158 Netfinity 3500-M20 – Type 8657 Models 21Y, 22Y, 31Y, 32Y,
machine, as it was designed and built, had required safety
items installed to protect users and service personnel from
injury. This gu ide addresses only those items. However,
good judgment should be used to identify potential safety
hazards due to a ttachment of non-IBM f eatures or options
not cove red by this inspection guide.
If any unsafe conditions are present, you must determine
ho w se r io us the appa r e nt ha za r d co ul d be and wheth er yo u
can continue w ithout first correcting the pro blem.
Consider these conditions and the safety hazards they
present:
• El ec tr i ca l ha zards , es pe c ial ly pr im ar y powe r (pr i ma r y
voltage on the fram e can cause serious or fatal electri-
cal shock).
• Explosive ha zards, such as a damaged CRT face or
bulging capacitor
• Mecha nical hazar ds, such as loose or missing hard-
ware
The guide consists of a series of steps presented in a check-
list. Begin the checks with the power off, and the power cord
disconnected.
Checklist:
1. Check ext erior covers for damage (loose, broken, or
sharp edges).
2. Pow er-o ff the computer. Disconnect the pow er cord.
3. Check the power cord for:
a. A third-wire ground connector in good condition.
Use a meter t o meas ure third-wire groun d conti-
nuity for 0.1 ohm or less betwee n the ex ternal
ground pin and frame ground.
b. The power cord should be the appropriate type as
specified in the parts listings.
c. Insulation must not be frayed or worn.
4. Remo ve t he cover.
5. Check for any obvious non-IBM alterati ons. Us e good
judgment as to the safety of any non-IBM alterations.
6. Check inside the unit for any obvious unsafe condi-
tions, such as metal filings, contamination, water or
other liquids, or signs of fir e or smoke damage.
7. Check for worn, frayed, or pinched cables.
8. Check that the power-supply cover fasteners (screws
or rivets) ha ve not been removed or ta mpered with.

Handling electrostatic discharge-

sen sitiv e d evices

Any computer part containing transistors or integrated cir-
cuits (ICs) should be considered sensitive to electrostatic
discharge (ESD). ESD damage can occur when there is a
difference in charge between objects. Protect against ESD
damage by equalizing t he charge so that the machine, the
part, the work mat, and the person handling the part are all
at the same charge.