I’m a buffoon

[KimB]

My luck these last couple weeks has been bad! Today I made it worse!

So my defender broke down yesterday which was fun. The immobiliser packed up and I couldn’t lock or unlock on the fob. I was at the shop when this happened.

Annoyingly the fob is needed to turn the immobiliser off, but because the 10AS module (immobiliser/alarm module) wasn’t working it was immobilesed and I was stuck unable to start it. Walked home and got my fob coding tool, then I took some electrical tools and decided to have a wiggle of the wires near the 10AS module. As soon as I did the interior light came on (this helps indicate if it’s working), I then coded the fob back to the car and it started for me to drive home.

Fast forward to today, I’ve been trying to establish where the broken wire is or if the 10AS module is faulty. Spent ages wiggling wires and testing them with my DMM, then I thought I’d try using my probe and powering the 10AS separately to see if I could work out If that was a problem. Being clumsy, I slipped with the probe, small spark and then smoke from the 10AS

In this picture you can see it’s the chip to the left of the two relays. It’s got 16 soldered joints.

The chip itself I think is this one which is also on the board.

Can this chip just be replaced? I found them online for very little but I’m concerned I’ll make it worse with my clumsiness.

Are there any companies that may do that without feeling stripped of my dignity haha.

Thanks.

 

[KimB]

This looks to be the little chip.
It's way beyond me though.

 

[pawsnizzy]

Kim,
They're a bog stock transistor array - readily available, but the surface mount soldering can be a pain if you're not familiar/geared up for it

 

[pawsnizzy]

This looks to be the little chip.
It's way beyond me though.

That chip is DIL pins, you'll need SMT

 

[pawsnizzy]

https://www.ti.com/product/ULN2003A

 

[KimB]

Kim,
They're a bog stock transistor array - readily available, but the surface mount soldering can be a pain if you're not familiar/geared up for it

Well that's reasuring. Any idea who I maybe able to get to do it?

That chip is DIL pins, you'll need SMT

This one looks like it then? like a little centipede

 

[500e]

Get the chip I can fit no problem turn round same day.
Expect @premmington can test unit as well though
Friend wont take his to Sainsburys had to be towed out 3 times soon as on road OK

 

[Maker]

Looks like a SOIC package, shouldn't be too hard to swap it out. Get some solder wick to lift the old one off and some fine solder to stick the new one back down.

 

[eLuSiVeMiTe]

Depends how good you are with an iron
Bought a rework station a while back and certainly made my life easier with smd.

That's a 3mm braid for reference

 

[Kram]

It might look difficult but theres a few techniques for soldering surface mount which makes it easy. The most fool proof is to blob solder all over and use solder wick to get the excess off, it works well provided the board has a solder mask - the green paint.

Before trying it get some practise on some old scrap boards, and theres plenty of youtubes showing how its done.

To get the old one off, I prefer to slide a fine feeler gauge under and then run the iron along each side while moving the blade to seperate pins from board. The feeler wont get hot enough for anything to stick.

 

[TechWise]

If you feel up to it, you could test the chip. If you look at the datasheet that was previously posted, you'll see that the inputs are up one side and the outputs are up the other. When 3.3 or 5V gets fed into the input, then the corresponding output gets connected to ground, completing the circuit. So the output pin should normally sit at 5V or 12V (whatever the supply happens to be)? Then when the input is turned on, the output should change to near zero.

 

[James1979]

I’ve used a guy called Martin from vantuner for similar.

However, we are overlooking mr @premmington it’s what he does I believe

 

[Barking Mat]

@ajlelectronics is the other member who jumps to mind.

 

[ChrisBailey]

Since the chip is dead, you can just cut the legs off and then lift them one by one with a solxering iron.
Put new solder on the pads then
drop new chip on and touch each leg with the iron.

 

[Seadog]

With a small, sharp, pair of cutters, snip all of the legs against the body. They then can easily be removed. It's a doddle to resolder the new chip if you have a small enough tip. Use some low melting-point solder if you have it.

 

[premmington]

I’ve used a guy called Martin from vantuner for similar.

However, we are overlooking mr @premmington it’s what he does I believe

Please overlook me - I am so busy it is unreal...

Oh... For the record I am so anti "power probe" it is unreal.

 

[dobbslc]

I've heard good things of the ECU Doctor, never had to use him though.

 

[premmington]

I've heard good things of the ECU Doctor, never had to use him though.

This is the chap from Plymouth? Yes?

 

[pawsnizzy]

Sorry I can't help Kim - I'm away from my facilities atm

 

[Wozzaaah]

Take @500e up on his offer, having a go yourself if you're not confident is a recipe for disaster.