Tait T850 II Series, Service Manual

Page: 313 / 370

M850-00
Introduction E1.1
Copyright TEL 31/09/98
1 Introduction
PCB Identification
All PCBs are identified by a unique 10 digit “internal part number” (IPN), e.g. 220-12345-00, which
is screen printed onto the PCB (usually on the top side), as shown in the example below:
The last 2 digits of this number define the issue status, which starts at 00 and increments through 01,
02, 03, etc. as the PCB is updated. Some issue PCBs never reach full production status and are there-
fore not included in this manual. A letter following the 10 digit IPN has no relevance in identifying
the PCB for service purposes.
Note: It is important that you identify which issue PCB you are working on so that you can
refer to the appropriate set of PCB information.
Parts Lists
The 10 digit numbers (000-00000-00) in this Parts List are “internal part numbers” (IPNs). We can
process your spare parts orders more efficiently and accurately if you quote the IPN and provide a
brief description of the part.
The components listed in this parts list are divided into two main types: those with a circuit refer-
ence (e.g. C2, D1, R121, etc.) and those without (miscellaneous and mechanical).
Those with a circuit reference are grouped in alphabetical order and then in numerical order within
each group. Each component entry comprises three or four columns, as shown below:
The mechanical and miscellaneous section lists the variant and common parts in IPN order.
circuit reference -
lists components
in alphanumeric
order
variant column -
indicates that this is
a variant component
which is fitted only to
the product type listed
Internal Part Number -
order the component
by this number
description -
gives a brief description
of the component