CMB24d - Red Channel Funkiness

[mpageler]

Have some funkiness going on with a cmb24d. Just curious if anyone has seen this type of action.

Have an 8 section rgb light bar and have 2 sections that aren't following the sequence's color effect correctly in very specific situations.

During a fade up/fadedown red chase through the 8 sections that have blue backgrounds,  2 sections change to magenta (red/blue 100

on blend) after the red fade down  inseast of changing to blue. Basically, appears the 2 red

channels turn back on after the chase fade down completes.  

Have done other testing and no issues with changing from complete on red, blue, green or

white colors. Did notice that with a yellow fade down to 0 at the end of a sequence, these 2 same sections have a non-yellow fade color.  Hard to tell the color but guessing it

might be the red channel staying on longer as the green channel

fades completely off

The controller did receive a "jolt" when it's wire hardness dropped down and the garage down caught it and gave the controller a yank.  I did a lot of color changes to sequences during the display season and don't know if this incident, coinsides with the issue on the 2 sections. A couple times, one of these 2 sections would not come on.  Did a lights on/off in hardware setup and got it working

again.  

I have 3 cmb24d in the display and need  to get another one for backup. Would proabley switch out boards and then decide if needed whether to send the funky cmb24 in for LOR to take a look see. Or just keep it and know if have several quirky channels. Other than myself, don't know that anyone else would even notice the problem.

So just fluky action orboard probalby needs a repair?  Other thoughts...thanks

Edited April 5, 2016 by mpageler

[k6ccc]

I would be very surprised that a controller would fail in the way you describe.  My first thought is a sequencing issue, followed by a strip issue.  I'll address both.  If you have a second controller, swap to it and see if the problem exist in the second controller.  If the problem is the same, it's the strips or sequence.

First guess is you have something of a leftover in the sequence.  It's not that hard to end up with a sequence that has something like 2% of a color turned on and you really can't see it on the SE screen, but with LEDs, 2% is quite visible.  Float the cursor over the cells in question and see what it shows for the levels.

As for the strips, were they strips bought in the same batch?  Different batches of strips can have subtle color differences that are not all that visible unless they are close together - and then they stand out like a sore thumb. Try moving the strips around and see if the problem follows the channels on the controller or the strip.

 

[mpageler]

Yep..not your normal problem that people reports.

I did concentrate on the sequence when it was happening.  Ran the verification process and did find some channel conflict issue that affect other places in the display but nothing for these light bar elements. 

 

They use a number of rectangle rgb modules in each of the 8 light bar segements.  All bought in one order.

 

I will take a further look at the sequence, If I can rembmer which one it was...crap.  While testing, I think I created a new 10 second chase sequence and had the same issue I believe but just don't remember anymore. 

 

Have the display elements stored away but was going to see if I could get to the light bars and pull one out w/o plulling everthing down form the garage overhead storage racks.

Didn't think about trying another controller..good idea. At least the controller are easily accessible yet. 

 

 

 

[Grinch]

I had a something weird like you are saying last year.   Tested each RGB separately and they would be correct, hook them all up then in few minutes they were weird.  First I Found my power supply failing, replaced that then once that was working, a couple nights later it was acting up again and  I found two bad triacs.

[George Simmons]

I also had a red channel triac go bad last season on a new CMB24D.  Hmmm...  Starting to sound more and more like a sinister coverup is going on somewhere ...

One more reason I like having odd numbers of display elements - in this case a 7 channel fan - is that I was quickly, easily and (somewhat) conveniently able to cover for the bad channel.

[k6ccc]

11 hours ago, George Simmons said:

I also had a red channel triac go bad last season on a new CMB24D.  Hmmm... 

 

Hey George, on the DC controllers, it's a MOSFET, not a TRIAC (that's why they call it the CMB and not CTB).  With DC power, once a triac was turned on, it would never turn off (triacs depend on the zero voltage crossing of AC power to turn off).  Not trying to be picky, just to learn you something.  Damn, I used that grammar and I haven't watch the Beverly Hillbillies in years!

