Hot Fuse, No Display [Fixed] reboot set brightness [Fixed]

[billmorton]

a good friend of mine bought the Ice Clock for me as a Christmas gift, and I decided to put it together last night. Everything was going great, all of the tests (beeps) and voltages were good at the various stages until I mounted the ICs and glass tube. When nothing was showing up, I noticed the fuse capacitor was very warm, and figured I had a problem. I tried removing the tube and two IC sockets, and noticed that when I remove the long IC the voltages on the 7805 are correct again, and the fuse is not hot, however, I no longer get the start-up beep, and the voltage on the Diode is low (I think around 20V). Can you take a quick look at these pictures and let me know if you see any issues, or have a place to start checking?

There was one thing the directions were not super clear on ... there is a diode that is very close to one of the contacts for the high voltage transistor that ended up getting solder bridged on the back, but it looked like the directions had it that way as well.

Large Pictures of my handy work: (use links for original sized images)

http://www.smugmug.com/gallery/10725733 ... 8XSmS-O-LB


http://www.smugmug.com/gallery/10725733 ... XEcQg-O-LB

Thanks in advance everyone, and Ladyada, you rock! P.S. That fuse capacitor is genius.

[adafruit]

remove the VFD chip and the microcontroller. wait 5 minutes. then test the 9V and 5V supply
then insert the microcontroller. test the 9V and 5V supply
what are those voltages?

[billmorton]

With the Micro controller and VFD chip removed the voltages on the power regulator were 9.05v and 4.99v and the fuse was cool.

With the micro controller installed the voltage was dropping, I'll have to check again but it was something close to 3v and 1v though the numbers were decreasing.

There may be an ever so slight chance that my probe slipped under the circuit while I was waiting for the voltage to drain, which takes forever if you just unplug the transformer and don't disconnect the jack from the board. The wall wart must have some capacitors inside as well. I don't think it shorted anything, but in the interest of full disclosure it may have happened.

[adafruit]

and it beeped, at least once?

[billmorton]

and it beeped, at least once?

Yes, it did beep (twice even). The second time when checking the boost converter.

The next time I plugged it in was after adding the tube, and nothing.

[adafruit]

the chip is likely damaged, but we think it may have been damaged by the tube if there were shorts in the tube wiring. check if the tube is assembled properly. then go through and resolder any iffy joints.
finally, you can order a new chip from us, email [email protected] with a link to this message

[billmorton]

the chip is likely damaged, but we think it may have been damaged by the tube if there were shorts in the tube wiring. check if the tube is assembled properly. then go through and resolder any iffy joints.
finally, you can order a new chip from us, email [email protected] with a link to this message

Thanks much, I will post pictures of the tube & wiring tonight when I get home.

Any other voltages / areas I should check ?

[adafruit]

not really, its almost certainly a broken chip :<

[billmorton]

Ok, Followup ....

The new Microcontroller fixed the problem - the unit now beeps and the display lights up, all functions are working EXCEPT when I try to increase the brightness the whole thing reboots after some sort of funky digits on the display. I can enter the menu, set time, date, 24/12hr, but when I get to set brightness, it starts at '30' and I hit the + key and some random segment gets brighter briefly then the whole clock reboots.

I have had it running the past few minutes and it rebooted on it's own once as well. The only thing I have not done on this project is to install the backup battery.

Help?

[adafruit]

did you ever install C10?

[billmorton]

Good eyes!

I just checked, and it is missing. I must have misplaced it since I didn't end up with any spare parts, but I will scrounge around for a 0.1uf ... does it have to be exact, or is there some leeway?

P.S. There should be a donate link to "buy an engineer a beer" or whichever beverage you prefer I appreciate all the help.

[adafruit]

0.1uF or higher - dont go any lower

[billmorton]

0.1uF or higher - dont go any lower

It Works!!!

I sorted through a ton of capacitors in my junk box and couldn't come up with .1uF. Then out of the corner of my eye I saw the digg button stuck on the refrigerator. I ripped it off and found that it had a 104 =) Poor digg button, I will rebuild you some day.

I'll try to get some nice pictures of the clock in action, and post them as thanks for the help.

[adafruit]

the digg button can live without it

[billmorton]

Pictures!
Shutter speed must have been too fast and caught the seconds taking a break

Click links for very high resolution versions


http://www.smugmug.com/photos/764528463_7PnYc-O.jpg

http://www.smugmug.com/photos/764528646_viKNZ-O.jpg

http://www.smugmug.com/photos/764528803_bXkCG-O.jpg