Adafruit #570 in Inc 5000 & #11 in manufacturing - fastest-growing private companies in America - INC 5000 - Read more!

Ice Tube Clock - No Beep

by sensae on Tue Apr 23, 2013 11:58 pm

I've been assembling the Ice Tube Clock kit, and I've ran into an issue. At the appropriate time in the instructions I turned on the board and it sounded the boot beep, and again when I was verifying a high voltage at the zener diode it beeped just fine. After installing the VFD and the rest of the components to drive it, I no longer get a boot beep, and the center of the display glows dimly. I've removed the VFD assembly and the chip from the PLCC socket , but it still won't boot.

I've verified 9V from the DC adapter, and 4.7V both from the 7805 and at the V+ pin on the ATMega. I'm not sure where to troubleshoot from here. Here's what my board looks like.

http://imgur.com/a/gft91
sensae
 
Posts: 10
Joined: Sun Apr 14, 2013 8:02 pm

Re: Ice Tube Clock - No Beep

by adafruit_support_bill on Wed Apr 24, 2013 5:19 am

Are you still getting high voltage from the boost converter? You must have had it at one point to light the tube.

From what I can see in the photos, the solder looks OK. But more detail would be good. Try near a window or even outside for better light.
User avatar
adafruit_support_bill
 
Posts: 28856
Joined: Sat Feb 07, 2009 9:11 am

Re: Ice Tube Clock - No Beep

by sensae on Wed Apr 24, 2013 3:45 pm

The first time I tested the boost converter, I heard a boot beep and read ~55V off the zener diode. After assembling the rest of the kit, the boost converter doesn't appear to be working anymore. I read around 8.5V from the zener diode, regardless of whether the PLCC or VFD are installed.

I read the same voltage going in to the tube, around 8.5V, which makes it glow dimly. I've attached some more pictures, hopefully these are clearer.

http://imgur.com/a/haGAq
sensae
 
Posts: 10
Joined: Sun Apr 14, 2013 8:02 pm

Re: Ice Tube Clock - No Beep

by adafruit_support_bill on Wed Apr 24, 2013 3:56 pm

The lack of both startup beep and boost voltage indicates that the processor is not running. What puzzles me is that the tube is lighting up on that voltage. Usually, no boost means no light.

Other than that, it looks like a good clean build so far. Lets assume this is a case of infant mortality and replace the processor. Contact support@adafruit.com with a link to this thread and ask for a replacement Ice Tube processor.
User avatar
adafruit_support_bill
 
Posts: 28856
Joined: Sat Feb 07, 2009 9:11 am

Re: Ice Tube Clock - No Beep

by sensae on Mon Apr 29, 2013 8:25 pm

You were right to replace the microcontroller, my clock boots and beeps now. However, the display starts out fully visible and slowly most of the segments will flicker out. I've inspected my soldering with a 20x loupe and it all looks fine, and if I short JP2-2 to GND the tube lights up just fine. I think I may be experiencing some kind of issue with Q3.
sensae
 
Posts: 10
Joined: Sun Apr 14, 2013 8:02 pm

Re: Ice Tube Clock - No Beep

by adafruit_support_bill on Tue Apr 30, 2013 4:56 am

What voltage do you measure at R3 when the display fades out?
User avatar
adafruit_support_bill
 
Posts: 28856
Joined: Sat Feb 07, 2009 9:11 am

Re: Ice Tube Clock - No Beep

by sensae on Tue Apr 30, 2013 8:04 pm

I read 2V on R3. When I bridge GND to R3 with my digital multimeter, the display flicker disappears and the clock seems to work fine, until I remove my probe.
sensae
 
Posts: 10
Joined: Sun Apr 14, 2013 8:02 pm

Re: Ice Tube Clock - No Beep

by adafruit_support_bill on Wed May 01, 2013 5:17 am

I agree. Sounds like Q3 is not working right. Contact support@adafruit.com with a link to this thread for a replacement Q3.
User avatar
adafruit_support_bill
 
Posts: 28856
Joined: Sat Feb 07, 2009 9:11 am

Re: Ice Tube Clock - No Beep

by sensae on Tue May 07, 2013 9:10 pm

Unfortunately, after replacing Q3 my clock is still suffering from the same symptom - display works fine when I touch GND and Q3 with my DVM, but otherwise I read 2V on R3 and most of the display doesn't light.
sensae
 
Posts: 10
Joined: Sun Apr 14, 2013 8:02 pm

Re: Ice Tube Clock - No Beep

by adafruit_support_bill on Wed May 08, 2013 5:18 am

What voltage do you measure on pin 13 of the Atmega chip? Double check the resistor values for the battery sense circuit (R1 & R2).
User avatar
adafruit_support_bill
 
Posts: 28856
Joined: Sat Feb 07, 2009 9:11 am

Re: Ice Tube Clock - No Beep

by sensae on Tue May 14, 2013 12:49 am

I read 1.18V on pin 13 of the Atmega, and I've verified that R1 and R2 are installed correctly.
sensae
 
Posts: 10
Joined: Sun Apr 14, 2013 8:02 pm

Re: Ice Tube Clock - No Beep

by adafruit_support_bill on Tue May 14, 2013 6:50 am

1.18v is a little low. It should be 1.22v or more. That pin is connected to a voltage divider to detect when the power fails and the battery kicks in. If it goes below the bandgap reference voltage (nominally 1.1v, but could be as much as 1.2v) it will turn off Q3 to cut power to the tube.

What is the output of the voltage regulator when the display cuts out? (should be 4.5v or more).
Does the display come back on if you jumper pin 13 to 5v?
User avatar
adafruit_support_bill
 
Posts: 28856
Joined: Sat Feb 07, 2009 9:11 am

Re: Ice Tube Clock - No Beep

by sensae on Tue May 21, 2013 2:49 am

The output of the voltage regulator is a steady 4.95V, and bridging 5V to pin 13 has no effect.
sensae
 
Posts: 10
Joined: Sun Apr 14, 2013 8:02 pm

Re: Ice Tube Clock - No Beep

by adafruit_support_bill on Tue May 21, 2013 5:36 am

We've had several reports of fading displays similar to yours recently. Enough to make me think it is more than a coincidence.
I read 2V on R3. When I bridge GND to R3 with my digital multimeter, the display flicker disappears and the clock seems to work fine, until I remove my probe.

What mode is your multimeter in when you do that test? Voltage measurement?
What happens if you run a jumper wire from the Q3 side of R3 to 5v?
User avatar
adafruit_support_bill
 
Posts: 28856
Joined: Sat Feb 07, 2009 9:11 am

Re: Ice Tube Clock - No Beep

by sensae on Tue May 21, 2013 5:15 pm

It's in voltage measurement mode. When I run a jumper wire from the Q3 side of R3 to 5V, the display illuminates perfectly.
sensae
 
Posts: 10
Joined: Sun Apr 14, 2013 8:02 pm