Acorn FileStore E01, Service Manual

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Chapter 5 E01 Fault finding
FileStore Service Manual 25
5. E01 Fault finding
The following chapter describes the suggested methods of fault finding on a FileStore E01
unit when the fault is not clearly in a specific area.
When the FileStore E01 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 disc drive activity light for any connected FileStore E20 will flicker
(3) The floppy disc drive indicator for the FileStore ECU will light up.
(4) All indicator lights should then extinguish, except the power indicator lights. The
FileStore E01 is now ready for use.
If the power on routine fails, then the File-Store is faulty.
Follow the fault finding procedures outlined below. These should help you to discover any
basic fault with the FileStore. The procedure consists of disco discrete stages, which should
be followed in the order they are described.
5.1 Stage 1: Initialisation
If you have a suitable printer available, plug it into the unit and turn it on. Open the unit‘s
Access flap and then turn the unit on, while observing the printer. If the printer performs a
line feed, proceed with stage 2
If the printer does not perform a line feed, check the following with an oscilloscope:
Processor clock: 2MHz on pin 3 and 39 of IC3
NMI line: High end pin 6 of IC3
RTC frequency: 1024 kHz at TPI (at IC2)
Address lines: for activity (at IC3)
Darn lines: for activity (at IC3)
5.2 Stage 2: Net link
If it appears that the link to the network is failing, the most common causes are:
Symptom
action
Net module faulty
Replace it
No clock Check clock path and enable
Line jammed Check for approximately 0.3V across the data pair
5.3 Stage 3: Final checks
If the procedure outlined above fails to uncover the fault, then as a final check, you should
refer to Appendix A -
Test Equipment at the back of this manual, which contains more
thorough tests of the FileStore.