[Closed] learning to solder?

Most PCBs have components surface mounted so you stand little to no chance of extracting and/or replacing individual components (even if you could detect which ones actually need replacing). Most boards are just replaced as a complete unit.

But...if you can isolate the faulty component and you think you can replace:

1) Don't use too much solder!
2) You need to get a nice flow of solder from the soldering iron onto the leg of the component.
3) Overheating the component will destroy it.

It's a fine art and I'm no expert - but practice makes perfect!

Doesn't look like a SMT board though - and I think he's identified the faulty component already? As the board is a bit blackened I'd go with an electrolytic cap that's gone short, so you could measure with a DVM. Boards are replaced as a unit because labour isn't cost effective in this country. SMT components are generally easier to remove than thru-hole, as you can swipe them off, wick the pads flat then replace. To be fair, I do have a lot of experience so maybe I think it's easier than it looks. Totally agree with lead-free solder being an arse mind. And because the irons were consuming more power not a net environmental benefit either 🙁

i'm starting to learn to solder myself, although i've got myself a quad 303 amp to play with not a washing machine ; )

this is the desolder bargain of the year...

http://www.maplin.co.uk/p/white-box-de-solder-pump-n91ll

and this is a bit of a gem too...

http://www.maplin.co.uk/p/the-art-of-soldering-cj23a

after much looking and reading i bought an antex XS25 and a couple of extra tips of varying sizes, about 20quid delivered i think after shopping about. tips from ebay. but i can already see that if i get very keen i may well go looking for a nice used soldering station set up.

i need a stand now as well and funnily enough had just come across the metal sponge things myself so reckon thats what i will buy. cleaning the tip and keeping an eye on the tinning makes heaps of difference, i never knew to do that before.

for practice there are little diy kits full of parts on ebay for about 99p from china. i bought a mono amplifier to work on soldering and desoldering.

related but not specifically soldering, i also read electronics for dummies last winter. search on google and you will find earlier versions on pdf. i liked it and now intend to buy the latest expanded version for reference and to work through the projects in there.

then i'll set to on the quad... what can possibly go wrong!

I bought the aj55 from maplin.

Heats up in 30 seconds.

I need more heat than a 28w could provide as it seems I'm often soldering late at night outside in the sub zero.

I had to buy a new one after my cheapo wouldn't melt solder to let me repair my fog light switch at 1am the night before mot 🙁 ended up using a mapp torch on low to repair it.

Oh and like the idea of diy kits for practice.

I'll go have a look as my soldering could use practice. Been 15 years since I learnt and since then the extent has been jointing wires.

This thread has made me think about projects again. I fancy building a bass guitar amp.

Sorry, didn't read through the entire thread. If you suspect a cap has blown (which you can easily spot as they tend to "bloat") you can snip from the top of board, heat gently, and push through revealing the empty holes. Remember to observe polarity before you remove and replace.

this is the desolder bargain of the year...

after much looking and reading i bought an antex XS25

I have that XS25 iron. It's seems okay to me (light electronics work) - it does struggle a little on things with lots of metal or heat sinks on them though and the plasticy lead is really bloody annoying (apparently there is a version with a silicon lead that is meant to be much better).

If you are looking for electronic components rather than whole kits then I can recommend this eBay UK seller:
http://stores.ebay.co.uk/abxlabs/
Nice guy. Met him at Maker Faire UK (which is an event I highly recommend everyone on this thread goes to!)

Here's a nice little learn to solder video from Carrie Anne of Raspberry Pi fame:
https://www.raspberrypi.org/blog/learn-to-solder-with-carrie-anne/

Interestingly she was taught by someone called "Gert" - anything you want to tell us there gerti? 😀

Op

I've not read all the posts here but just wanted to check you're not doing any of the psu caps are you? or poking around that part of the appliance etc?

