Good source of information. What I need to know is how to get the cursor back. The cursor is on when it goes to the desktop and then it disappears. This is a new computer and I must have hit another button when typing.
Some very good suggestions, gentlemen. I wanted to keep it relatively simple, but some of those would definitely be good to add. I will see about adding details about fans, hinges, and batteries soon.
alternative method for checking bad pixels: show black-white checkerboard (1px) pattern, the interference should be visible
try warping lid: it may reveal torsion-dependent defects (bleeding)
image persistence (burn-in or ghost) : open checkerboard (make square size about 1cm) black-white pattern for a while (2-5minutes) then display gray background. The gray value is subject to tune (I recommend 40/256–80/256)
check for dust-like particles in the display.
check also strage spots (2mm) on max brightness : various solid backgrounds, black
check also PWM on various brightness levels: for CMOS camera use shortest exposure time possible: PWM present if single picture has black bands. For CCD, PWM present if series of images has different brightness. — Alternative method: in dark room, move pen/finger in front of LCD
check temporal noise: present in corners, more image patterns must be tried
check viewing angles: MSI advertises (and others may do too) IPS-Level for TN
check response times: for some usage scenarios (movies watching, animations), some LCDs have too long response times
More on chassis:
I had laptop with bad speaker connector contact. When I pressed palmrest or touchpad, sound muted
Nasty creaking noise when pressed chassis in various places
Fan(s) should be spinning fine. Rattling or grinding sounds indicate bearing problem.
The hinges should not wobble.
More:
Check if battery wear (or fully charged capacity) is correct: for new laptop zero percent wear, for used laptop if the value matches sellers's claim
Keyboards differ in number of simultaneously pressed keys that are correctly recognized. It is important for gaming and musician (musical notes /chords created by keyboard) applications. But the non conflicting key groups can differ (2x2 blocks or lines, columns, random)
For PWM ultra sensitive people: Even keyboard can have (and almost often have) PWM.
Touchpad problems
touchpad experience very depends on drivers/sofware. The scrolling performance may be different in browser and in other apps. If it does not work out of box, it require lot tweaking
Power adapter may also be source of hi-freq noise (buzz), even if not connected to laptop
Laptop may have also poor bluetooth and wifi reception signal. Some have bluetooth separately with poor antennae nearby SSD.