxed it up! With the two transit bolts removed the player worked perfectly. I admitted my error to the tech's when i observed it, but the error was so stupid that they had difficulty understanding it!
 
electronjohn said:
Bypassed the interlocks on a Gates BC-1J 1kW AM transmitter so I could pull the back and see what was going wonky inside. 3500V later...well, you can figure out what happened:( An engineer I knew was doing battle with a 20kW FM transmitter and got so pissed at it that he flung a wrench into the guts. Wrench landed RIGHT ACROSS the terminals of the main filter cap. 8800V blew that wrench out like a cannon...hit him in the face...broke his jaw, took out a bunch of teeth.
Click to expand...

Had the same experience on the Gates BC-1J transmitter. A very crochety example, which liked to go Pop & Bang too often. And was in a less than hospitable environment of a transmitter shack. It had taken several really bad direct lightning strikes. Never had air conditioning in the summer, and lived in a less than clean environment. And still ran though it always was moody until that day. Turned out to have the plate and modulation transformers shorted. After it discharged that one last time, it was dead. One week later, the station was sold, the new owners built a new air-conditioned clean transmitter building which was larger, as they also got a FCC construction permit approved that week to build a new FM. A brand new Collins Power Pebble, and a new Collins FM arrived in 10 days, we had a LPB AM transmitter to keep on the air from the old building until the new one was built. Both transmitters are still in superb condition, both are now standbys to the new Nautel pair which replaced them 6 years ago. From dump to pride and joy.
 
I picked up a Fisher 90R tube tuner for $4 at an estate sale and thought I'd clean it up. Mono only, but it had "Microbeam tuning" - a specialized, very cool, tube behind a window that acted as a tuning meter. I took it apart and started to clean it up, but made the mistake of using acetone on the back of the glass. All of the dial numbers and input selector text were printed on the back of the glass. "WERE".
 
Bill Ferris said:
No damage done, but very embarrassing ;
Back in the early eighties, my childhood guitar playing friend brought me his band`s PA Sunn rack mount SS power amp for repair.
Both channel`s output stages were failed.
So, I unsoldered & pulled all the T0-3 outputs/drivers that were all soldered to strip circuit boards on the back side of the heat sinks to check them for shorts & leakage.
Found all that were outright bad, and leaking, and or believed to be suspect..
No problem, as I had done this type of SS power amp rework many times before, just not on any recently released Sunn Pro line amps.
And being the band needed this amp fixed very soon, as a gig was coming up soon.
So I quickly ordered the defective TO-3s, but no time for obtaining the SM(pre internet !), so I thought, no problem, I`ll call Sunn customer service and get a tech to tell me the bias voltage, and or current settings.
Well I carefully variac the amp up, before I call, and noticed it`s main`s idle current, is surprisingly very low, to my way of thinking, and all output devices are very cool to the touch with the case collector rail voltages present !
The B &E connections could not be reached after the output stages were reinstalled.
Anyway, I get the Sunn tech on the phone for some setting`s information about the amp, only to find out no adjustment of the bias trim pots aren`t doing anything, that`s when it occurred to me while I had the guy on the phone, that I didn`t solder all the transistors B & E terminals back to the circuit board, on both channel !

So I informed the tech. of what I had not done, and thanked him for his time and the information about the amp.
Tore that sucker back a part, and sure enough, every one of the power devices circuit boards had nice clean holes & no solder on the devices pin`s.
Re/soldered all, put bias trimmers back to their previously marked positions, and re-variaced the amp back up.
Let it idle for a half hour, set DC bal, and bias and ran full factory tests, and all was good.
Yep, this guy had a beet colored face, but in my defense, sensitive rush jobs, are always risky !
You can bet that never happed again.
Click to expand...

I've done that too!! Get too used to working on gear with transistor sockets, my muscle memory tells me that once the screws are tight, I can rest easy the transistor has been installed - even if I desoldered the old one moments before!
 
Stephen300 said:
Nothing chaps my ass worse than soldering two wire ends together and then realizing I forgot to put the heat shrink on first.
Click to expand...

How about putting on an RCA or 1/4" phone connector, and realizing you forgot to slide the cover up onto the cable first? I can't count how many times I've done that while in a rush.
 
maxhifi said:
How about putting on an RCA or 1/4" phone connector, and realizing you forgot to slide the cover up onto the cable first? I can't count how many times I've done that while in a rush.
Click to expand...
That would come in second on my list only because I’ve soldered far more wire to wire connections than connectors in my life.
 
Stephen300 said:
That would come in second on my list only because I’ve soldered far more wire to wire connections than connectors in my life.
Click to expand...

I'm inclined to just say screw it and use 3M electrical tape, when that happens. Unless it is a critical application of some kind.
 
Nixxuz said:
That escalated quickly...
Click to expand...

Yeah, it truly did. RIP, Al Lolli. Oh, and the two events are not at all related. Seems he had some real demons.

electronjohn said:
Bypassed the interlocks on a Gates BC-1J 1kW AM transmitter so I could pull the back and see what was going wonky inside. 3500V later...well, you can figure out what happened:( An engineer I knew was doing battle with a 20kW FM transmitter and got so pissed at it that he flung a wrench into the guts. Wrench landed RIGHT ACROSS the terminals of the main filter cap. 8800V blew that wrench out like a cannon...hit him in the face...broke his jaw, took out a bunch of teeth.
Click to expand...

This also escalated quickly. I'm reminded of two dumbass moments in my own life -

About to play a HUGE gig in front of 3k screaming co-eds, and my chorus pedal wouldn't work, some weird issue, so I haul off and punch it.

Broke the knuckle on my right hand.

Another time many years later, I'm trying to break up a dogfight that had happened over a pig ear (dogs get odd when pork is involved).

I had to cinch up the collar on my own very strong dog to get him off the other one, and I hear and feel a pop. Turns out, I had twisted, and broke, the pinky on my right hand.

It has a very odd bend to this day. Won't fully straighten out. Not Tom Hardy finger bad, or Denzel bad, but it is there.
 
Dazaa said:
I did exactly the same thing when changing the shifter cable on my Vette, 10 minute job from underneath, 5 hours and lots of blood loss doing it from the hole under the shifter. All because I couldn’t find my jack.
Click to expand...
Shifters!
Years ago I replaced the shifter bushings on the transmission end with spherical bearings - replacing the brass bushings because, you know, it would make the car go faster.
One of the spherical bearings was a bit wobbly so I figured I should replace it, just to discover that (1) I installed it upside down and (2) it was seized to the steel transmission linkage post.
After messing with it for hours (from top and bottom) I finally realized I could just remove the linkage part with one bolt.
A quick trip to the grinding wheel and it was off.

I replaced it with the old brass bushing, which was fine.

I’m always going down the road of trying to improve things that are just fine as they were.
 
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