HP Car 3490A manual Hffi3, 338r

CHECK OPERATION OF ISOLAIING PHOTO.TRANSISTORS UI THFOUGH UTI WITH A LOGIC PROBE OF BY CONNECTItrG A KNdN GOOD UNIT IN

PABALLEL WITH THE SUSPECTED PHOTO.TNANSISTOR IN THE 3$A.

A5O CHECK ORIVE TRANSISTOFS

A@ AHFOUGH @ ANO A35O1 THBOUGH 04 . Se Note l .

Hffi3

6E CAAE II HAXOLING ISOLATION

SEüBIIES. PHOTO.TAAilSISTOAS U1

üBOUGH Ul' ARE VEFY SENTIVE

TOTEqAXICAL STßES.

BEMOVE 44 ANO NEPLACE Ag ANO A36 . MEASURE + 12 V . + 5 V . sd . 2 V OUTGUARO VOLTAGES . +12V AND

. 2V TEST POINTS AAE ON A32 AND +5V TEST POINT IS ON A33 . VOLT .

AGES MUST AE MEASURED TO OUT . GUABO GAOUND T € ST POINT ON A33 OF A3O . ALLOW +/ . 16 TOLLEAANCE,

ANE ISOLATION CIRCUIE OPERA- TING CORFECTLY?

IROUELESHOOT OUTGUARD VOLT.

AGE SUPPLIES . +lzv . nd +5V sUP -

PLI€S ABE LOCATEO ON OUTGUAFD MOTHEF EOAAO A3I . ,2 V SUPPLY IS OEVELOPEO FROM SYST€M CIOCK MULTTVIAAATOF ON A32.

THIS CHECK SUMES THAI ONLY ONE GPIBPRINTEO CIRCUIT AS € U -

a L Y 1 5 O E F E q I V E . 6 r N G A $ € M .

BLIES IN GPIB REPAIR KIT NO .

OSS.A(rc, SUSSTITUIE A$EMALIES ON € AT A TIME IN THE FOLLOWING OROEF: A32, A3, A36 . A34 . AND ISO -

LATION SEMBLIES AS ANO A35 TOGETHEA . AFTER SUBSTITUTING EACH ASSEMBLY, PERFORM THE OPERATING CHECK GIVEN IN PARA .

GAAPH 5 . 7 OR '9 TO OETERMTNEIF PROBLEM IS CLEAAED . Se Note 2,

PROELEM MAY AE ON OUTGUAAD MOTHER BOAFO A3i OR IN A $ It AUS .

SUBSTITUTE NEW 'AFE {KIT NO .

ogw@31) FoB a3ru2 aND 3 . THS CHECKS OATA ANO CdTNOL LINE BUFFERS ANO GATES. Se Note 2.

rcES ASCII OPERATE COFRECTLY?

USE APPROPAIATE R NOTEO IN THE FOLLO REPAIR OEFECTiVE S

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3490 - D - 338r