Circuit-Board Pins; Front-Panel Lights; Adjustment After Repair; Instrument Repackaging - Tektronix 7B85 Instruction Manual

damaged end-lead pin connectors, remove the old pin con-
nector from the end of the lead and clamp the replacement
connector to the lead.
Some of the pin connectors are grouped together and
mounted in a plastic holder; the overall result is that these
connectors are removed and installed as a multi-pin connec-
tor (see Fig. 4-4). To provide correct orientation of this multi-
pin connector when it is replaced, an arrow is marked on the
circuit board and a matching arrow is molded into the plastic
holder of the multi-pin connector. Be sure these arrows are
aligned as the multi-pin connector is replaced. If the individ-
ual end-lead pin connectors are removed from the plastic
holder, note the color of the individual wires for replacement.
Inter-Board Multi-Pin Connector. The inter-board multi-
pin connector pin-holder is not repairable and should be re-
placed as a unit (see Fig. 4-3). Refer to the Replaceable
Mechanical Parts list for part number. Inter-board multi-pin
connector pin-sockets are soldered to circuit boards (see
Fig. 4-3). To replace a socket, first remove the guide. Then,
remove the old socket using soldering techniques previously
described. Solder the new socket in place, making sure it
will align properly with the inter-board connector pins.
Circuit-Board Pins
All circuit boards in this instrument, except the
Readout circuit board, are multi-layer type boards
with a conductive path(s) laminated between the top
and bottom board layers. All soldering on these
boards should be done with extreme care to prevent
breaking the connection to the center conductor(s);
only experienced maintenance personnel should at-
tempt repair of these boards.
A circuit-board pin replacement kit including the neces-
sary tools, instructions, and replacement pins is available
from Tektronix, Inc. Order Tektronix Part No. 040-0542-00.
Replacement of circuit-board pins on multi-layer boards is
not recommended; refer such repairs to your local Tektronix
Field Office or representative.
To replace a damaged pin mounted on a single-layer cir-
cuit board, first disconnect any pin connectors. Then (using
Soldering Techniques given earlier in this section), unsolder
the damaged pin and pull it from the board with a pair of
pliers, leaving the ferrule (see Fig. 4-11) in the hole, if possi-
ble. If the ferrule remains in the circuit board, remove the
spare ferrule from the replacement pin and press the new
pin into the hole in the circuit board. If the ferrule is removed
REV AUG 1981
Maintenance-7B85
with the damaged pin, clean out the hole using a solder-
removing wick and a scribe. Then, press the replacement
pin with attached spare ferrule into the hole. Position the
replacement pin in the same manner as the damaged pin.
Solder the pin to the circuit board on each side of the board.
If the old pin was bent at an angle to mate with a connector,
carefully bend the new pin to the same angle. Replace the
pin connector.
Front-Panel Lights
This instrument uses LED's (light-emitting diodes) and
incandescent lamps for front-panel lights.
LED's are used to illuminate the TRIG'D and SINGLE
SWP READY lights. To replace LED's, remove the cap from
the sleeve as in Fig. 4-12. Note the lead wire color coding
and the LED lead configuration. Unsolder the wire leads and
remove the LED from the cap. Solder the replacement LED
and lead wires to the socket cap as noted previously. Install
the cap in the sleeve.
Incandescent lamps are used to illuminate the transpar-
ent pushbutton switches. To replace incandescent lamps,
unsolder the lead wires from the rear of the cap (see Fig.
4-12) and pull the cap and bulb out of the sleeve. Solder the
replacement lamp and lead wires to the cap. Install the as-
sembly in the sub-panel sleeve.
ADJUSTMENT AFTER REPAIR
After any electrical component has been replaced, the
adjustment of that particular circuit should be checked, as
well as other closely related circuits. See Section 5 for a
complete adjustment procedure.
INSTRUMENT REPACKAGING
If the Tektronix instrument is to be shipped to a
Tektronix Service Center for service or repair, attach a tag
showing: owner (with address) and the name of an individ-
ual at your firm that can be contacted, complete instrument
serial number, and a description of the service required.
Save and re-use the package in which your instrument
was shipped. If the original packaging is unfit for use or not
available, repackage the instrument as follows.
1. Obtain a carton of corrugated cardboard having inside
dimensions of no less than six inches more than the instru-
ment dimensions; this will allow for cushioning. Refer to
Table 4-1 for carton test strength requirements.
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