LightingYou will see this often
LED lamp
Also called LED bulb, GU10, A19.
A few LEDs and a driver. Many cheap bulbs are not isolated: the LED board sits at mains potential. Treat every one as live until you have looked at the topology.
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.
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
Flicker, which is the electrolytic in the driver, or one LED in a series string opened.
Before you open it
Do this while it is still unplugged, cool, and not leaking. Unplug. Confirm it is LED and not a CFL. CFLs contain mercury and stay intact.
Where the dead machine usually is
- Living room and entertainment stack — In the house
- Kitchen — In the house
- Junk drawer and cable box — In the house
The closet of dead bulbs.
How it comes apart
The diffuser pops. The driver is often potted. If it is potted, take the LED board if it is socketed and recycle the rest.
Tools: Spudger, Meter, A way to defeat the potting, which is often not worth it.
Words on this page
- mains
- Ordinary household wall power. It can kill. Unplug before you open anything that used it, and do not experiment on live wiring.
- isolated
- The low-voltage side is not electrically connected to the wall. A proper brick usually is. Many cheap lamp boards are not.
- electrolytic
- A common type of capacitor with a polarity. The stripe marks the negative lead. A bulging top means it has failed.
- series
- Connected in a chain. Cells in series add their voltages. LEDs in series all go dark if one of them opens.
What to take
The table is the short version. The notes under it describe that part inside this machine, not only the general description.
| Part | Call | How many | How often | Where to look |
|---|---|---|---|---|
| LED array or COB | Worth pulling | 1 | usually | Under the diffuser. |
| LED constant-current driver | Bonus | 1 | usually | In the base. |
| Electrolytic capacitor | Bonus | 1 | usually | In the driver. |
| Bridge rectifier | Bonus | 1 | usually | Input. |
| Enclosure | Leave it | 1 | always | The shell. |
Worth pulling
Series LEDs on aluminum.
Under the diffuser.
One black LED opens the string.
Mixed.
Bonus
May be a capacitive dropper. Isolation-check before the output touches anything else.
In the base.
If there is no transformer, it is not isolated.
The cap is the usual failure.
This is the part that dried out.
In the driver.
Do not reuse it.
Bad.
Four diodes.
Input.
Only if you enjoy desoldering.
Fine.
Leave it
A base and a diffuser.
The shell.
Not an enclosure you wanted.
Fine.