Shunt Block Modification - HP 7942 Service Manual

Service Notes
7942 and 7946
7941-04
7945A-04
SERVICE
NOT E
Supenedes:
SUPERSEDES:
7941/45A DISC DRIVE
SHUNT BLOCK MODIFICATION
PARTS AFFECTED:
D:[SC MECHANISM
079J~1-60021 new
07941-69021 exchange
and
DISC MECHANISM
079 J I5-60021 new
07945-69021 exchange
DRIVE SERIAL PREFIX:
2440 or less
APPLIIS TO:
AI Unttl a
Only
Unit'
on
Agreemenatl
PERFORM:
Immediately a
At
PMINormai
calfJCJ
On Flilure a Information Only a
WARRANTY: IXTENDED NORMAL NONE
LABOR:
0.5
PARTS:
no
TRAVEL: no
SERVICE Return for upcMt. a Ute_ita
INVENTORY
Return for
u.".
a
SIt
t.xt~
WARRANTY EXTENDED UNTIL:
February
1986
SYMPTOM: Possible drive not ready, after replacing a DDC PCA
(part nos. 07941-69002 or 07941-69102).
CAUSE: The shunt· block J6 on the Disc Mechanism (part nos.
07941-60021, 07941-69021, 07945-60021, or 07945-69021).
SOLUTION: Perform the following upgrade to the Disc Mechanism on AN
failure of a drive with a serial prefix of 2440 or less:
HW/rl
1.) Remove the Disc Mechanism, part number 07941-6X021 or
07945-6X021 per procedure 5-11 in 7941/45A Service
Manual.
2.) Remove the mounting tray attached to the bottom of the
Disc Mechanism and lay the Disc Mechanism on its top to
expose the component side of the Data PCA.
3.) Locate the Shunt Block J6. It is a socket ted jumper
block located between edge connectors J1 and J2 on the
Disc Mechanism.
4.) Cut the following three shunts on the Shunt Block with an
exacto knife: 7-10, 6-11, and 5-12. Only shunts 3-14,
4-13 and 8-9 should be intact on a 7941A and shunts 4-13
and 8-9 should be intact on a 7945A Disc Mechanism.
Refer to the following diagram of a modified Shunt Block:
9320-4766
(1/8:~)
rl~
HEWLETT
a:!tI
PACKARD
FOR MORE INFORMATION,
CALL
YOUR
LOCAL . . IALEI OR
IERYICE OFFICE or EDt
12011
-..000.
Midwest 13121 255-Il00 • Sou .... 14041
"'&00 •
Welt
12131 170-7&00 or 14151 HI-12OO"
OR WRITE,
Hewlltt-hcUrd, 1120 Ema.c.dero, Palo Alto, C.llforn.lM303.
IN EUROPE,
CALL
YOUR
LOCAL HP IALEI or
.RVICI OFFICI Ott WR.TI,
Hewlett.pec:kerd I.A., 7, rue du
loil-du-un, P.O. 80.,
CH-1217
Mtyrin
2 -
Geneve,
Switzer"'.
IN
J//I#AN, Yoko..,.-HlWIItt-hcklrd Ltd.,
1-27-11, Yebe ...... 1Nre City, K ....... Prefecture,
Jepen
221.
@
1983
H.w"tt.-I~eckerd
Compeny
Printed In U.S.A.
8-11