Ferrite Bead Rework Instruction
Reference: Use this instruction to install part
91035.
Tools Needed: Phillips screwdriver, flat-blad-
ed screwdriver, static ground-
ing (earthing) wrist strap
(included).
Warning-Hazardous Voltage
Warning-Internal components may be
damaged by static electricity.
CAUTIONS:
• Power cord must be disconnected to
prevent electric shock.
• Never unpack, touch or handle any
integrated circuit without wearing a
grounding (earthing) strap to mini-
mize your static charge.
Advanced Instruments, Inc. has identified a
condition affecting some instruments,
described in your service manual as Stir
Driver Noise. This electrical noise can be the
cause of false pre-freeze errors, sample freeze
errors, and in some cases may also contribute
to poor repeatability and excessive wear of the
stir coil and clapper assembly.
It is recommended that this update be added to
your 4D3 and 3D3 instruments. All products
manufactured starting in September 2003 have
this modification as standard equipment,
installed as described in “Factory-installed
Upgrade (Option B)”.
Determining Need of Upgrade:
1. Turn off the instrument power and discon-
nect the power cord.
2. Remove the two screws holding the cover
on the sample head assembly.
3. Locate the white wire exiting the head
shaft and running to the head transition PC
board.
4. If you see the white wire passing through
a round black bead(s) as shown in the
installation option A or B pictures, then
your instrument already contains this
update and you may disregard this docu-
ment.
5. If you do not have one of these beads
installed, then please follow the installa-
tion instructions, below.
Upgrade Installation (Option A):
1. Locate the two ferrite beads, Part No.
91035, shipped with this kit.
2. Locate the white wire and its connection
to terminal TR2 on the head transition
board.
3. De-solder the wire and slip it through the
center of the two ferrite beads.
4. Re-solder the wire to the TR2 terminal.
5. Check terminal TR2 to verify that it has
not become loose from the printed circuit
board. If necessary, apply some heat and
solder to the back of TR2 to secure it in
place.
6. Use the stir/freeze test and stir/freeze
alignment instructions contained in your
user’s guide to verify correct operation.
7. Restore the head cover and screws.
Factory-installed Upgrade (Option B):
This option is the standard factory installation.
These photographs have been provided as ref-
erence only, for determination of the installed
upgrade. Field upgrades should use option A,
as described above.
4SP475 Rev0
(4D35 Service Manual)
Page 1 of 2
For additional information or technical assistance,
please contact Advanced Instruments Hot-Line
®
Service Center (U.S. 1-800-225-4034, outside
North America +US 1-781-320-9000).
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