Monochron Kit left overs
Moderators: adafruit_support_bill, adafruit

Monochron Kit left overs

by chiragpatnaik on Mon Aug 20, 2012 9:19 am

I finally got hold of the Monochron Kit I ordered a few weeks back. I assembled it and it works fine. One observation.
Wherever there is a lighted drawing, there seems to be a trace that runs vertically. For .e.g the two paddles. Along with the paddles there is a faint line that runs through the entire vertical. Similarly for the time etc.

Also, I was left over with the following.

16 header pins long/short(I broke 20 out of these from the long strip. should have been 20?). it's a spare so I guess it is immaterial.
6 header pins long/long (I assume this is for the FTDI port)
2x3 header pins long/short (I assume for ISP?)
100uF Capacitor (spare)
100 Ohm resistor (spare)
10K Ohm resistor (hope I didn't miss anything). The only 10K I used was the pot.

Thanks for looking.

Chirag
Last edited by chiragpatnaik on Sun Sep 16, 2012 7:18 am, edited 1 time in total.
chiragpatnaik
 
Posts: 18
Joined: Wed Jul 11, 2012 10:25 pm

Re: Monochron Kit left overs

by adafruit_support_rick on Mon Aug 20, 2012 10:01 am

chiragpatnaik wrote:100 Ohm resistor (spare)

You received 2 100Ohm resistors? You did put one into R2, right?
chiragpatnaik wrote:100uF Capacitor (spare)

You mean 100nF? You got 4 of these? You did put the other three in C1, C3, C5?
chiragpatnaik wrote:10K Ohm resistor (hope I didn't miss anything).

Weird - that's not even on the parts list. You should have got 9 resistors total, plus the pot.

Persistent vertical lines could be caused by a poor connection. If you post clear pictures of the front and back sides of you PCB, we'll have a look.

adafruit_support_rick
 
Posts: 12878
Joined: Tue Mar 15, 2011 11:42 am
Location: Buffalo, NY

Re: Monochron Kit left overs

by chiragpatnaik on Mon Aug 20, 2012 10:14 am

driverblock wrote:
chiragpatnaik wrote:100 Ohm resistor (spare)

You received 2 100Ohm resistors? You did put one into R2, right?
chiragpatnaik wrote:100uF Capacitor (spare)

You mean 100nF? You got 4 of these? You did put the other three in C1, C3, C5?
chiragpatnaik wrote:10K Ohm resistor (hope I didn't miss anything).

Weird - that's not even on the parts list. You should have got 9 resistors total, plus the pot.

Persistent vertical lines could be caused by a poor connection. If you post clear pictures of the front and back sides of you PCB, we'll have a look.



I put the 100 Ohm into R2' pretty sure of it. There was one extra.
I put 3 caps in C1,C3,C5
There was an extra 100uF 6.3V cap
I got 11 resistors plus the pot.

Didn't realise it was an issue and struggled :) and cased up the clock and then turned it on for a critical examination. Though I checked almost every solder joint, before I moved into the next step including connectivity of the IC sockets. Will open it up next weekend to take pics and post here.
chiragpatnaik
 
Posts: 18
Joined: Wed Jul 11, 2012 10:25 pm

Re: Monochron Kit left overs

by chiragpatnaik on Sun Sep 09, 2012 11:35 am

Reopening this thread with pics as requested.

Here is what it looks like before disassembly.
image005.jpg
Trace lines are clearly visible here.
image005.jpg (214.51 KiB) Viewed 1808 times


Another shot
image006.jpg
Another shot
image006.jpg (252.89 KiB) Viewed 1808 times


Yet another
image007.jpg
Yet another
image007.jpg (235.63 KiB) Viewed 1808 times


Pics of the Front and rear of PCB in the next post
chiragpatnaik
 
Posts: 18
Joined: Wed Jul 11, 2012 10:25 pm

Re: Monochron Kit left overs

by chiragpatnaik on Sun Sep 09, 2012 11:39 am

Rear of the PCB
image008.jpg
Rear of the soldered PCB
image008.jpg (489.95 KiB) Viewed 1808 times


Front of the PCB
image010.jpg
Front of the PCB
image010.jpg (458.16 KiB) Viewed 1808 times


Just in case... Here is a shot of the headers soldered on the LCD Board

image011.jpg
Headers soldered onto the LCD board.
image011.jpg (372.19 KiB) Viewed 1808 times


Any help is much appreciated.
chiragpatnaik
 
Posts: 18
Joined: Wed Jul 11, 2012 10:25 pm

Re: Monochron Kit left overs

by chiragpatnaik on Sun Sep 09, 2012 11:48 am

I have checked the continuity on every joint (really). Let me know if I should check something specifically again.

