ComputingYou will see this often

LCD monitor

Also called flat panel, computer monitor.

The panel is the valuable part, and only if you photograph the model number on the metal back before the boards are separated from it. Everything else is a small supply, a backlight driver, and buttons.

A donor is the dead machine. The parts below are what is still worth removing from it. “Leave it” is a part that is physically in there and should stay in there: too dangerous, too worn, or only useful as part of a repair you are not doing.

What you are looking at

A scrapped machine is a box of parts that failed at different times. The reason it was thrown out is often one bad piece. The motor, the cord, the supply, and the screws are frequently still good. This index says which is which.

Why it is in the trash while the parts are not

A darker backlight, a cracked stand, or a bad capacitor in the supply. A cracked panel is glass and diffuser sheets, not a display.

Before you open it

Do this while it is still unplugged, cool, and not leaking. Unplug. Older units have a CCFL inverter at about a kilovolt. LED units are tamer but the backlight boost is still tens of volts.

Where the dead machine usually is

Home office — In the house
Office cleanout — Commercial
Bulk trash day — Curb

Write the panel code down at the curb if you are not taking the whole thing.

How it comes apart

Bezel clips. The panel label is on the back of the glass, under the boards. Photograph it, including the voltage sticker.

Tools: Phillips, Spudger, Camera.

Words on this page

capacitor: A part that stores a small amount of electrical energy. Large ones in power supplies can stay charged after you unplug. Discharge them before you touch the leads.
CCFL: The thin fluorescent lamp behind older flat screens. Its driver makes a high voltage. Do not run that board loose on the bench.

What to take

The table is the short version. The notes under it describe that part inside this machine, not only the general description.

Parts in this donor
Part	Call	How many	How often	Where to look
LCD panel	Prize	1	always	The glass.
Switch-mode wall supply	Worth pulling	1	usually	Internal board or a brick.
LED constant-current driver	Worth pulling	1	usually	With the supply or beside it.
LED array or COB	Bonus	2–4 strips	usually	Edges of the panel.
Speaker driver	Bonus	2	sometimes	Bottom corners, on models that had them.
Tactile switch	Bonus	4–7	always	The button board.
Enclosure	Bonus	1	always	Rear cover and stand.

Prize

Prize — take this firstLCD panel1 · always
LVDS or eDP, model-specific. The number is the whole salvage.
The glass.
Leave the panel in the frame until you have a controller in mind.
Cracks end it.

Worth pulling

Worth pullingSwitch-mode wall supply1 · usually
12 V or 19 V class, plus a backlight enable.
Internal board or a brick.
Label the outputs. Isolation-check an internal supply.
Caps fail here; look for bulges.
Worth pullingLED constant-current driver1 · usually
Constant current for that panel's strips.
With the supply or beside it.
Keep it with the panel.
Often the actual fault.

Bonus

Bonus, if you are already in thereLED array or COB2–4 strips · usually
Series LEDs. One open LED darkens a whole string.
Edges of the panel.
Do not peel them casually; they crack.
Mixed.
Bonus, if you are already in thereSpeaker driver2 · sometimes
Small, 4–8 Ω.
Bottom corners, on models that had them.
Unplug.
Fine.
Bonus, if you are already in thereTactile switch4–7 · always
OSD keys, already on a cable.
The button board.
Keep the board.
Good.
Bonus, if you are already in thereEnclosure1 · always
VESA mount is the useful hardware.
Rear cover and stand.
The plastic is brittle.
Mixed.