[waylyn]

Fantastic thread tomalamix, my mothers car has the same problem, but it gets worse my step dad had tried to open the card but sliced through the coil several times and I can't make head or tail of how it's supposed to be wound has anyone got a pic of the winding on this coil as I look at it there are three connection points but the wire has been cut so bad that even with new wire I don't know how it's wound:forehead:

 

[SCOLEYTE]

Hello all.
Sorry I've been off scene for a while. I am soon to post to Tolamix's excellent thread and put some values to those enigmatic caps and the inductor which is very small in the order of nano Henry's. Watch this space.

 

[SCOLEYTE]

It's very easy when slicing the card open to catch these componenets so be careful. Also note that over time the card being quite flexible these components can work loose and a rattling key card can show this. Again when opening the card be careful as these components are extremely small and it's easy to loose them.
Anywaty here is some of the data.

All caps measured off board.
C2 1uF tant
C14 390pF
C13 100pF
C12 22pF
Very difficult to measure L2 - try 100nH

Still working on my card to operate doors at 433MHZ. Components are on order soon as I have soldered them in I'll post the results.
Cheers Steve

 

[dewaldLeG]

Thanks for the post. Not sure if someone solved the riddle but I can post a solution, (Insert Card or Card not detected error). I am an Electronic Engineer and could pick up where you stopped. Your observation of the resistance measurement is good. The reason as to why the “Good” remote was reading 95ohm and the faulty one 56kohm is that the coil is broken(open circuit) . The 56k ohm is the resistance of the resistor on the board and the 95ohm is that of the coil. If the coil I good, the parallel resistance will be that of the coil, and if broken (open circuit) it will be that of the resistor in parallel with the coil.

I had to unwound the entire coil, (unfortunately, it was the start of the string that was broken.)

How to Fix.
You will need.
1) Piece of Prestik glue
2) Variable speed battery drill
3) Soldering iron

Unwind the coil, very very fine wire.
Glue the plastic coil to the chuck of the drill with the Prestik.
Leave 5-10cm of wire for the start and slowly start to wind the coil to the coil holder.

When done, solder the two sides of the coil to the legs of the coils holder and re-solder back to the board.
Resistance is back to +- 95 ohm !! (90-120 pending length of coil), working fine.
Back in business, about 30 minutes of labour, savings about 150 Euro good money for 30 Minutes, I would say 

 

[ReneD]

great thread! lots of usefull info!

So nobody has found out if the coil can be ordered somewhere?

So far the info gathered here is:
125khz RFID
Air cored
2.7 mH
94 Ohm
17x3.2mm
0.75mm wire
decription on coil: 19361

Since it is a standard purchase part, it has to be available somewhere, but so far my internet search of farnell conrad rs-components has been unsuccesfull.
Should be easier to buy it somewhere is stead of re-wiring it yourself

 

[Spiky]

!

 

[Spiky]

Should be easier to buy it somewhere instead of re-wiring it yourself

That's my opinion too. This has to be the cheapest part of the whole thing. I tried to find it myself, nobody sells. Can it be in some other remotes? like TV? Why didn't Chinese copy it yet and sell it for a pound with free shipping? :d

 

[VelSatisfied]

Why didn't Chinese copy it yet and sell it for a pound with free shipping? :d

They'd probably be ashamed to charge so much...:d

 

[Djuro]

will anybody help me? i have broken capacitor on my keycard PCB and i don't know value to replace him. see picture

 

[richiedichie]

Great work, very detailed and much care been taken to describe the process piece by piece.

 

[SECPO83]

Hi every Body.(sorry for my bad english)
Only for giving you some information.
The PCF 7947AT is an OTP processor , only one shot , One Time Programming.
You can find one new on the Web but after you must progam it with a Renault Diag , putting the card in the Inlet Card reader off you car.
If you have a second card from an other car you can disolder the PCF off you own an resolder it on the second one Kepping thlike that the code of your car an make a test , normally it will be OK.
@++++secpo83

 

[curlyzoo2002]

thanks very much it took me ages to get the case open and i was a bit scared to pull it apart but i got there in the end i think if i was to do it again i would video opening the case just to show people how to do it as its a bit hard lol any ways i had 2 lose conections a we solder with some liquid solder and all was well, again thanks very much :d

 

[Jujasi]

Cheers for this Information, just repaired my card, following the first few photos as a guide of what to look for.

Much appreciated

 

[Kevin Ferguson]

Hi all, I just found this thread and have a question, there seems to be a lot of knowledgeable people on here, so hopefully someone can help or will have an idea to try.
I bought a Laguna 2 weeks ago, 2005 1.9 Diesel. I only got the one keycard when buying, but it worked correctly, locking and unlocking and also lights on and off, it is 3 button version card. After day 1 of owning, the replace battery in key car message appeared. On morning of day 2 the buttons had no effect on the locking, so I bought a new and replaced the card battery (CR2025) and it worked again for a while, a bit less reliable as originally, but then stoppped locking and unlocking and lights altogether, it will always start the car when in card reader, but the central locking side of it has stopped working as it had.
I discovered a day or 2 ago , that if i have the card inside car and point it at the card reader at about 6 to 8 inches distance, then all buttons work as they should ? So it seems to be a range problem, it will not work when any further from the car. The autolocking used to work too, but this has stopped also, I assume since the rf range has diminished , then this function has stopped too.
I had the card open (I work in the electronics industry) and retouched some joints on buttons etc. but I didnt really believe they were the problem anyhow, as the led on the card illuminates correctly when the buttons are pressed.
I can post pictures of this if needs be , if it may help ???
So i am left with this card which will start the car fine, but will not work the remote locking , unless I am 6 inches away from the reader inside, which is useless to me.
The battery in card measures 3V DC which sounds correct to me also.
Can anyone help me ? Has anyone come across as imilar problem ?
I appreciate any ideas or help I will get....
Great thread this, it seems to have helped lots of people.....

Thanks for looking.
Regards,
Kevin.

 

[SECPO83]

Hi evrybody.
My message is for people who are affraid in opening their KeyCard.
You will see that there nothing easier than that for reparing you unfonctionning Key.
You just need an Solder Iron and a shaped Blade.
You only need to warm red the blade and cut the plastic cover of you key ( red place) and after resolder the Coil pins (when the card don't start your car , not recognized) or battery pins (when card don't open doors);
To finish well the job refill with Pistol warm glue.
@+++SECPO83

 

[SECPO83]

Hi can't found how to edit my message to bring it modified so i made a knew message .
That's is for showing the Foto of what it look like when finished.
Best regards.
SECPO83

 

[chrisd]

Thank you, worked perfectly
3 days before leaving for December holiday, 3 week delivery on new Card by Renault...
The relief and appreciation is enormous

 

[craigd43]

All i can say is wow thank you so ooooo soooo much, £200+ saved your da man thanks again and again and again.:d

 

[tamscott]

Hi guys I recently sat on my last Laguna key-card and ruined it. The board is unfixable but all the components are still attached. If I purchase a Used card of of Ebay can I swap the chip from the broken card into the second hand one? If so is it just the 14 pin integrated circuit that needs swapped?

Thanks in advance,,
Tam

 

[dingodno]

Hi can you swap out the transponder to another key card if your card is broken but the transponder is fine