Acorn FileStore E01, Руководство по обслуживанию

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Chapter 5 E20 Fault finding
FileStore Service Manual 47
5. E20 Fault finding
The following chapter describes the suggested methods of fault finding on a FileStore E20 unit
when the fault is not clearly in a specific area.
When the FileStore E20 is powered up, the following sequence of operations, should take place, as
indicated by various activity indicators on the FileStore:
(1)
On initial power up, the power indicator and mode/activity indicator should light up.
(2)
The hard disc will spin up to speed in about 10 seconds. This process produces a rising pitch
humming noise which means that the hard disc is spinning. If the disc is not spinning, then
check the power supply and connections.
(3)
The floppy disc drive indicator for the FileStore E01 will light up.
(4)
All indicator lights should then extinguish, except the power indicator lights, on the FileStore
E01 and the connected E20. The FileStore E20 is now ready for use.
If the above power on routine fails, then the FileStore is faulty. Follow the fault finding procedures
outlined below. These should help you to discover any basic fault with the FileStore.
The E20 unit consists of three major components:

the hard disc drive

the Host Adaptor board

the switch-mode power supply
5.1 Power supply
The E20 unit is powered by a switch mode power supply. The power supply output cables are
colour-coded as follows:
black
ground
red
+5V
orange
+12V
The power supply can be tested by measuring the +5 voltage between the black and red cables, and
the +12 voltage between the black and orange cables. The allowable voltage ranges are as follows:
+5V (black and red)
4.9 V to 5.2V
+12V (black and orange) 11.4V to 12.6V
These measurements should be made with all connectors in place.
Next measure the current drawn by each of components specified above from the +5V and +12V
supplies. The current measurement should be series with either the red cable (+5V) or the orange
cable (+12V). The connections to the meter to do this must be made with the power switched off.
The measurements must be made after power-up as some of the circuitry, when working correctly,
will alter its current consumption with time as show below. The current drawn by each component
from each voltage rail should be as follows: