WFM90D and WFM91D ServiceManual 8-1
Replaceable Parts List
This section lists the replaceablem odulesfor this instrument. Use this list to
identify and orderreplacement parts .

Parts OrderingInformation

Replacement parts are available through your local Tektronix, Inc., Field Office
or representative.
Changes to Tektronixinstruments are sometimes made to accommodate
improved componentsas they become available and to give you the benefit of
the latest circuitimprovements. Therefore, when ordering parts, it is important to
include the following informationin your order:
HPart number
HInstrument type or model number
HInstrument serialnumber
HInstrument modificationnumber, if applicable
If you order a part that has been replaced with a different or improved part, your
local Tektronix,Inc., Field Office or representative will contact you concerning
any changein part number.
Modules can be servicedby selecting one of the following three options. Contact
your local Tektronixservice center or representative for repair assistance.
ModuleExchange. In some cases you may exchange your module for a reman-
ufacturedmodule. These modules cost significantly less than new modules and
meet the same factoryspecifications. For more information about the module
exchangeprogram, call 1-800-833-9200. Outside North America, contact a
Tektronixsales office or distributor; see the Tektronix web site for a list of
offices:www.tektronix.com.
ModuleRepair and Return.You may ship your module to us for repair, after which
we will returnit to you.
NewModules. You may purchase replacement modules in the same way as other
replacement parts.

Module Servicing