Is this component burnt? (photo attached) Trying to fix a lava lamp.

[ContraHacker]

Hi all.

 

A beginner here. I'm trying to fix this lava lamp and I noticed this three-legged component kinda molten-ish inside the on-off knob. There is a brown tint underneath the PCB too. I have two questions:

 

(1) Is this thing bad? aka. will replacing it do the job?

(2) Do I even need this PCB? Can I directly plug it into the mains AC?

 

This knob seems to only turn the lamp off or on. I don't see the lamp getting dimmer by turning the knob. Better to ask before committing arson on my own house.

 

The bulb is fine. Its an E14 R39 rated for 30W.

[Helpful Tech Witch]

if you didnt need the pcb, it wouldnt be there......

[ContraHacker]

2 minutes ago, HelpfulTechWizard said:

if you didnt need the pcb, it wouldnt be there......

Given that it came from China where cost cutting is the name of the game, and my Dad said the same thing; I should have thought of that on my own. Anyway, would you recommend replacing this burnt component, or the entire PCB?

[Latvian Video]

10 minutes ago, ContraHacker said:

The component is blown, from googling, I have found that it is a "MAC 97A6 m922" 

[Latvian Video]

1 minute ago, ContraHacker said:

Given that it came from China where cost cutting is the name of the game, and my Dad said the same thing; I should have thought of that on my own. Anyway, would you recommend replacing this burnt component, or the entire PCB?

If everything else looks fine, not burnt and has the correct values when measured with a multimeter, I would just replace the component and see what happens, if it breaks, it isnt that bad, because you can get a pack of 50 for 4USD from ebay

[ContraHacker]

1 minute ago, Latvian Video said:

If everything else looks fine, not burnt and has the correct values when measured with a multimeter, I would just replace the component and see what happens, if it breaks, it isnt that bad, because you can get a pack of 50 for 4USD from ebay

Seems reasonable. I'll get some 'MAC 97A6 M922's I guess and give it a shot. Thanks a lot!

[Latvian Video]

Just now, ContraHacker said:

Seems reasonable. I'll get some 'MAC 97A6 M922's I guess and give it a shot. Thanks a lot!

No problem, I suspect it might have blown because I think the heat is high under the lamp

[mariushm]

You have a potentiometer, which is probably used to adjust brightness or something like that. That 3 part pin is probably a transistor - by adjusting the potentiomenter, the transistor probably varies the amount of current going through it (ex the transistor adjusts current between 0.1A and 1A

 

You should get a multimeter, set it on resisance and put the probes across the terminals of the potentiometer. 

Look at the meter and slowly turn the potentiometer .. you should see the resistance go up and down as you turn the potentiometer.

You want to make sure there's no "dead zones" - basically areas in the rotation of the potentiometer where the potentiometer will fail and give no resistance (it can happen when the material on the circuit board inside the potentiometer gets corroded or breaks down and the contact moving above that material loses connection)

If the potentiometer is used as variable resistance to control how much current that transistor receives, then if transistor fails the transistor could open too much and overheat.