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Ice Tube Clock Transistor Related Display Issue
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Ice Tube Clock Transistor Related Display Issue

by crashkaboom on Tue Dec 29, 2015 4:29 pm

I purchased an Ice Tube kit from Massdrop last year and finally had a chance to assemble it today. After powering up the completed clock, I get a beep and only one segment of the second (from the left) digit is illuminated. After searching this forum, I double checked my display-related joints, cleaned the PCB and reseated the controller chip to no avail. Ultimately, I managed to get it to display properly by jumping the outer pins on Q3 as mentioned by jarchie in this thread: http://forums.adafruit.com/viewtopic.php?f=41&t=54952#p277845. I understand this isn't a permanent fix, and I was wondering if Adafruit could assist with this issue. I have attached images of the completed clock with the jumper in place.
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Re: Ice Tube Clock Transistor Related Display Issue

by adafruit_support_bill on Tue Dec 29, 2015 4:41 pm

If you contact support@adafruit.com with a link to this thread we can send a replacement Q3.

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Re: Ice Tube Clock Transistor Related Display Issue

by phild13 on Wed Jan 20, 2016 1:05 am

I know this is a bit of an old post but thought I would make a few comments that may help or may help someone in the future. Please don't take what I say wrong or as an attack I am trying to explain what I see may be wrong so that you may have a successful build.

* There is a Jumper connecting the two outside terminals of the 5 Volt power regulator IC3. These outer terminals on the regulator are power in and regulated power out. Since the jumper is shorting out the power regulator, this is effectively supplying 9vdc to all components on the board which is very bad. Some components such as the processor and the display driver can only tolerate about 5.5 volts and they therefore probably did not survive the application of that high of 9vdc to their vin pins.

* John (Jarchie) described how to jumper the leads of Q3 not IC3.
The FET Q3 acts as a switch to supply filament power to the display tube and to also supply power to the display driver IC2. The FET is easily damaged by static when handling before it is installed and as a result may not turn on completely and not supply enough voltage. There were also some Q3 FET's supplied in the kits that were out of spec. and also would not supply enough voltage,

* While the solder joints look pretty good on the bottom side of the board, not enough solder appears to have been applied to fill some of the pads completely through to the top side which has resulted in starving the top side of solder. This could also be from not quite enough heat being applied to properly flow the joint (pads). While the component pads are plated through holes, it is still a good practice to apply just enough solder and heat so the solder will wick to fill the pad on both sides of the board. Most two side boards have traces on both top and bottom and this ensures that if a plated through pad is defective in some way that both top and bottom sides of the pads and the component are all electrically connected.

* There are some solder joints on the tube board that look like they are also starved of enough solder and should be resoldered.

What I would do.
- all voltage measurements are from the ground reference which is the big silver tab of IC3.
- Some of the recommendations on component replacement below is based on applying excessive voltage to the components by accidentally jumping the leads on IC3.

- Carefully Remove IC1 and IC2 from their sockets and place on antistatic surface or back in their carriers/bags if you still have them.

- Remove the Jumper from IC3

- Resolder the components/wires on both boards that have pads that are shy of solder. If you have trouble getting solder to flow to the top side of the board, you can touch up the top side with the soldering iron and a bit of solder rather than risk excessively heating a pad or component.

- power the board with 9vdc from the power brick (wall wart) and check for 9vdc on the bottom pin of IC3 (closest to board edge) If you don't have that, then work back to find where it disappeared and fix that component.

- then check for 5 volts dc on the top pin of IC3 (pin farthest from the board edge when looking at the top of the board) to the big tab (ground reference) of IC3. If you do not have 5 volts, then replace IC3

- Install IC1 and power the board up. If you hear a beep then all is good and the processor may not be damaged, if no beep you will have to try to get get another IC1 programmed for the icetube clock from Adafruit. If they can't supply the programmed chip then you can get a blank chip from DigiKey and program it yourself (we can help).

- once you get the processor beep upon power up you can proceed with the rest. The rest below will not work until you get the processor working properly.

- Check voltage for the FET Q3. Turn board over upside down (bottom side up) check for voltage at the lead farthest from the board edge. Then check the lead closest to the board edge for about the same voltage. The voltage will usually be a bit less than 5 volts, but should be almost the same or the same on both pins of Q3.

- Now check for boost voltage on the striped end of D3 it should be at least 40 volts but not over 70.

- If you have boost voltage, then remove power and install the display chip IC2

- apply power again and check for the processor beep. If no beep, then check for 5 vdc on upper lead of IC3 and see if any fuse is excessively warm. If no voltage or fuse or IC2 is hot or very warm, then replace IC2.

- If you have a processor beep, then remove power and install the tube board and power on again. If you have no display or a partial display, replace IC2

Hope this helps some....

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Re: Ice Tube Clock Transistor Related Display Issue

by jarchie on Wed Jan 20, 2016 3:43 am

phild13 wrote:There is a Jumper connecting the two outside terminals of the 5 Volt power regulator IC3.

I read the first post a while back and totally missed this in the board photo. Nice catch, Phil!

phild13 wrote:Some components such as the processor and the display driver can only tolerate about 5.5 volts and they therefore probably did not survive the application of that high of 9vdc to their vin pins.

I've seen clock power shorted in a similar way and was surprised when nothing was blown. Perhaps I'm being optimistic, but I think there is some hope that crashkaboom's components are still functional.

(On the Adafruit board design the +9v trace for the boost circuit passes right under a sharp edge of the metal battery holder. By pushing down too hard on the battery holder, the metal will cut through the soldermask and make contact with the +9v trace. And voila! The whole clock is now powered by +9v, with a tiny bit of voltage drop through D1 and D4. I've only seen this happen once, but everything worked fine after fixing the short.)

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Re: Ice Tube Clock Transistor Related Display Issue

by phild13 on Wed Jan 20, 2016 11:57 am

Based on the description that crashkaboom provided, hopefully everything survived. I have done dumb things or made a circuit mistake with some of the alternate circuit boards some of us made and except for 1 board that I somehow damaged a processor in, the components survived.

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Re: Ice Tube Clock Transistor Related Display Issue

by crashkaboom on Fri Jan 22, 2016 11:56 am

I appreciate the notice and the advise. I'm a novice in electronic circuits and I tend to stick to the software side of these things. As I noted in my original post, I was simply following advice that given by jarchie in different, but related post. If I remember correctly, there was even a followup reply from bill from Adafruit Support mentioning that the jumper test was a great solution to the OP's troubleshooting. For what it's worth, my clock is running great since Adafruit supplied me with a replacement transistor. I also just want to thank all of you for being incredibly supportive in this forum.

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Re: Ice Tube Clock Transistor Related Display Issue

by jarchie on Fri Jan 22, 2016 1:43 pm

crashkaboom wrote:For what it's worth, my clock is running great since Adafruit supplied me with a replacement transistor.

That's the important thing! And congratulations on successfully fixing your clock!

crashkaboom wrote:As I noted in my original post, I was simply following advice that given by jarchie in different, but related post. If I remember correctly, there was even a followup reply from bill from Adafruit Support mentioning that the jumper test was a great solution to the OP's troubleshooting.

If you look carefully at your origional photos, you'll see that IC3 (the voltage regulator) is jumpered. My advice was to jumper Q3 (the transistor that Adafruit replaced). Jumpering Q3 is safe, but jumpering IC3 is not. Phil was just worried that confusing the two parts might have damaged your clock.

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Please be positive and constructive with your questions and comments.