A random capacitor just dropped from the laptop I was repairing...

Thread Starter

rambomhtri

Joined Nov 9, 2015
346
Hi, I was repairing this slim 360º laptop that was overheating and having some software issues, and once I checked everything that was wrong (I turned it on to do so) I turned it off and proceeded to clean and disassemble the insides. Same thing, done it thousands of times, deep clean, new compound, fan clean... when I am putting it together I notice a little sound rattling inside. I just had closed the last bottom lid. I opened it, on the table, and BOOM, a random tiny cap (thanks God I noticed it...) appeared right in front of me. My heart stopped beating. I knew that was a freaking cap that just got unsoldered for no reason off the board...

WHAT IN HEAVENS?!

I immediately contacted the client telling him I don't know how and what happened but a random electronic piece dropped from your notebook, from the board. I'm really shocked. I don't know what in heavens is this, but it's so weird. Pieces don't unsolder like that, never ever seen anything like that, and I have easily worked on... 100 notebooks? May be more.

So I started to check for a semi soldered "hole", but there were like dozens of spots that were fitting the cap. I was about to gave up, I knew something really bad would happen and I was right, it was not turning on at all. Huge mess, bad rep, least luck of the year. It was not really my fault, at all, but the client is going to apply the "you touch it you own it" philosophy, as pretty much every ignorant (sorry but it's what it is) client would do.

Almost abandoned all kind hope as I don't have at all the ability, skills and knowledge to solve this kind of puzzle, but suddenly I notice in one corner a little bit of solder in both sides of what appears to be a spot for the cap. I recheck it, it really looks like it was there, I solder it, and BOOM!, it turns on.

Made my day, that moment, amazing.

Basically I open this thread to share this little piece of heart stopping story, and to know if something like that happened to you, and mostly, how would you act in these cases, what would you do. I've never really had these kind of problems, the huge fail of receiving something faulty but that was working more or less fine, and mess it up way, way more than the original state. I do have received some things that I could not repair but that was OK, thought never something to repair this area or that and suddenly completely wreck the item. I still don't know how to react to that, and I think about that moment every day, and it's gonna come sooner or later, and it's gonna be a very bad day.

Also, how can you defend yourself from the "you touch it you own it"?
Meaning, if something breaks and you didn't have anything to do with it, but the client is going to see "ok, I gave him a working PS4 (for example) and now it's not turning on, so he must have messed something".
 

wayneh

Joined Sep 9, 2010
17,031
Also, how can you defend yourself from the "you touch it you own it"?
Meaning, if something breaks and you didn't have anything to do with it, but the client is going to see "ok, I gave him a working PS4 (for example) and now it's not turning on, so he must have messed something".
I really don’t think you can. The (low?) risk of that happening is an unavoidable overhead cost.

You COULD manage customer expectations by demanding they agree beforehand that an attempted repair might fail, and that you will NOT be held responsible. But frankly I think it would be better for business to just absorb the risk and hope customers talk about you being the ultimate fix-everything guy.

Only you can really judge which business practice is better for you in the long run.
 

Yaakov

Joined Jan 27, 2019
2,381
Long ago, when an IBM PC XT clone was a thing people wanted, I wanted an upgrade to a blazing fast 12MHz PC AT clone so to fund this I took my XT motherboard and some parts and cobbled together an XT to sell to a friend.

I needed two things: a floppy drive and a power supply. So, I went to Eli's in Cambridge near MIT and bright a used floppy and power supply. He guaranteed me the PS was working, it was a pull from something. I went home and put it together.

Flipping the big red switch I heard a terrible popping sound and smelled magic smoke. Checking the motherboard I found that every tantalum bypass cap on the 12V rail was gone leaving only a skid mark to show has once been there.

Talk about panic! I'd already spent the money on my new AT parts and I had no way of getting a new motherboard or refunding the friend! I dug through my parts and found some caps that should work. I replaced all the caps, I think 6 or 8 of them, through hole, thankfully. I put in the known good supply from my new computer and... it booted! Except the floppy didn't work.

Pulling it out I found on the bottom the motor controller chip had a crater in it where the die used to live. Checking the output voltage on the PS there was 18V on the 12V line, sheesh.

I took the two parts back to Eli and he replaced them.

For months after that, every time I flipped a big red switch I heard a pop and switched it off again. PTSD, I suppose.
 

andrewmm

Joined Feb 25, 2011
1,131
Out of interest,
look carefully at the capacitor,
does it have some of the Pad from the PCB with it ?

I've certainly knocked off a part or two in my time,
 

Thread Starter

rambomhtri

Joined Nov 9, 2015
346
Out of interest,
look carefully at the capacitor,
does it have some of the Pad from the PCB with it ?

I've certainly knocked off a part or two in my time,
It didn't have the whole pad, not at all. It DID have the solder marks/shape that fit the spot I saw. It's simply that I was looking brainless for a space that was used or something, and I found it, 2 rectangular pads that had a little bit of solder each, and I thought: that must be it. I really couldn't believe it because I was sure I was doomed. No way I find that random spot. Well I did, hahaha.

I once saw a pad completely lose, it was soldered/stuck to the component, not the motherboard, huge fail. It was in an expensive audio device, there was a 90 degree jack connected to the device, it fell to the ground, knocked the jack perfectly in the center, and all the force of the falling went through the 4 surface mounted jack female solder joints. It of course ripped all the four legs off the board, leaving the surface mounted jack female lose and with all the 4 pads of the board still soldered nicely to the jack. I tried to repair it but it was impossible. By that time (7-8 years ago) I wasn't that experienced soldering all kind of stuff and my skills couldn't do anything.

1617711930904.png

Now, with my experience, I would try to find the path of each leg, solder and auxiliary cable to each leg and join it to the other end of the path, and the really difficult thing would be to make sure it stays where it was, solid and firmly stuck, but without any kind of solder to support. I would probably hot glue it to the board all around once I've soldered everything. I don't know how much it would stay there, since these female jacks are abused by the users that pull and plug the headphones recklessly.
 
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