Don't you hate it when - Page 1
Forum section: electronics / general

author: KJDS
author_rank: Super Contributor
timestamp: February 22, 2015, 02:42:23 pm
content: I've just tested a power supply and it had a minor fault. This dual power supply has a current limit and when the output is switched off then the current display shows what the limit is set to. One half is fine and the other displays 0.00 when off. Both sides are fine when turned on, showing the correct current and are properly current limiting when adjusted.So I hunt for the service manual, curse a little as the description and schematics don't match. Take the power supply apart, spent half an hour getting at the screws to free up the main boards so I can probe both at the same time to help find the fault. I turn it on to start the fault finding and it now works fine. I've wiggled and prodded everything, made sure nothing is getting hot, inspected all the joints which all look great and can't get it to go wrong again.I hate that

author: Mechanical Menace
author_rank: Super Contributor
timestamp: February 22, 2015, 03:06:33 pm
content: And give it a couple of weeks it'll develop the same fault, and when you come to fix it it fixes itself againI hate none reproducible bugs

author: Fsck
author_rank: Super Contributor
timestamp: February 22, 2015, 03:13:53 pm
content: isn't it even better when it doesn't work correctly for other people but everything works fine for you?

author: Mechanical Menace
author_rank: Super Contributor
timestamp: February 22, 2015, 03:19:10 pm
content: Quote from: Fsck on February 22, 2015, 03:13:53 pmNo, just no.

author: wraper
author_rank: Unknown
timestamp: February 22, 2015, 03:51:18 pm
content: Quote from: Fsck on February 22, 2015, 03:13:53 pmYeah, like when customer brings his device to the warranty repair fifth time and receives it back with no fault find once again.

author: GreyWoolfe
author_rank: Unknown
timestamp: February 22, 2015, 11:47:39 pm
content: Quote from: Fsck on February 22, 2015, 03:13:53 pmHappens all the time with SWMBO and stepdaughter's laptopsCome to think of it, happens with my sites also. Service call comes in too late in the day to get there, get there the next morning and all works fine.Real pain if it is an hour and a half to the site.Customer swears up and down that there was a problem and I can find the problem in the server logs. Overnight Murphy comes in and fixes things for me.

author: tautech
author_rank: Super Contributor
timestamp: February 22, 2015, 11:59:51 pm
content: Don't you just.Customer rings with a fault on the little 30V 5A SMPS I supplied.Get it on the bench, put a good load on it, check readouts for accuracy, ripple and smart fan cycling....perfect. CC mode was on.But becauseMurphy is always watching, I decide it best to send my personal unit as a replacement.Like to know where this Murphy guy lives, got some stern words for him.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: February 23, 2015, 12:27:44 am
content: Quote from: tautech on February 22, 2015, 11:59:51 pmFor me Murphy is always hiding behind "you know this shit, well..."

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 23, 2015, 12:29:53 am
content: "Don't you hate it when..."...Threads don't begin with descriptive titles?Tim

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: February 23, 2015, 06:05:55 pm
content: I hate it when I throughouly test something, pot it with hot snot, and then I have to get it apart because something doesnt work, or I need to make a change. I also hate it when I get to the last screw on something massive and it strips out. Someone definately looses their breathing priviledges lol

author: Ampera
author_rank: Super Contributor
timestamp: February 23, 2015, 06:11:28 pm
content: I had an IBM PS1 consultant that wasn't booting.Left it on the desk for 2 weeks, turned it on and it is fine.Same with my IBM E-Severs.Not that I'm complaining....

author: KJDS
author_rank: Super Contributor
timestamp: February 24, 2015, 05:54:04 pm
content: and another thing I hate.I've just found a dead bridge rectifier in a circuit. Only a little one, can't be more than 1A and I know it's only supplying about 10mA. I don't have one that will fit, but I do have some 1N4004 which I can make a bridge from.Unfortunately one of the diodes in the bag is marked up the wrong way. I now need to buy a new fuse.

author: Dinsdale
author_rank: Regular Contributor
timestamp: February 25, 2015, 12:04:10 am
content: QuoteYou're a genius. Did you ever think of that?

author: Stupid Beard
author_rank: Regular Contributor
timestamp: February 25, 2015, 12:31:42 am
content: At the weekend I decided I should get around to building an electronic dummy load, so I ordered the parts I was didn't already have.In the process I spent a lot of time making fun of Farnell's parametric search for counting "Awaiting delivery" as "In stock" when their expected delivery dates were multiple months in the future.Somehow in the process, I failed to notice that out of the two choices of 10? resistors, I chose to order 50 of the ones they only had 39 in stock of. So I placed the order and got a mail saying they'd send 11 of the damn things and will send them roughly around the 25th of MayEven better is they only had 9 left in their UK warehouse. So they split shipped 9 from the UK and 30 from Belgium. Both deliveries should have been here today. I should in fact now have the dummy load finished.However, I dont. UPS, being utterly shit and unreliable, decided to not bother to even try and deliver one of the orders today but instead show it as out for delivery for the whole day.The one order they did deliver was the one that had the 9 resistors. So I'm 1 short.I also still have no idea where the second order is, because UPS' tracking still showed it as out for delivery right up til midnight when it changed to In Transit without any updated scan. So I've totally wasted an entire day staring out the f'ing window and getting little of anything done.UPS do this crap so often that it's like Delivery Roulette.Oh, and I had a project box I had laying around from many years ago that I was going to use for it. I thought I knew exactly where it was. I of course can't find the bloody thing anywhere now that I need it.

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: March 02, 2015, 03:24:49 am
content: Quote from: Stupid Beard on February 25, 2015, 12:31:42 amHave you seen mikeselectricstuff's bucket dummy load? It is just a bunch of enamled wire in a bucket of water. It an awesomely simple solution to a problem.

author: Stupid Beard
author_rank: Regular Contributor
timestamp: March 02, 2015, 03:36:15 am
content: Quote from: iamdarkyoshi on March 02, 2015, 03:24:49 amNo, but that's hilarious. If I had some enameled wire or suitable substitute I'd do that just for a laugh

author: Fsck
author_rank: Super Contributor
timestamp: March 02, 2015, 03:44:41 am
content: so this just happened. how about when you take something apart, only to put it back together with a few screws left over?