Tektronix 454A - Troubleshooting

M
ai nt enance- 454zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA ‘ / R 454A
C R T . Cl ean t h
e pl ast i c l i g h t f i l t er an d t h e C R T f ace onl y

F an . T h e f an- mot or bear i n gs ar e seal e d an
d d o n ot r e
wi t h ± sof t ,
l i nt - f r ee cl ot h d am p ened wi t h ± mi l d d et er gent

qu i r e l u br i cat i on .
an d wat er sol ut i on . T h e C R T mes h f i l t er can be
cl eane d i n
t he f ol l owi ng manner .
1 . H ol d t h e f i l t er i n ± ver t i cal p
osi t i on an d br us h l i g h t l y
wi t h ± sof t #7 wat er - col or
b r us h t o r emove l i g h t coat i ngs of
du st or l i nt .
2 . Gr easy r esi d ues or dr i ed- on d i r t can b e r emoved wi t h
± sol ut i on of war m wat er an d ± ne u t r al - ¡ — l i q ui
d d et er gent .
U se t h e b r u s h t o l i g h t l y
scr ub t h e f i l t er .
3 .
R
i nse
t he f i l t er t h or oug h l y i n cl ean wat er and al l ow i t
t o
ai r
d
r y
.
4 . I f t h e l i nt or d i r t r emai ns, use
cl ean
l ow- pr essur e
ai r t o
r emove . Do not use
t weezer s or ot her h ar d cl eani ng t ool s
on t h e f i l t er ,
as
t h
e speci al f i ni s h may b e damage d .
5 . Wh en not i n u se, st or e t h e mes
h f i l t er i n ± l i nt - f r ee,
d ust - pr oof cont ai ner suc
h as ± pl ast i c bag .
I nt er i or . Dust i n t h e i nt er i or of t h e i nst r u ment s h oul d b e
r emove d occasi onal l y d u e t o i t s el ect r i cal con
d
uct i vi t y
un
d
er
h
i g h - h umi
d
i t y
con d i t i ons . T h e b est
way
t o cl ean t h e
i nt er i or i s
t o
b l ow of f t h e acc u mul at ed d ust wi t h d r y, l ow-
vel oci t y ai r . R emove any di r t w h i c h r emai ns wi t h ± sof t
p ai n t br us h or ± cl ot h d am p ene d wi t h ± mi l d d et er gent and
wat er sol ut i on . ‘ cot t on- t i ppe
d appl i cat or i s u sef u l f or
cl eani ng i n nar r ow s p aces or f or cl eani ng cer ami c t er mi nal
st r i p s and ci r cui t boar d s .
T h e h i g h - vol t age ci r cui t s, p ar t i c u l ar l y p ar t s l ocat e d i n
t h e h i g h - vol t age com p ar t ment an d t h e ar ea s u r r o u n d i ng t h e
p ost - d ef l ect i on ano d e connect or , s h o u l d r ecei ve s p eci al
at t ent i o n . E xcessi ve d i r t i n t h ese ar eas may cause h i g h -
vol t age ar ci ng a n d r es u l t i n i mp r o per i nst r ument o p er at i on .
4- 2
V i sual I ns p ect i on
T h e 454 ‘ s h oul d be i ns p ect e d occasi onal l y
f or
suc
h
d ef ect s as br o k en connect i ons, b r o
k
en or damage
d cer ami c
st r i p s, i mp r o p er l y seat e d t r ansi st or s,
d
amage
d ci r c u i t boar ds
an d h eat d amaged
par t s .
T h e cor r ect i ve p
r ocedur es f or most vi si b l e d ef ect s i s
obvi ous ;
h owever , p ar t i c u l ar car e m u st b e t a k en i f
h
eat - damage d com p onent s ar e f o u n d . Over h eat i ng usual l y
i ndi cat es
ot h er t r o u bl e i n t h e i nst r ume n t ; t h er ef or e, i t
i s
i m p or t ant t h at t h e ca u se of over h eat i ng be cor r ect e
d t o
p r event r ecur r ence of t h e d amage .
Tr ansi st or C
h
ec
k s
P er i o d i c c h ec k s of t h e t r ansi st or s i n t h e
454
‘ ar e
not
r ecommen d e d . T h e b est c h ec
k
of
t r ansi st or p er f or mance i s
i t s act u al oper at i on i n
t h e i nst r ume n t . M or e d et ai l s on
c h ec k i ng
t r ansi st or oper at i on ar e gi ven under Tr o ub l e-
s h oot i ng .
R ecal i br at i on
To assur e
acc
u
r at e meas u r ement s, c h ec k t he cal i br at i on
of t h i s i nst r ument
af t er eac h 1000 h our s of o p er at i on or
ever y si x
mont h s i f use d i nf r e q uent l y . I n a dd i t i on, r e p l ace-
ment of com p onent s may necessi t at e r ecal i br at i on of t
h
e
af f ect e d ci r cui t s . Com p l et e cal i
b r at i o
n
i nst r uct i ons ar e
gi ven i n t h e Cal i b r at i on
sect i on
.
T h e cal i br at i on p r ocedur e can al so b e h el p f ul i n l ocal -
i zi ng cer t ai n t r o u bl es i n t
h
e
i nst r u
ment
. I n some cases,
mi nor
t r o u bl es
may b e r eveal e d an d / or cor r ect e d b y r ecal i -
b
r at i on .
I nt r o d uct i on
T R
O
UBLE S H OOTI N G
L ubr i cat i on
T h e f ol l owi ng i nf or mat i on i s p r ovi ded t o f aci l i t at e
Gener al . T
h
e
r el i a b i l i t y of p ot ent i omet er s, r ot ar y

