Created March 07 2010
Updated Sept 08 2010

The LED Upgrade Page

What does this page mean to me?
With the information on this page, you should be able to purchase the components necessary to install/upgrade a LED
I'll show you how I upgraded some incandecent bulbs with LED bulbs for a stereo system
With a few simple calculations, you can purchase/install/upgrade to LED's and relax knowing your job will last a long time

Why upgrade to LED?
LED's last a long time and use very little current
In my case, a stereo lighting repair required 2 hours of dissassembly just to get to some burned light bulbs
I planned ahead so I dont have to do that again

Why not just chuck it and buy another?
I'm not into this disposable society thing, it's totally unsustainable
Sentimentality, environment, learning ... all good reasons to keep stuff out of landfills

Replacing Incandecent with LED's - Step by Step
This story first started what must be 10 years ago.  A good friend of mine asked me to repair his stereo.  It was a Magnavox AS640 all in one thingy

I remember I had fixed a stereo but I had totally forgotten about how much work was involved in taking it apart

I did not think of creating this page until I far after the dissasembly so i missed the chance to take a few pictures  :-(

The problem with the unit back then is the display is illuminated with 2 incandecent bulbs
The bulbs are below the soldered display and a plastic diffuser

Bulbs with filaments eventually burn out it seems
I had originally removed the board, desoldered the display and simply replaced the bulbs
Well here we are many years later with a repeat of the problem
The cool thing is we now have these amazing LED's available
In theory I've read it will last 100,000 hours

Here comes the technical part
The existing bulbs used 12 Volts DC
I was planning to use a White LED
I went to the very excellent Sayal Electronics ( and purchased the following

To me this means a 5 millimeter, white LED with 5000 millicandela
I wanted a slight brighter one but they were out of stock
This whole MCD thing gets kinda interesting with respect to viewing angle
For my application, 5000 MCD worked excellent

I visited the very excellent "LED Wiz" by Rob 'linear' Arnold at
With a 12 Volt DC source, White 3.3 Volt White LED at 20ma, my current limiting resistor is 470 Ohms
I decided to play it a little safer and went with a slightly higher resistance of 510 Ohms
This way the light output was so miminally smaller and the LED wont get as hot
I recommend you play with your resistance value outside of the repair job before you commit to it

I did not want to have a huge dissassembly in the near or perhaps far future
I decided to modify the plastic housing slightly to allow the new LED bulbs to be inserted externally
I simply used longer wires to power the bulbs rather than solder them under the display as originally designed
This way I no longer have to do a complete dissassembly of the board and desolder the display
Here's a picture of the modified plastic assembly, power wires, heat shrink covering the resistor and LED
I used a hot glue gun to fix the wires so the LED's created a nice diffused light under the diffuser
Oh yah, the LED's were clear, I sanded the surface to add to the diffusing aspect  :-)  hopefully they dont get too hot as a result

Here's the backside.  I know it's not perty.  It's electically sound for future repair.  I dont care too much about it looking beautiful

Here's what the display looks like now, not bad

These bulbs a so bright, even with only 18 milliamps Wow

Voila, it's back in action

In July of 2010, I received a request for assistance on another Magnavox AS640
I offered to modify the board for a reasonable price
It was a risky venture on the part of the owner but well worth the satisfaction of keeping something out of the landfill
I'm still waiting for a final status update

Here's a picture of several items piled together from this unit

It outlines the heat damage to the diffuser, circuit board and plastic housing
It's pretty amazing these things did not catch fire in the field

Please show me some LED related links
Notes on LED's
"LED Wiz" by Rob 'linear' Arnold

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