Appendix, cont’d
USP 405 • Appendix
A-6
U60 or U24
Locating the four firmware IC chips
5.
After you are electrically grounded, the U67 and U68 IC chips (which must
be replaced as a pair) may be removed by grasping each chip firmly with
your fingers and pulling it out, then continuing to step 8.
Removal of the U60 and U24 IC chips requires a
PLCC IC puller tool. To remove either chip,
align the hooks of a PLCC IC puller tool with
the slots located in opposite ends of the
firmware chip.
6.
Insert the hooks into the slots, and squeeze the
tool gently to grasp the chip.
7.
Pull the chip straight out of the socket, and set it
aside.
8.
For U67 and U68
, align the slots of the new
firmware chip with the notches of the socket in
the same orientation as the old chip. Gently,
but firmly, press the chip into place in the
socket.
9
.
For U60 and U24
, note the key (angled
corner) of the new firmware IC and the
dot on the underside that indicates
pin 1. Orient the IC to match the key
and pin 1 (indicated by arrow) on the
socket, and gently, but firmly, press the
IC into place.
Key
Pin 1 mark
Pin 1 mark
Socket
IC
Key
U24
U60
U67
U68
Align Notche
s
U67 or U68
im Vertrieb von
CAMBOARD Electronics
www.camboard.de
Tel. 07131 911201
Fax 07131 911203