I'm only asking because you probably (by virtue of not being able to solder or identify the faulty component through visual means or using a mm) may not be aware that the psu section of an appliance needs to be treated with care.
I know **** all about washing machines but know psu's well. If there is an issue with the bleed cct it is conceivable there's enough charge stored in the caps (dependant on its design) that will at best give you a entertainingly good shock or at worst kill you. It is rare for the latter scenario but it is a possibility so thought it might be something worth bringing to your attention as a novice tinkerer..

Fair point. If it is a decent size cap then it's always a good idea to short across the terminals with an insulated screwdriver... I mean "a certified capacitive discharge device" 😉

got a washing machine playing up, and been looking online for solutions. seems to be a well-known fault with circuit board, replace capacitor C17 etc etc. i always try and fix things myself if poss, both for money saving and learning something new, so im looking at trying a 50p fix rather than a new washer.

Is this the flashing lights on the front of the machine scenario?

I changed the capacitor on mine a few months ago. All working fine. Solder sucker is the way to go.

Not that it really matters but I own a PCB assembly company and shown this to our senior assembly engineer.... He's not normally a sweary bloke!!

Do tell, I used to work in PCB assembly for defence electronics and radar companies, eventually was a production manager for a sub contract company...

Show us a pic of the cap and the other side of the pcb 🙂

Snip the legs of the old cap leaving a bit sticking up, solder new legs to old stubs, shorten the new legs first if space an issue.

Is this the flashing lights on the front of the machine scenario?

questions about whether im sure ive got right capacitor/board/other things i dont understand 🙂

Show us a pic of the cap and the other side of the pcb

[img] [/img]

underside of board.....

[img] [/img]

thanks

Bottom nuggets - joke's already been done.

😳

pic of cap, top right of the cluster of 4 at C17. and yes, it is slightly domed.

Yep that cap has had it.
Swollen up nicely and looks like a bit of electrolytic fluid might have already leaked out.

You can see that the polarity is marked (with a '+' on the board and the negative stripe on the capacitor).

update. decided that the stuff i bought from maplins isnt good enough for me as a beginner and its certainly not doing what i want it to with a circuit board so its a waste of money. took it back to maplins and got a refund.

gambled on taking the board to the one place in town that does this sort of thing, but lost the gamble when they said the bloke that solders retired 10 years ago.

so now i have no equipment, still got a dodgy PCB and a wife who's crying out for the washing machine 😀

ill have to ask around a few mates, see if anyone does it locally.

thanks

This guy is always good for a giggle while being very informative

A good section particularly of interest to trail rat at around 11 min in

I'd say post it to me and I'll do it, but I'm away on wed eve and not back till Jan so you'll have to be quick!

good news. took it to a mate, again we struggled to melt the solder on the board but got there in the end with a 2 pronged heavy duty type iron, and put a couple of blobs on a new capacitor.

looked a bit scruffy and didnt know if id ruined the board with all the prolonged heat from failed attempts but...... put it all back together and it appears to have worked 😀

so, ive learned something along the way, mainly that solderings a bit harder than i would have expected, and cheap equipment is basically not up to the job.

thanks for your help

Glad you got it sorted. And a new skill half learned.

Stick at it. It's kinda fun, but a bit of a rabbit hole (I'm just learning myself after decades of writing embedded software with very little idea what the electronics side was doing).

yep ulysse thats what i was getting at - my cheap 28w iron in the cold working on wire couldnt heat the work piece up enough due to a lack of heat.

it was very hot prior to starting work but soon as i touched the work piece ....death.

MY new one - at a significant number x more of a cost after rusty mac of this parish who does these things for working and thus knows more than i .... recomended i buy this item which is still not mega bucks as far as solder irons go i see but still significantly better .... deore/slx vs supermarket megashift sorta level ... ie one works and the other does stuff but not what its supposed to 😀

I highly recommend a gas powered soldering iron kit for the hobbist, less risk of overcooking components and will come with different shape n sized tips making the job a lot easier.