I bought a new key fob from the oft recommended CarKey Fob company. My nephew's wife (she has better eyesight!) helped in opening up the old key fob, and transferring the innards over to the new fob. It was a pain to get that done, virtually ripping up the old fob with pliers and sharp objects to get it open.
First problem - the new blade supplied by carkey fob company is chamfered at the top, where the plastic holding piece goes over the grub screw, whereas my original key is the same shape all the way to the top, so the plastic bit could not be stretched to fit
I decided I would solve this problem by getting the new blade cut.
I went to a Timpsons shop just before 5pm, and the lady said she could not cut the key for me, as the blade was not bought at a Timpson shop. Company policy, no doubt designed to increase profits, but kind of tough luck on you if they don't have your car type blank key or have run out... So, how much for a Timpsons' Rover 75 key fob with blade? £35. I bought the Carkey fob for under £5. So, off to another independent hardware store to get the key cut. But it was now 5 o'clock, and lo and behold, the hardware store closes at 5 sharp. They don't even have a once a week late night. About time our shopkeepers started doing like our European and African cousins, and opening until later hours so that people who work can go shopping!
Next bright idea, trim down the old key with my dremel! A much better and cheaper solution, worked just fine! New fob opens and locks the car, but the key won't start the car
I can only think that in destroying the old key fob, the transponder has been lost...? Of course, my nephew's house has a black bobbly carpet so you can't find small black objects easily. She has promised not to hoover until I say so!
So, is that my problem? Should there have been another electronic piece in the old key fob separate from the printed circuit board which I have now lost? If I can't find the original transponder, is there another solution, or am I stymied?