I recently purchased a TV-B-Gone kit version 1.2.
A component had not been included in the kit but it was quickly sent it to me.
My husband is a former IBM engineer and well acquainted with breadboarding and soldering.
He assembled the kit according to instructions and got to the first test.
He inserted the batteries. The green led did not come on.
Again, according to instructions, he checked the polarity of the led and made sure that the microcontroller was inserted properly. The dot was difficult to see but it was there.
The batteries were fresh.
According to his diagnosis, the microcontroller is either not programmed correctly or defective.
What now?
Test Failed. What's Wrong?
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- adafruit_support_bill
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Re: Test Failed. What's Wrong?
If you post photos of the front & back of the board we can double-check your assembly.
Also, if you have a meter, measure the voltage between ground & the '+' leg of the LED.
Also, if you have a meter, measure the voltage between ground & the '+' leg of the LED.
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Re: Test Failed. What's Wrong?
Ok, my husband measured the voltage between ground and the positive side of the green LED. It measures slightly more than 2 volts. (2v).
I've taken pictures of the board. How do I post photos?
I've taken pictures of the board. How do I post photos?
- adafruit_support_bill
- Posts: 88093
- Joined: Sat Feb 07, 2009 10:11 am
Re: Test Failed. What's Wrong?
Hmm. Looking at the schematic, the positive side of the LED should be at VCC. What do you measure across the battery terminals?
You can post photos using the "Upload attachment" tab below the edit window.
You can post photos using the "Upload attachment" tab below the edit window.
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Re: Test Failed. What's Wrong?
Here are the photos.
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- DSC02177.JPG (726.45 KiB) Viewed 2385 times
- adafruit_support_bill
- Posts: 88093
- Joined: Sat Feb 07, 2009 10:11 am
Re: Test Failed. What's Wrong?
On the back side, there are some problems with the soldering. You need to solder all 8 legs of the microprocessor socket. You have 4 with little or no solder and 2 that could use more. Also, some of your solder joints have a 'frosty' appearance indicating that the solder didn't flow properly (a 'cold joint'). Use a clean hot iron and re-flow any joints that are not smooth and shiny. If you are using a low-powered iron (<25 watts) you should pause a bit between joints to let it heat up again.
On the front side, your microcontroller is in backwards. Powering it up this way may have damaged the processor, but fix up the soldering and turn the microcontroller around and test it again. If you can't get it going, we do have replacement microcontrollers in the store.
Excellent photos by the way I wish they were all that well lit and focused!
On the front side, your microcontroller is in backwards. Powering it up this way may have damaged the processor, but fix up the soldering and turn the microcontroller around and test it again. If you can't get it going, we do have replacement microcontrollers in the store.
Excellent photos by the way I wish they were all that well lit and focused!
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- Joined: Mon Oct 24, 2011 6:06 pm
Re: Test Failed. What's Wrong?
Well, my husband says to order another microcontroller, so I will do that.
He said to please be sure the dot that helps orient the microcontroller is visible, because it was a pinprick before and he could barely see it.
I would like to ask you--how can you tell it is upside down from this photo? If I know that, I'm sure we can get it right this time!
I guess we should have assembled it as a team effort. My husband is the electronics guy--but I have better eyes!
Thanks for your help.
He said to please be sure the dot that helps orient the microcontroller is visible, because it was a pinprick before and he could barely see it.
I would like to ask you--how can you tell it is upside down from this photo? If I know that, I'm sure we can get it right this time!
I guess we should have assembled it as a team effort. My husband is the electronics guy--but I have better eyes!
Thanks for your help.
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- Posts: 5
- Joined: Mon Oct 24, 2011 6:06 pm
Re: Test Failed. What's Wrong?
I could be missing the obvious here. Is the dot my husbands talks about that indentation in the lower left corner? If so, can I assume it goes in the upper right corner?
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Re: Test Failed. What's Wrong?
thats right!Joanne wrote:I could be missing the obvious here. Is the dot my husbands talks about that indentation in the lower left corner? If so, can I assume it goes in the upper right corner?
Please be positive and constructive with your questions and comments.