I have just been given an LED lamp (an Xmas gift for a relation) bought from a cheap Supermarket Chain that went "poof" when first switched on. I'm a bit of a noob, but here, attached, is the Shenzhen spec sheet for the main part, ICL1103, modified in red to show how the PCB has actually been wired (on a thick aluminum backed board with exposed tinned tracks, it was very hard to de-solder!). The MB6S bridge is shorted across the terminals as indicated, the component values are as stated, and the 750k resistor appears to be / is in the wrong place, however 240v / 750K = 320uA, is not going to blow the fuse, (I think it is 10mA, or 100mA, Brown, Black, long space, Black!). The Capacitor is OK. So, any ideas what went wrong please? If I replace the bridge, and fuse, will it work again? Yes, I know, it was cheap, but I do like to re-cycle.
Delta Prime
- Jul 29, 2020
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I don’t think so .. your MOV would no longer exist.
Whatever floats your boat, brother!Please no more relations with an LED lamp; go with incandescent lamps it’ll handle your load.Hehe.
Don't think so. I'd guess it's there to discharge the cap safely in the event of the current-limiter IC failing open-circuit.
Martaine2005
- May 12, 2015
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Check the LED driver for a short across GND and Vout. Only if the link with missing’ Resistor is still present.
If it’s ok, then only the bridge rectifier can be the culprit. Assuming the capacitor is definitely ok.
But check the LEDs too.
OP labelled the schematic as “not present “.
If it’s ok, then only the bridge rectifier can be the culprit. Assuming the capacitor is definitely ok.
But check the LEDs too.
It doesn’t exist
OP labelled the schematic as “not present “.
Thank you @Martaine2005 .Check the LED driver for a short across GND and Vout. Only if the link with missing’ Resistor is still present.
If it’s ok, then only the bridge rectifier can be the culprit. Assuming the capacitor is definitely ok.
But check the LEDs too.
It doesn’t exist
OP labelled the schematic as “not present “.
Vout-GND is 10.6Mohm and Vout-+ve is 12.1Mohm.
The upper ac-in on the bridge to -ve is 0ohm (out of circuit).
The lower ac-in on the bridge to +ve is 0ohm (out of circuit).
Across the LEDs measures open circuit, cap is definitely OK.
Why did the fuse (and the bridge?) go "poof", there is no short (now), unless it was the bridge?
I'm thinking maybe I could patch in some readily available diodes to make a bridge and test it out? (LOL?)
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Delta Prime
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You’re too kind! thank you my friend for the correction!It doesn’t exist
+1
ahsrabrifat
- Jan 18, 2025
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You already have many insightful observations regarding your attached circuit diagram. I hope you'll fix the lamp soon. However, if you want to make a portable LED lamp by yourself, you can find these sources helpful.
dimmable LED lamp - Share Project - PCBWay
With this powerful lamp you can regulate the intensity of light you need with the help of a LM2596 stepdown module and with the PWM regulato
www.pcbway.com
Delta Prime
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So have you! You have made comments to help others I think it is time for you to introduce yourself. This is a community. I have been corrected many times which is a wonderful thing. We all do it with the best of our ability so who the hell are you?
Also drop the AI crap you’re better than that; my personal observation.
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Martaine2005
- May 12, 2015
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Of course you can make your own bridge with diodes.
1N4*** series diodes will be perfect.
Also, the bridge rectifier shorting will instantly activate the fuse (blow).
1N4*** series diodes will be perfect.
Also, the bridge rectifier shorting will instantly activate the fuse (blow).
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