Lenovo ThinkCentre A35, Service Manual

Page: 60 / 67

59
Ele c tri c al safety
C AU TION:
Electrical current f ro m po w er, telephone, and co mm unication cables can be hazardous. To a v oid
personal injur y or equip m ent da m age, disconnect the attached po w er cords, teleco mm unication
s y ste m s, net w or k s, and m ode m s be f ore y ou open the ser v er/ w or k station co v ers, unless instructed
other w ise in the installation and con f iguration procedures.
Obser v e the fo ll o w ing ru l es w hen w orking on e l ectrica l equipment.
I m portant:
Use on ly appro v ed too l s and test equipment. S ome hand too l s ha v e hand l es co v ered w ith a
soft materia l that does not insu l ate y ou w hen w orking w ith l i v e e l ectrica l currents. Man y
customers ha v e, near their equipment, rubber f l oor mats that contain sma ll conducti v e fibers to
decrease e l ectrostatic discharges. Do not use this t y pe of mat to protect y ourse l f from e l ectrica l
shock.
w!
Find the room emergenc y po w er-off (EPO) s w itch, disconnecting s w itch, or
e l ectrica l out l et. If an e l ectrica l accident occurs, y ou can then operate the
s w itch or unp l ug the po w er cord quick ly .
w!
Do not w ork a l one under hazardous conditions or near equipment that has hazardous v o l tages.
w!
Disconnect a ll po w er before:
– Performing a mechanica l inspection
– W orking near po w er supp l ies
– Remo v ing or insta ll ing main units
w!
Before y ou start to w ork on the machine, unp l ug the po w er cord. If y ou cannot unp l ug it, ask the
customer to po w er-off the w a ll box that supp l ies po w er to the machine and to l ock the w a ll box in the off
position.
w!
If y ou need to w ork on a machine that has exposed e l ectrica l circuits, obser v e the fo ll o w ing precautions:
– Ensure that another person, fami l iar w ith the po w er-off contro l s, is near y ou.
Re m e m ber:
Another
person must be there to s w itch off the po w er, if necessar y .
– Use on ly one hand w hen w orking w ith po w ered-on e l ectrica l equipment; keep the other hand in
y our pocket or behind y our back
Re m e m ber:
There must be a comp l ete circuit to cause e l ectrica l shock.B y obser v ing the abo v e ru l e,
y ou ma y pre v ent a current from passing through y our bod y .
– W hen using testers, set the contro l s correct ly and use the appro v ed probe l eads and accessories for
that tester.
– S tand on suitab l e rubber mats (obtained l oca lly , if necessar y ) to insu l ate y ou from grounds such as
meta l f l oor strips and machine frames.
Obser v e the specia l safet y precautions w hen y ou w ork w ith v er y high v o l tages; these instructions are in
the safet y sections of maintenance information. Use extreme care w hen measuring high v o l tages.
w!
Regu l ar ly inspect and maintain y our e l ectrica l hand too l s for safe operationa l condition.
w!
Do not use w orn or broken too l s and testers.
w! Never assume
that po w er has been disconnected from a circuit. First,
check
that it has been po w ered-off.