Replacing Boot Eproms - Allied Telesis AR Series Hardware Reference Manual

108

Replacing Boot EPROMs

AR300 Series routers have one boot EPROM and AR720/AR740 routers have
two boot EPROMs. Boot EPROMs contain bootstrap code, which loads the
main code from a software release file in flash memory. In rare circumstances
the boot EPROM(s) may need to be changed. AR725 and AR745 routers do not
have boot EPROMs.
Boot EPROMs do not need to be replaced, except in rare circumstances. Boot
EPROMs should only be replaced by authorised service personnel. Contact
your authorised Allied Telesyn distributor or reseller. Unauthorised opening of
the router lid may expose you to live components and a risk of injury from
electric shock, it may also damage the router and invalidate the product
warranty.
To change the boot EPROMs:
1. Check that you have the correct tools and equipment available.
You will need a medium sized posidrive screwdriver and an EPROM
extraction tool (or a small flat bladed screwdriver). In addition, adequate
antistatic precautions must be observed.
EPROMs, like most electronic equipment, are highly sensitive to electrostatic
damage. This can be particularly acute in the dry atmosphere normally
associated with computer rooms and typical offices. Before commencing work,
ensure that you have used an approved antistatic wrist strap to discharge any
buildup of static electricity. Wear the strap at all times during the following
procedure.
2. Avoid injury by working in a safe environment.
The workspace should be free of hazards, and there should be sufficient
room to lay out the router, the expansion card and the tools.
3. Turn OFF the router and remove the mains power cord.
Do not take risks with mains electricity. Do not attempt to remove the lid of a
router unless the power cord has been removed from the router.
4. Remove the router lid.
The router lid is secured by posidrive screws. Remove the screws and lift
the lid off the chassis.
The router may need to be removed from any racking system before the lid
can be removed.
5. Remove any MAC card (AR300 Series only).
On AR300 Series routers, if a MAC card is installed then it must be
removed to gain access to the boot EPROM. See "Installing a MAC" on
page A-69 for instructions.
6. Remove the existing boot EPROMs.
The boot EPROM(s) should now be visible on the CPU board. Table 41 on
page 109 lists diagrams showing the location of boot EPROMs on each
AR Router
C613-03031-01 REV E