What was your easiest repair ever?

[GreyWoolfe]

I once received a service call for a receipt printer without power.  I spoke with the person on whose desk it sat and asked her to double check the power cord.  2 minutes later she got on the phone and said she did and still no power.  1/2 hour drive, looked under her desk  and pointed out the plug sitting on the floor.  I plugged it in and told her to have a nice day.  The equipment was under contract so she couldn't be billed for stupidity.

[Howardlong]

Tek 2467B, last weekend. "Test 02 Error 04" on startup. It's been like that for a few months, and I'd just got around to looking at it, on the assumption it was going to take a while to fix. When I've had similar looking errors, I've had to either do a re-cal and/or replace the battery backed up RAM or battery, so I took the case off.

Looked up the error, turned out to be a stuck front panel button, fixed in a couple of seconds.

What did I learn? RTFM of course.

[tautech]

I was given Oki 5200 color laser that wouldn't print properly. IIRC the page count was less than 2K.
Turned out to be a sheet of paper wrapped around the fuser drum. 

Several K pages later it's still going strong. 

[rrinker]

 I got a big discount off a used 1987 RX-7 because the display board in the center of the dash (clock, warning lights) was dead. Electrical problems seem to always scare and stump otherwise great mechanics. They don't bother me (I wouldn't have pursued an EE degree if they did). So I drove the car home, and poked around to see how to get this panel out. I popped it out, there's just one electrical connector. When I pulled the cable off I saw the problem immediately - the part of the connector soldered to the panel's board had cold joints on half the pins. I took it in the house, fired up my soldering iron, redid the bad joints, plugged it back in - all worked, and continued to work for the next 4 years I had the car.

   

[mzacharias]

I have worked mainly in audio repair so I've had many. Dirty laser lenses on CD players. Scratchy potentiometers only needing cleaning. Yellow glue turned brown and conductive / corrosive. Tape monitor buttons pressed IN on integrated amps or receivers. Bad solder on FL tube filaments. Bad solder connections generally. Series - connected speaker switches pressed IN for nonexistent "B" speakers. Missing pre/main jumpers on receivers. Screws needing tightening. The list could go on and on.

[JohnWard]

Plasma TV - one of the huge ones which required several people to move it.  Customer said it had no sound - everything else worked.
Not exactly keen to dismantle or even move the thing, so first shoved some audio into one of the many inputs - sound blared out at full volume.

The problem was that the customer only used it with the HDMI input, and that had a menu option to disable the sound so that an external sound system could be used instead.  A few presses of the remote control, and the 'fault' was fixed.

[bitseeker]

This thread is turning into a great "check this first" guide.

[lukier]

SRS SR850 lock in amplifier. It was thrown away because half of the CRT screen was black and unreadable. Someone even wrote on the case "GPIB ONLY IN PRINCIPLE". I had to bend some metalwork, but this I suspect was the damage caused by the workers chucking this boat anchor into the dumpster. The real problem (CRT image) was just soot and fine dust collecting on the acrylic in front of the CRT tube, as the high voltage in proximity likes to attract such dirt. Some cleaning and SR850 is good as new, well within spec (under 6 nV/sqrt(Hz) input noise).

Also few E3631A. One had faulty 30K ADC resistors (mentioned by free_electron somewhere here), another one just grease in the rotary encoder and the third one took the longest to debug - faulty SRAM causing the CPU to crash.

That's pretty much it from the dumpster. On eBay I once picked TTI TG1010A for 35 GBP. It needed a replacement battery (non critical, just waveform storage & settings) and had a cold solder joint on one of the SOT-23 transistors (AFAIR) used in row/column matrix switching for the keypad (the first column of buttons didn't work).

Surprising amount of eBay "for parts or non working" purchases turn out to be perfectly fine. I'm not TheSignalPath, I cannot afford to risk $500 on something broken (well, I cannot afford $500 on anything most of the time anyway), so these are rather really bottom of the range scores, $30-$50 most of the time with few exceptions in the $100-$150 range where I had some gut feeling (or judging from the photos) that the thing is OK or fixable.

[BMack]

Plasma TV - one of the huge ones which required several people to move it.  Customer said it had no sound - everything else worked.
Not exactly keen to dismantle or even move the thing, so first shoved some audio into one of the many inputs - sound blared out at full volume.

The problem was that the customer only used it with the HDMI input, and that had a menu option to disable the sound so that an external sound system could be used instead.  A few presses of the remote control, and the 'fault' was fixed.

I thought you were going to say the TV had external speakers, I've gotten that a few times. It's hard for a TV to have sound output when it's missing the speakers.

[matt6ft9]

A couple of days ago, I noticed one of my Airlink IP camera's was not showing up on the network and had an amber LED that would flicker about every second.  Normally, the LED would be off.  After a short investigation, the 5V, 2.5A wall pack had crapped out.  The walpack was replaced and the IP camera is happy now.
-always check the wallpack-

[VK5RC]

One of the saddest things is , as I read with interest all the "quick" solutions to problems,  I have had a good proportion of them but quite a lot took me WAY TOO long to find. FFS

[Gyro]

My easiest one was probably the Toshiba laptop that I bought from an office equipment auction (a proper auction, not ebay). It was a TFT display one, this was in the days when STN was common for the color ones. Anyway it was listed as display not working and I got it really cheap. I got it home removed the bezel and plugged in the display connector and it worked perfectly.

