Hi. My name is*****'m a camera repair technician with over 20 years in the business and I'll be glad to help you with your question today.
Error code "99" is a general error code that simply means something is
wrong. The camera does store specific internal error codes but it takes special software available only to Canon repair shops to read them.
The problem you are experiencing is usually caused by a damaged or defective flexible ribbon cable that connects the diaphram unit to the lenses circuit board. These are designed to flex with the lens as it extends. However, they do have a limit and will crack and break eventually needing to be replaced.
This really isn’t a user serviceable problem and should be repaired by a qualified technician. You may want to check locally for a camera repair shop in your area, or, if you need assistance finding a shop, please let me know and I'll locate one for you.
The website link for Tamron service in the UK is :
thanks for that. From your past experience can you tell what I should be expecting to pay for this repair. Are there any shops left that do their own repairs in or near Alnwick, Northumberland. Should I consider the purchase of a second hand replacement.
Repair costs will vary from shop to shop and are usually most expensive when done by the factory. As far as the cost of the repair, you'll need to contact a few shops for estimates. Below is a link to a directory of repair shops, one of which should be in your area and able to help you.