t r o ub l es h oot i ng of t h e 454 ‘ . I nf or mat i on cont ai ne d i n
swi t c h es an d ot h er movi ng p ar t s can b e mai nt ai ne d i f t h ey

ot h er sect i ons
of t h i s manu al s h o u l d b e u se d al ong wi t h t h e
ar e k e p t p r op er l y l u br i cat e d . U se ± cl eani ng- t y p e l ub r i cant

f ol l owi ng i nf or mat i on t o ai d i n l ocat i ng t h e d ef ect i ve
( e . g . , Te k t r oni x P ar t No . 006- 0218- 00) on swi t c h cont act s .

component . An u n d er st an d i ng of t h e ci r cui t o p er at i on i s
Lub r i cat e swi t c h det ent s wi t h ± h eavi er gr ease ( e . g . , Te k -

ver y h el p f ul i n l ocat i ng t r o ub l es . See t he Ci r c u i t Descr i p -
t r oni x P ar t No . 006- 0219- 00) .
P
ot ent i omet er s
w h i c h ar e

t e r n sect i on f or com p l et e i nf or mat i on .
not p er manent l y seal e d s h oul d b e l u b r i cat e d wi t h ± l u br i -
cant w h i c h d oes not af f ect el ect r i cal c h ar act er i st i cs ( e . g . ,
Te k t r oni x P ar t No . 006- 0220- 00) . T h i s l u br i cant can al so

Tr oubl es h oot i ng Ai d s
be use
d
on s h af t bus
h
i ngs . Do not
over l
ub
r i cat e
.
‘ l u br i -
cat i on k i t cont ai ni ng t h e necessar y l u b r i cant s an d i nst r u c-

Di agr ams . Ci r cui t d i agr ams ar e gi ven on f ol d o u t pages i n
t i ons i s avai l a b l e f r om Te k t r oni x, I nc . Or d er Te k t r oni x P ar t

Sect i on 8 . T h e com p onent number an d el ect r i cal val ue of
No . 003- 0342- 00 .

eac h comp onent i n t h i s i nst r ument ar e s hown on t h e