It was a proper connector not a flexiprint so there's no way it could have slipped out. I can only think that someone in the office had thought they'd try to bag themselves a free laptop from the bin but the company sent it off to auction instead! 

[HighVoltage]

Plenty of easy repairs.

Bought a scope "not working" ----> PSU cable was off

But most easy:
an expensive industrial WAP vacuum cleaner was given to me with the comment: This one "sucks" (pun intended) because it does not work and obviously did not suck any dirt.
Well, as unreal as it sounds, the bag was full!

 

[CJay]

One of the saddest things is , as I read with interest all the "quick" solutions to problems,  I have had a good proportion of them but quite a lot took me WAY TOO long to find. FFS

Definitely, I reckon we would all have been caught out by them on more than one occasion.

Go check out the BEC test thread and the video of Dave trying to repair a controller on a quadcopter for a prime example of a lesson I've learned the hard way too.

[bitseeker]

as unreal as it sounds, the bag was full!

Fantastic!

[bdix]

Tektronix 576 curve tracer. The Readouts were gone. A replacement had already been ordered. Appears someone had turned the readout intensity all the way down. Just turned it back up.

[SeanB]

Plenty of easy repairs.

Bought a scope "not working" ----> PSU cable was off

But most easy:
an expensive industrial WAP vacuum cleaner was given to me with the comment: This one "sucks" (pun intended) because it does not work and obviously did not suck any dirt.
Well, as unreal as it sounds, the bag was full!

Funny enough, a Hoover branded bagless cyclone cleaner, which was full of dust, and where the cyclone was packed solid with dust and carpet fur as well.  The flat pleated filter was a flat surface on the inlet side from dust. A few wash cycles and some digging out of the kilo of felting inside the housing, and a good drying and it now sucks quite well, though it is incredibly noisy, compared to the other canister vacuums I have.

Another was a Hoover upright, which was not sucking. Needed a new belt for the brush, which was slipping and thus not turning the brush, plus a little work with some PVC sheet to make a new cover for said belt, as this is also the suction inlet. Not going to pick up much with no brush rotation and with all the suction coming from a small spot at the back on the one side. Had to shorten the inlet hose slightly as the cleaners had bent it ( how, when it has a nice tray to hold it) and crushed the end.

[guido]

Fluke 335D voltage standard. On the back there are two fuses. One is low current and the other one high current. The low current fuse instantly went bang at power up. Took me only a moment to find that somebody swapped the fuses. Put the higher current fuse in the correct holder, put in a new lower amps fuse and it worked. 

[GreyWoolfe]

Tektronix 576 curve tracer. The Readouts were gone. A replacement had already been ordered. Appears someone had turned the readout intensity all the way down. Just turned it back up.

I actually did that to the monitors of a pair of cranky old ladies at a job I had many years ago.  Very funny watching them go crazy trying to figure out what was going on.

[CJay]

Funny enough, a Hoover branded bagless cyclone cleaner, which was full of dust, and where the cyclone was packed solid with dust and carpet fur as well.  The flat pleated filter was a flat surface on the inlet side from dust. A few wash cycles and some digging out of the kilo of felting inside the housing, and a good drying and it now sucks quite well, though it is incredibly noisy, compared to the other canister vacuums I have.

Possibly noisy because the motor may be damaged, when there's lower air pressure the motor will overspeed and may damage bearings if left for any length of time.

[TimFox]

I have done quite a few repairs on instruments from the days of real rotary switches, where the only work needed was to clean thoroughly the switch contacts with contact spray (I now use Gold-X).  This was true for a few vacuum-tube units as well as solid-state units.

[oldway]

I know I will make some jealous! 

I bought in a flea market a not working Marantz 2285B for parts for 35 euros.

Examining the receiver, everything seemed in order, no burnt components, no blown fuses, almost new.

I powered it progressively on with a variac and everything was ok.
It was working. 

The problem ?
All dial lamps were dead, giving the impression that he did not power on. 

[Wytnucls]

My newly acquired Fluke 867B had a strange behavior on the component test selection. It would sometime cycle through a couple of correct screens then go blank. Applying pressure to the meter face, seemed to recover functionality.
Opened it up, followed traces routing away from the front selector switch to stumble on a capacitor which didn't look right (between selector and PCB screw). There was hardly any solder on one side of it. Reflowed it with extra solder and Bob's your uncle, problem solved. 5 minute job. I wish it was always this simple.

[NivagSwerdna]

I once bought a new but faulty guitar amp...

I unscrewed the box, found the speaker leads were hanging, never connected.  Attached them, closed up the box and had a nice guitar amp.

 

[bitseeker]

All dial lamps were dead, giving the impression that he did not power on. 

Nice one. As always, "Know thy equipment." Or, failing that, "Read thy manual."