IBM 390E manual For Worn Frayed Pinched Cables

The guide consists of a series of steps presented in a checklist. Begin the checks with the power off, and the power cord disconnected.

Checklist:

1.Check exterior covers for damage (loose, broken, or sharp edges).

2.Power-off the computer. Disconnect the power cord.

3.Check the power cord for:

a. A third-wire ground connector in good condition. Use a meter to measure third-wire ground conti-

nuity	for	0.1	ohm or less between the external
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.Remove the cover.

5.Check for any obvious non-IBM alterations. Use

good judgment as to the safety of any non-IBM alter- ations.

6.Check inside the unit for any obvious unsafe condi-

	tions,	such	as	metal	filings,		contamination, water			or
	other	liquids,		or signs of fire or smoke damage.
7.	Check	for	worn,	frayed,		or	pinched		cables.
8.	Check	that	the	power-supply			cover	fasteners (screws
	or rivets)		have	not	been	removed		or	tampered	with.

14 ThinkPad 390E