I recently replaced the DVD-ROM drive on a Toshiba laptop.  What should have been one of the easiest repairs on a computer imaginable ended up with me actually doing this:

For some reason, known only to Toshiba (I would guess it relates to their profits), some of their laptops will not accept any slimline DVD drive that fits.  I tried several spare drives and none of them were accepted by the Toshiba BIOS.  They all gave what I now know as one of the most dreaded errors that can appear on your screen; "IDE #1 Error".

A little bit of research reveals that most DVD drives have firmware which sets them to Cable Select.  When you plug them in the BIOS tells them how to behave on the IDE channel they are on. Toshiba have decided that some of their laptops will only accept drives set to Inverse Cable Select. 

Unfortunately, there are no physical jumpers on slimline drives so there are 3 options:

1)  Find an Inverse Cable Select (Inv CSEL) firmware for your new drive, if it exists. Then flash the drive and hope you don't brick it.

2)  Open up the drive and solder a connection between pins 47 and 45 on the IDE connector.

3)  Source exactly the same drive as the one you are replacing and make sure the firmware is already known to be Inv CSEL.

I went for option 3.  The drive ended up costing £15 more than a drive without known Inv CSEL firmware but if you want to guarantee it will work that is the only option.

I hope Toshiba have stopped, or will stop, doing this.  It is a nightmare for repair guys to sort out so the general public really will struggle. Is it so that people will only buy drives from Toshiba?  I suspect it is.