Author Topic: Onboard LED Display Not Working  (Read 1566 times)

Offline Mickpat

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Onboard LED Display Not Working
« on: August 03, 2010, »
I just completed my first board!  When I power the board up, it displays the welcome message, but the center LED segment doesn't work.  I swapped the LED with the one to the left and have the same issue.  Everything else works so far.  When I enter test mode, the left and right LED segments display and then the 16 LEDs on the board count up.  I can set the channel number, but can't see the second digit.   I checked the solder connections of the socket and the adjacent chip and I don't see anything wrong, but given my soldering skills, this is most likely where I made the mistake.  Any ideas? (I can't wait to start board number two now that I know what to do.)

Offline rrowan

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Re: Onboard LED Display Not Working
« Reply #1 on: August 03, 2010, »
Did you try removing the led driver chip and check for bent pin?

along with solder problems

Cheers

Rick R.
Light Animation Hobby - Having fun and Learning at the same time. (21st member of DLA)
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Warning SOME assembly required

Offline RJ

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Re: Onboard LED Display Not Working
« Reply #2 on: August 03, 2010, »
Did you forget your tiny little 2700uf capacitor that is stuck between the big wide chip SAA1064 and the display leds? If you leave it off or miss soldering it you will get this. It controls the multiplexing of the display and if it is not then only some of the display lights.

RJ
Innovation beats imitation - and it's more satisfying

Offline Mickpat

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Re: Onboard LED Display Not Working
« Reply #3 on: August 03, 2010, »
I did forget to install the 2700uf capacitor.  It is working now.  Thank you so much!

Michael

Offline RJ

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Re: Onboard LED Display Not Working
« Reply #4 on: August 03, 2010, »
Glad to be of service to you.

RJ
Innovation beats imitation - and it's more satisfying

Offline rrowan

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Re: Onboard LED Display Not Working
« Reply #5 on: August 03, 2010, »
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Did you forget your tiny little 2700uf capacitor that is stuck between the big wide chip SAA1064 and the display leds? If you leave it off or miss soldering it you will get this. It controls the multiplexing of the display and if it is not then only some of the display lights.

RJ

Oh sure the 2700uf cap trick

I missed that one  ;D  <res.

btw: Congrats Michael getting the LE fully working

Cheers

Rick R.


Light Animation Hobby - Having fun and Learning at the same time. (21st member of DLA)
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Warning SOME assembly required

Offline n1ist

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Re: Onboard LED Display Not Working
« Reply #6 on: August 04, 2010, »
Actually, 2700pF (aka 2.7nF), not 2700uF.
/mike

Offline jnealand

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Re: Onboard LED Display Not Working
« Reply #7 on: August 05, 2010, »
details details. 

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Actually, 2700pF (aka 2.7nF), not 2700uF.
/mike

Jim Nealand
Kennesaw, GA