This was my first big kit. Please do comment on my soldering skills. I have to assemble the Ice Tube clock kit the coming weekend. :D
chiragpatnaik
 
Posts: 18
Joined: Wed Jul 11, 2012 10:25 pm

Re: Monochron Kit left overs

by adafruit_support_rick on Sun Sep 09, 2012 12:39 pm

Does adjusting the trim pot have any effect on the problem?

Overall, the soldering is not too bad. There are a few spots where the solder is blobbed up a bit - that may indicate that you didn't heat the pad well enough, so the solder didn't flow onto the pad completely. This usually leads to weak or intermittent connections.

Some of the LCD pins look like the could use to be touched up. It's hard to tell, but they may be cold or disturbed joints. Or maybe they could just use a little more solder. Reheat them to get good wetting and flow.

There are a lot of leads that you clipped pretty long. Generally, you want to clip them down to the top of the solder.

Adafruit just put up a really nice guide to soldering. You probably want to review it before touching up the Monochron and starting on the Ice Tube.

I annotated your picture to point out a few suspicious-looking solder joints:

monochron.jpg
monochron.jpg (625.5 KiB) Viewed 1804 times

adafruit_support_rick
 
Posts: 12878
Joined: Tue Mar 15, 2011 11:42 am
Location: Buffalo, NY

Re: Monochron Kit left overs

by chiragpatnaik on Sun Sep 09, 2012 12:44 pm

I tried playing around with the trimpot. Don't think it was having an effect. Will retouch the solder as indicated. Be back next weekend. :)
chiragpatnaik
 
Posts: 18
Joined: Wed Jul 11, 2012 10:25 pm

Re: Monochron Kit left overs

by chiragpatnaik on Sun Sep 09, 2012 12:56 pm

Could the shorting of casing of the push switches have an effect like this? I think I may have shorted two of them (the posts not the electrical points). See the front of the PCB. The switches closest to the barrel jack adapter.
chiragpatnaik
 
Posts: 18
Joined: Wed Jul 11, 2012 10:25 pm

Re: Monochron Kit left overs

by adafruit_support_rick on Sun Sep 09, 2012 1:32 pm

The switch cases are all attached to GND, so shorting them won't be a problem.

adafruit_support_rick
 
Posts: 12878
Joined: Tue Mar 15, 2011 11:42 am
Location: Buffalo, NY

Re: Monochron Kit left overs

by adafruit_support_bill on Sun Sep 09, 2012 4:28 pm

You have a stray blob of solder between the capacitor leads as shown below:
Monochron.png
Monochron.png (493.5 KiB) Viewed 1779 times


It's hard to tell from the top-view, but some of your soldering on the header for the LCD show signs of unsufficient wetting of the pad. Chek the last page of the soldering tutorial referenced by Driverblock for some tips on fixing these.
User avatar
adafruit_support_bill
 
Posts: 30829
Joined: Sat Feb 07, 2009 10:11 am

Re: Monochron Kit left overs

by chiragpatnaik on Fri Sep 14, 2012 11:35 am

adafruit_support wrote:You have a stray blob of solder between the capacitor leads as shown below:



It's hard to tell from the top-view, but some of your soldering on the header for the LCD show signs of unsufficient wetting of the pad. Chek the last page of the soldering tutorial referenced by Driverblock for some tips on fixing these.


It wasn't a stray blob of solder. It was some flux. I checked the continuity. (In any case, the clock was functional).

Anyway went through all of what you mentioned. Checked continuity for the suspicious joints again. Looks the same as before.

Just pleased I didn't break anything. So I put it back in the case. I guess I would have to live with it.
chiragpatnaik
 
Posts: 18
Joined: Wed Jul 11, 2012 10:25 pm

Re: Monochron Kit left overs

by adafruit_support_rick on Fri Sep 14, 2012 12:46 pm

Some LCDs are more susceptible to this appearance than others. If you'd like, we can try replacing it with another. Please contact support@adafruit.com with a link to this thread.

adafruit_support_rick
 
Posts: 12878
Joined: Tue Mar 15, 2011 11:42 am
Location: Buffalo, NY