Green LED does not flash

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robrlstn
 
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Green LED does not flash

Post by robrlstn »

Bought TV-B-Gone Kit v1.2 from MakerSHED.

Green LED does not flash at partial assembly test point. All solder connections look good. Chip has correct orientation as does the green LED and the power wires. With chip and batteries removed, jumping out power from a Jameco LED tested shows green LED as OK. The battery power is getting to the microcontroller pins as measured by voltmeter (pin 8 positive, pin 4 ground).

I assume the chip is programmed since the anti-static bag says adafruit.  I have visited the forums and read the FAQ. There possibly might be a batch of bad chips?

Is there a way to attach an old scope (Tek 2215) without loading the circuit down too much to see if the resonator is resonating?

adafruit
 
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Re: Green LED does not flash

Post by adafruit »

sure, email support@adafruit, we'll get you a new chip

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robrlstn
 
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Re: Green LED does not flash

Post by robrlstn »

Got a new microcontroller in the mail from Adafruit. THANK YOU!

Still does not work. So I breadboarded the chip, an LED, a current limiting resistor, and a 4MHz resonator which I had. Didn't bother with the filter caps.

At 5 volts from a regulator or 3 volts from batteries, both chips flash the LED quickly 3 times and then flash approximately 115 times, so it looks like both chips are good and going through the expected sequence.

Later this week I will try to closely examine the pc board, trace by trace, looking for opens or shorts. If no problems found, then I will look to buy an 8MHz resonator.

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robrlstn
 
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Re: Green LED does not flash

Post by robrlstn »

Well, this is embarrassing, yet pleasing too. The green LED gets its Vcc from the top of the board. From the bottom the solder joint looked OK to me but upon re-soldering it, it now works. So the entire problem was that I was getting no visual feedback.

Sorry for the trouble. I'll finish building it and see what happens.

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robrlstn
 
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Re: Green LED does not flash

Post by robrlstn »

Finished kit tonight, turned my TV off. Thank you.

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Re: Green LED does not flash

Post by adafruit »

great!

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