A4 Hard Drive Replacement

I have been having trouble for quite some time
with the Hard Drive on my A4.
The symptoms started with the drive occasonally
not booting at startup, and then not being
recognised at all, with the drive continually
seeking and poping up error messages.
Something had to be done, so I bought a second-hand
replacement drive of 63Mb from APDL and the following
shows the proceedure for striping down the A4 and
preparation of the replacement drive for use.
Click on an image to enlarge

	Tools required, from left to right; two pozidrive screwdrivers, 5mm and 3mm in diameter. A very small and cheap straight edge screwdriver with a bent end to help in lifting ribbon cable securing clips. And finally a small pair of long nose pliers.
	First job, ensure the machine has been turned off, and disconnected from any mains charger supply. Find a clean working space and remove the battery pack from the underside.
	Carefully prise up the econet module blanking plate by hand and remove. Next with the small bent screwdriver, pull up on the screen ribbon cable securing sockets locking tabs. The tabs will pop up approx 1mm to release the ribbon cables. Take care with this operation.
	On the rear of the machine, unscrew and remove the three screws highlighted with red circles in this image.
	Next turn the machine over and remove the three screws highlighted in the base of the unit. Holding the case together, turn the machine upright again and open the screen/lid as normal.
	By griping the screen sides and by gently wiggling from side to side whilst lifting upwards, the screen and rear cover/hinge assembly should come free. Lift clear and place it to the side.
	Now the delicate part. Remove the keyboard ribbon cables in the same way as the screen cables. Be careful, the keyboard cables are not as flexible and a lot easy to damage.
	When the cables are detatched, lift the keyboard unit upwards at the rear and a little bit of wriggling will be required to free the three tabs that secure the keyboard to the front of the case. Lift the unit clear, ensuring safety of the cables.
	Next we need to remove the floppy drive to be able to remove the hard drives cradle at a later stage. Lift clear the shielding plate that sits over the drive. Noteing which way round it came off! (I didn't)
	On the underside of the machine, unscrew and remove the four screws highlighted (Red circles) Put your hand under the machine and support the floppy drive as you turn the case back over.
	Now lift the rear edge of the floppy drive upwards, noting that it is secured to the case by a tab of plastic, more wriggling required. Finally, carefully pull the ribbon cable out of the connector. It is a push fit only.
	We now need to remove the small upright power board. First grip the shield that seperates the board from the Hard Drive. It will come out with a slight pull. Then carefully grip the power board and pull it from its connector.
	This image shows the shield and power board removed from the base unit. Take time to note the shields orientation and the connector on the power board.
	To remove the hard drive and its attatched chassis, unscrew and remove the single screw highlighted. Next and most difficult, remove the IDE cable from the hard drive. This is really difficult as there is no slack in the cable, so take your time, working out one side then another.
	The Hard Drive and its chassis can now be lifted clear of the base unit.
	remove the four screws highlighted to seperate the hard drive from its chassis.
	This image shows the old drive (top), original CONNER CP2064 64Mb and the replacement drive (below), which is a SEAGATE 80Mb unit. Be careful selecting a replacement drive as it must be less than 512Mb for optimal compatability and its physical size, in some cases could cause clearance problems.
	Re-assemble the machine using the reverse of the steps above. Check everything twice to ensure correct connections and securing screw locations. Power up the machine, and insert your Applications disc into the floppy drive. We now need to use !Hform to Format the new drive.
	The first thing it asks us is what drive to Format. In this case as its the only drive in the machine we enter "4" and press Return.
	!Hform now reads the drives physical information, reports what it has found and asks as to wether we would like to accept this disc shape. To which the answer is "y" ie accept the drive defaults.
	Next we are required to say wether we want to map out any disc faults, so I choose "a" ie no more changes to the defect list. It then asks us if we wish to Format or Initialise the drive. On a brand new drive Initialise it first then Format, but for this occasion where the drive was tested before shipping to me I will just Format.
	We now get asked if we want a soak test to find any defects, so I choose "short". and then finally we get the "Do you really want to do this" type message to proceed. So choose "y"
	Accept the default LFAU as 512 This is the Large File Allocation Unit value
	Finally formatting begins and at the end you are shown a summary of the results with the amount of free space available on the drive. Space will then take you back to the Pinboard.
	In this last image I have copied the contents of the RISC OS 3 Applications Floppy Disc to the newly formatted hard drive (green highlight). The machine is now ready to have a !Boot file made and any other software to be installed.

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