 

[George Simmons]

22 minutes ago, k6ccc said:

Hey George, on the DC controllers, it's a MOSFET, not a TRIAC (that's why they call it the CMB and not CTB).  With DC power, once a triac was turned on, it would never turn off (triacs depend on the zero voltage crossing of AC power to turn off).  Not trying to be picky, just to learn you something.  Damn, I used that grammar and I haven't watch the Beverly Hillbillies in years!

Thanks.  It's a good thing (a VERY good thing actually) that I'm too dumb to even think about repairing my own controllers.

Did you prefer the original or the replacement Ellie Mae?

[mpageler]

I guess several quirky red channels is better than non-working channels...how that for glass 1/2 full?

 

Definately learning the benifits of having unused channels in controllers for tuture channels issues.

 

Curious how easy it is to replace mosfets in cmpb24d.  Saye a video on replaceing triacs in an AC controller...lots of controller disassemble, just to get at the triac, which wouldn't be the case with a cmb24 board.

[Dennis Laff]

first

[PURSUIT OF EXCELLENCE]

Not to be nit picky gentlemen but Triacs are for AC control such as on the CTB boards and are definitely not for RGB control.  The CMB24D uses MOSFETs (transistors).

Had a similar problem and found a bad solder joint on the mosfet for that channel. Brand new board by the way.

I also agree that when a small left over is in the program, such as a 2% red I was using in my gold star color, it gets funky. My situation was caused by the sequence editor which sometimes fills a whole channel in when you try to color fade a single block or two.  Anyone else get pissed off when that happens?  It set the whole channel to 2% red and you can't see it in the sequence editor unless your superman!  Most of that got overwritten by other programming but there were instances when it wasn't. Good luck.

[Mr. P]

6 hours ago, mpageler said:

Curious how easy it is to replace mosfets in cmpb24d.  Saye a video on replaceing triacs in an AC controller...lots of controller disassemble, just to get at the triac, which wouldn't be the case with a cmb24 board.

Very easy to replace yourself if you have basic soldering skills. It will only take 2-3 minutes since the board is so easy to take apart.

You can get the mosfets here:

http://www.mouser.com/ProductDetail/NXP-Semiconductors/PSMN022-30PL127/?qs=sGAEpiMZZMshyDBzk1%2FWiy8mkjihaa%252bLT7ikOfKaAiM%3D

[LOR Staff]

If you have the proper tools and experience, replacing a Triac or Mosfet is an easy thing to do.

However, if you do not have the skills or the correct tools, you can also very easily damage the board to the point that it can't be repaired even by us.  Mosfets and Triacs have big legs which require a large quantity of heat to melt and remove.  Overheating a pad (the spot on the board where the device itself connects) is the fastest and easiest way to break one off.  Once a pad is popped, there is no fixing it.

if you have the experience, we can send you the part.  Simply open a help desk ticket.

[indi]

DevMike, I have a soldering station with a heat gun attachment that is said should be used for elements with a lot of soldering points. Would it be safe to use to desolder these components. sThank

[LOR Staff]

Beware.  You can really do some damage with a hot-air rework (heat) gun

What you really need is an auto-magic solder sucker vacuum.  I've recommended this station before, and it is the one I use:

http://amzn.to/1Nc4vhs
(Edit:  Wow, and I think the price has dropped by $100.  I think I paid $399 for mine)

The 'gun looking thing' is my desoldering weapon of choice when replacing triacs/etc.  Put it on the pad, when the solder melts pull the trigger.  Clean hole.

Using the hot air tool (that's the thing on the left side of the main picture) is probably not a starter.  First, you would need to get a spreader that is the exact size of the 3 through-holes.  I've never seen one of those.  But even with the proper size spreader, it won't clean out the holes very well. 

[indi]

Thanks for the info. My hot air has a number of of spreaders some are pretty small. But I will follow your advice and get a desolder gun. Thanks again.