Duratech 5 Diopter LED Illuminated Magnifying Lamp : Burnt resistor

[Majorphill]

Hi

I have one of these with a burnt resistor (the only one).

I am unable to read the bands and can not find a circuit diagram.

Does anyone know what it may be or alternatively who manufactures the Duratech brand so that I can ask them direct.

Thanks in advance

 

[davenn]

Hi

I have one of these with a burnt resistor (the only one).

I am unable to read the bands and can not find a circuit diagram.

Does anyone know what it may be or alternatively who manufactures the Duratech brand so that I can ask them direct.

Thanks in advance

post a photo or link to one so we can see the one you are talking abt
it may be the same as one I have here and I can open it up and look for you

 

[Majorphill]

Davenn

Thanks for the reply

Duratech 5 Diopter LED Illuminated Magnifying Lamp

All I can see is a dark band at each end.

Regards

 

[davenn]

Davenn

Thanks for the reply

Duratech 5 Diopter LED Illuminated Magnifying Lamp

All I can see is a dark band at each end.

Regards

OK looks real similar to mine ... it came from Altronics instead

so do you have a photo of the circuit board so I can see if it is the same and which resistor you are talking about ?


Dave

 

[Majorphill]

Dave
The item is at my workshop. I shall take a photo today and post this evening (Ausralian Time).
It could well be a generic bran marketed under many names.... Duratech, Velleman, Rhino etc
Thanks for your help
Phil Major

 

[Majorphill]

Dave

Here we go. As you can see my photographic skills are not great.

The area to the upper right had the blown resistor.

I suppose the next question is why it blew. I had been using the light for an hour or two when the LEDs went very dull.

Again

Thanks for your help

Phil Major

 

[davenn]

The area to the upper right had the blown resistor.

I suppose the next question is why it blew. I had been using the light for an hour or two when the LEDs went very dull.

slightly different to mine but basically the same process
240V in phase through a fuse inside heatshrink ( lower left on your first photo)
mine doesn't use that large input capacitor, tho there is holes in t he PCB where it could go

then mains goes to a bridge rectifier ... probably under that large cap on your board.
the output of the bridge rectif has an electrolytic cap across it, mine is a 2.2uF 400V rating
you one looks like the cap is bulging at the top and is close to blowing --- it may be the main reason for the overall failure
mine doesn't have that resistor in the output, tho again there are holes in the pcb where it could go

The ring pcbs that have the LEDs on them have a number of 1W 900 Ohm resistors

 

[Majorphill]

Dave

You are a gentleman

Thanks for that.

My light doesn't work without the resistor and barely worked with the blown one in.

Maybe I'll take a punt and replace the missing one with another 1W 900 Ohm resistor. I can't do more than keep it not working.

I noticed the cap looked swollen as I posted the photos but didn't notice it when I was looking at the board. I shall look more closely tomorrow. I shall look for those ring pcbs.

This is a great resource and I am going to be an avid follower as I try to learn a little more.

Many thanks

Phil Major

 

[bradmaarssen]

Dave

You are a gentleman

Thanks for that.

My light doesn't work without the resistor and barely worked with the blown one in.

Maybe I'll take a punt and replace the missing one with another 1W 900 Ohm resistor. I can't do more than keep it not working.

I noticed the cap looked swollen as I posted the photos but didn't notice it when I was looking at the board. I shall look more closely tomorrow. I shall look for those ring pcbs.

This is a great resource and I am going to be an avid follower as I try to learn a little more.

Many thanks

Phil Major

Did you have any luck with your lamp? I have the same one with the same problem.