The amp board is the long board on the
right handsideof theGCchassis interior
ELECTRONICS
Replacing the OP-Amp Chip in Your SRI GC
OP80AmpChip
Marker
1. TurnOFFandunplug theGC.
2. Remove the6screwsholding thebottompanelon theGC
chassis. SupportthepanelwhileyougentlyrocktheGContoits
back, then lower thepanel toyourworkingsurface toaccess the
chassisinterior.
3. Locate theAmpboard
inside theGC chassis on
the right hand side.
Remove the protective
steelplatebylooseningthe
two thumbscrews that
secure it to thealuminum
stand-offs,andset itaside.
4. Thereare fourpossibleplaceson theAmpboard for theOP-Amp
chip,dependingon thedetector towhich it isassigned. From the top(or
front,withtheGCinnormaloperatingposition), theAmpboardsections
readFPD,FID,PID, andDELCD. Ifpresent, theNPDwillbeat the
FIDposition,aswouldaTID ifpresent. However,because thecircuits
areidentical,thisisjustageneralguide. TheAmpboardwillbepopulated
according to thedetectors installedon theGC. Note that eachcircuit
hasapairofchips,almost identical inappearance, installedsidebyside;
theOP-Ampchip is theoneon the left.
5. Useasmallflatbladescrewdriverorsimilar tool topry theOP-
Amp chipout of its socket andoff theAmpboard. (Apocket
knifenailfilewasused in thepicture).
6. Notethesemi-circulardepressiononone
endof theOP-Ampchip; this is amarker
for proper orientation of the chip, and it
corresponds with a similar mark on the
socket. The end of the chip bearing the
marker faces the topof theampboard, so
youwill install itwith thatendfacingaway
fromyou. Carefullyposition thechipover
the socket so that each of the eight pins
occupiesaholeandpress it intoplace.
7. Test thenewOP-Ampchipwith themethodsdescribedon thepreviouspage.
Replacing theOP-AmpChip
Picturedhere is
an amp board
with two OP80
ampchipson it.
Detector
section
Detector
section
