Anyone in here interested in electronics

There are plenty 'interested' here, but that is well vague!

Suggest you either put the list here, or put the lot up on eBay. Don't expect much for it though.

J^n

Ok, this is the list of components I have:

Component list IC’s TRANSISTORS LM3914 x3 2N2222 x7 LM3915 x3 2N3904 x8 LM3916 x3 BC547 x8 LM339 x5 BC548 x8 LM386 x4 BC337 x10 LM741 x2 2N3906 x8 LM1458 x2 BC557 x5 LM324 x5 BC327 x12 LM358 x8 TIP31C x5 LM4562 x1 IRLZ34N x8

Elecrolytic Capacicors

I would ebay them and make a few pennies.

Sometimes parts for old equipment no longer made fetch a high price. You cant get an R53 thermistor for love nor money.

I've some high voltage switching transistors - about 80p back in the day

- that go on ebay for £15...

Bu you could publish the list here.

You simply never can tell rare parts needed to service old equipment fetch a premium.

ICs will make tens of pennies each as will the transistors.

I wouldn't touch the electrolytics with a bargepole.

Sell the ceramics and resistors as bargain bundles.

You might make a couple of hundred in all.

I'd be more interested in e.g. a Weller solderiing iron or a variable power supply...

I have a Evantek variable PSU I bought 2 years ago. it's 0-30v , 0-5A if you are interested

Absolutely I am

E-mail t n p @ s h a m a n . c o . u k

Agreed

Agreed

I'd be amazed if you got that much ... but you never know. And they are likely to take a long time to sell.

I sold a Weller soldering iron on eBay a few years ago, and confess to slightly regretting it. They do still come in useful sometimes, even though I also have a more modern one (as well as my dad's 65W Solon iron, more of a plumbing tool than anything...)

J^n

I still use my old FEC TOPS-3 ... but I imagine these newer PSUs have a better spec / are cheaper than such a 'vintage' item?

('Ev*e*ntek' I think, BTW)

Email sent

Some of them can be, but it really depends on whether they're unobtainium at Farnell and friends. If not they're often pennies for brand new parts.

There's nothing on that list that strikes me as particularly rare ICs, but I don't have the full 74xx and 4xxx series catalogue in my head so maybe there are a few.

OTOH I assume they're in DIL and maybe some chips are only available in surface mount nowadays. Or somebody really needs a 74xx not a 74HCxx.

Theo

Lots of DIL available on old parts for spares.

Interesting video from Adrians Digital Basement a while ago where he couldn't get an old terminal working, and it turned out that there was a race condition in the hardware that was solved by installing a higher speed part than the original..

I try not to work with anything less than DIL because my eyes can't handle it. And I don't have tremble free fingers or a hot air station.

I have used them and do use them because I have them, but I wouldn't buy them.

I am right now awaiting delivery of a hot air desoldering station, cheapish from eBay, because I need to desolder and replace some SOICs. I've seen it all done plenty of times but have never done it myself. I have an old laptop motherboard to practice on...

Sell them as a joblot on *bay.

Best of luck. I'd be interested to hear how it goes.

This is actually the SOIC footprint, i.e. 1/20 inch spacing? My recommendation is to cut the leads, remove individually with normal iron and tweezers, clean pcb with desolder braid, add rework flux to pads, drop IC on, resolder with iron. Start with two corner pins, then once the position is right, fill in the rest.

You say you haven't done it before with hot air, I've done it a few times and I'm not at all confident of doing so without damage to the rest of the board, depending of course on component density and track width. It will take more heat than you expect to get all pins molten simultaneously, though with a SOIC you can do one side at a time.

These days I mainly use my hot air station for heatshrink, and occasionally reworking hot melt glue.

The trick is apparently to use shields all over the place - Kapton tape plus anything that will stand the heat so that on;y what you are dealing with is affected

Argh, Re melting hot glue!. Heatshrink yes.

But getting the pads hot enough to melt solder also softens the glue that holds the pads down, wherever else the heat may go. All of the solder on every pin has to be really completely melted to have a chance of lifting the IC without lifting any pads. Many tracks are hair-thin. I will always cut pins if I can.

Another technique is to mop up as much solder as possible with braid, then hook very sharp tweezers under one pin at a time and use an iron to melt just that pin. Slow, but sometimes the braid will remove enough solder that fairly gentle lifting with the tweezers will break the remaining solder, while the pad remains cold. If the pins weren't laid flat down on the pads during manufacture, this is not too difficult.

It shouldnt. They should be epoxy bonded with high temperature epoxy.

Ive only had trouble on cheap phenolic resin (paxolin) 'bread' boards which are junk.

Remember that surface mount boards have been DESIGNED to take the heat. And flux and lead solder will lower the melting point of the original solder as well

Most semiconductors will take 180°C inside before the silicon is damaged.

Most solder melts at or before that ...

All works until you have to remove something that has pins underneath it