Ice Tube Clock (Tube has no display)

[fmaznicki]

My Ice Tube clock has no display whatsoever from the Tube. Processor beeps once when i plug it in and all voltages seem normal.

I've redone all the solder points, checked part placement and everything looks good. I'm at a loss here maybe someone can shed some light on my situation The only thing i could possibly suspect is wiring of the tube or bad tube, but i'm fairly certain that the 3 wires are placed in the correct arrangement.

Thanks for your help!

http://imgur.com/a/34SCc

[adafruit_support_bill]

Looks like you have the 3 "NC" leads on the tube correctly aligned. The photos of the main board are a little dark. Can you get a closer shot of the VFD-end of the board with more light (outside, or near a window usually works well). Can you post a photo of the solder-side of the tube-board too?

[fmaznicki]

I've added your requested pictures to my album.

Thanks for your quick response. much appreciated!

[fmaznicki]

I did a continuity test on all the pins going to the tube, seems like VBIAS (pin2) is shorting out to ground? does this sound like a problem?

[adafruit_support_bill]

Vbias shorting to ground would definitely explain no display. Have yo localized the short to the tube-board (do you see a correct bias voltage on the main board when the tube is not installed)?

You solder joints have a bit too much solder, but I don't see any obvious shorts in the photos. Inspect both sides of the tube board carefully for potential solder-bridges. It looks like a fair amount of solder has flowed through to the tube-side of the board and the short could be there too.

[fmaznicki]

VBIAS voltage without mini-pcb installed is a solid 4.65 volts, when i install the tube, VBIAS voltage drops to less than 1v so it is localized to the mini-pcb/tube. I suspect an internal short on the tube, i've reinspected all the solder joints and none of which are bridged. My solder joints were perfect the first time before I got frustrated and just added more solder (lesson learned don't keep added solder out of frustration) Is there anything else I should test to verify if it's the tube or board, seems too coincidental to be the board since it's only the VBIAS and i don't have a desoldering gun to detach (next purchase eh) ?

Thanks again, this project has been a lot of fun and i'm already looking into my next project from you guys, your site/support is really a fantastic!

[fmaznicki]

Actually, scratch that. I'm getting 14 ohms, maybe that's normal? I was just going off the fact that it was making my multimeter beep with a continuity test. but still voltage that low seems odd no?

[adafruit_support_bill]

14.0 ohms between bias and ground? That is exactly what I measure on a working tube that I have here. The bias is a heater wire inside the tube. Due to the low resistance, the voltage will drop when the tube is installed.

What do you measure for the boost voltage when the tube is in place?

[fmaznicki]

Boost voltage fluctuates around 12.8 and 12.9 when the tube is hooked up

[fmaznicki]

and yes 14 ohms between vbias and ground.

[adafruit_support_bill]

The 14 ohms sounds normal, but the voltage drop you are seeing is more than what I measure on my Ice Tube here on the bench. I get just over 3v on VBias when the tube is installed. What do you measure on the 5v leg of the voltage regulator with the tube installed?

[fmaznicki]

0 in the middle, 4.9 on left (inward on the board) and 8.58 on the right (closest to the edge of the board)

[jarchie]

It's kind of a long shot, but cleaning the both circuit boards might be worth a try.

I built my second Ice Tube Clock using the Adafruit lead free solder and it didn't work. After scrubbing away the rosin buildup, everything worked perfectly. When the same thing happened on two additional projects, I started habitually cleaning my boards.

(Please note that I'm an Adafruit customer, but am otherwise unaffiliated with Adafruit.)

[adafruit_support_bill]

4.9 on left (inward on the board)

That's a little toward the low-end of normal. But that could be your meter too. Might want to check the batteries. In any case, 4.9v should still be sufficient to run the clock.

Jarchie's suggestion is worth a try. Burn't flux can be conductive and cause problems. You can usually find 90% or better isopropyl alcohol in a drug-store and scrub the board with an old toothbrush. It will take a few passes to get rid of the residual stickiness. Let everything dry thoroughly before re-powering the board.

[fmaznicki]

Thanks Jarchie for your suggestion.

Well, she's clean as a whistle now. Still posts (beeps) so processor is still coming online after the cleanup, but still no dice. I'm still getting 4.9 on the regulator.