Soldering a chip into an ECU

[adam73bgt]

I've got a chip for my RX7's ECU which I need to fit as I need the car mobile so I can move house

I've done a bit of soldering in my time but probably not with anything as valuable as an ECU...

So my question is, as a DIY'er, how easily will it be to cock it up? It's desoldering a chip, then soldering a socket in its place, and the new chip is actually just pushed in

Is it something I should get someone else to do?

Any advice is very appreciated!

[VW]

You will need a solder sucker or wick to remove the solder on the chips legs.
don't over heat the tracks or they might lift.
Trying to remove the chip without removing the solder might damage the tracks.

Same when soldering back in.

If you can solder competantly and have a good iron with a fine tip you'll be fine.

The most important thing will be removing the solder fully and quickly.

[Clamity]

If it's thru hole (legs poke through holes in the board), clip them off the old chip first and desolder them one by one. You're way less likely to damage the board that way.

Obv. don't do this if you want to keep the old chip.

[ChasR]

If you need to borrow a good iron let me know. I have (well, I mean my dad's that I seem to have acquired) has a Weller iron from around 30 years ago. It's been a faithful old thing!

[Deleted]

One thing normally overlooked is static. Static fries EPROMs. If you have ever bought any new components,you will have noticed they often come in foil and plastic antistatic bags . Best done standing on a tiled floor after you have earthed yourself out by touching something with a good earth,i.e. The kitchen sink.....

[MiataMark]

Oct 26, 2016 3:54:55 GMT @johnnybravo said:

One thing normally overlooked is static. Static fries EPROMs. If you have ever bought any new components,you will have noticed they often come in foil and plastic antistatic bags . Best done standing on a tiled floor after you have earthed yourself out by touching something with a good earth,i.e. The kitchen sink.....

Good point, to be doubly safe use an earth strap, a wire connected to an earth (radiator etc) and your body.

[adam73bgt]

Cheers for the replies guys, I've got a semi decent iron and a plunger/sucker thing, so I think I will have a go

Oct 26, 2016 3:54:55 GMT @johnnybravo said:

One thing normally overlooked is static. Static fries EPROMs. If you have ever bought any new components,you will have noticed they often come in foil and plastic antistatic bags . Best done standing on a tiled floor after you have earthed yourself out by touching something with a good earth,i.e. The kitchen sink.....

Good shout (except my kitchen sink is plastic... ) I think I've got an anti static wristband somewhere from when I built my PC so could chuck that on if I find it, otherwise I'll ground myself via a radiator or something

[Deleted]

Jumper cables work well. Red on the hot tap, black on the cold and clip onto earllugs....

[Soopahfly]

The key is to not keep the heat on for too long. If you have an adjustable temperature soldering iron then great.
Don't bother with suckers, use a desoldering braid, a good one with flux and it will suck the solder straight off the board and leave it nice and clean.
Use flux on the socket and the chip legs and it should be simple enough.

Will you be needing to change the chip again in future? If you are, it's worth soldering on a socket instead.

[skkylinedave]

If you have doubts i would see if you can find a local electrical repair place , tvs , white goods etc . I have got stuff done by my local one [ resistor in a welder ] and he charged me £5 .

[rbs]

I usually earth myself into the mains. Wire a 13A plug with just the earth pin, attach the wire to your wrist and plug it in.

[sausage]

Get you hands on some scrap electronics with similar chips you intend to desolder etc and practice on that 1st.

Post a pic of what you are talking about desoldering and installing too would help.

[welshpug]

Oct 28, 2016 19:56:41 GMT rbs said:

I usually earth myself into the mains. Wire a 13A plug with just the earth pin, attach the wire to your wrist and plug it in.

not advisable, if anything else in the house goes to ground you'll become part of the circuit yourself.

it is not a pleasant experience!

[rbs]

That's what BMW have us do. They supplied us with an anti static matt, a 13A plug with a velcro strap and connector for your wrist and another wire to clip onto the matt.

[sausage]

Like this?: www.rx7club.com/2nd-generation-specific-1986-1992-17/stock-ecu-real-time-tuning-datalogging-1065541/page2/

No problem with big chips like that, but you have to have the right temperature iron otherwise too cold and you stick the wick and can lift and tear pads and traces, too hot for too long and you can burn the pads, best to add some fresh solder to it and then desolder as the new solder will help the old stuff melt and wick away much better I've found as the factories sometimes use quite a hard solder.

[adam73bgt]

Aye very similar sausage , I've not had a chance to pull the ECU out the car just yet, but heres a couple of pics from the installation instructions

[bmw2101]

Id cut the legs with knife, and pull them out one by one. You can then use a wick to clean off the old "sodder..."


The old sodder maybe lead free, so either " suck it off " or wich it off before you put the new chip in...

[adam73bgt]

Thank you for all the replies and advice, I took the ECU out the car today and had a go.

I cut the legs off to remove the old chip, then used the soldering iron with the plunger/sucker and a small pair of pliers to remove the remnants of solder/wire

Then soldered in the socket and the chip pushed in, went pretty smoothly!










Thanks again all