stevedave1138 Posted July 28, 2012 Share Posted July 28, 2012 My biggest nightmare just came true....I just attempted to test 2 Rainbow Floods and 1 Rainbow Spotlight on my new DC controller (CMB16D-QC)I ran the LOR Hardware utility. Once I attempted to turn on the lights, I noticed a burning smell, and the lights quickly went out. I disconnected from power, to find smoke coming up from the controllers circuit board. The heat was directly from the Q8 heat sink...I am of course devastated and am hoping I did not make a mistake in setup, but here's is what I have hooked up:1.Power Supply is a DC12V 15A power supply. I have verified voltage and all connections for polarity...ALL CHECK.2.2 Rainbow Floods which use channels 1 - 6 for RGB, and a spotlight using channels 7-9.Connected asRed = channel 1 NegBlack = channel 1 POSGreen = channel 2 NegBlue = channel 3 negAnd so on for the next 2 lights...All channels (for each light) sharing the same positive..I have had no problems testing lights before with this unit, but always just had one light hooked up at a time. I hook up three and this happens??Where oh where did I go wrong????? ive never even had the chance to use the poor thing..... Link to comment Share on other sites More sharing options...
Tim Fischer Posted July 28, 2012 Share Posted July 28, 2012 (edited) Wait, you're using heat sinks? Are you using proper isolation?The tabs on the mosfets (the part you burned out) are electrically live, and you can't just bolt it to a standard heat sink like the AC boards. From the manual:Metal Tab Transistor Consideration CMB16D-QC boards have transistors with metal tabs. Heat sinks are not required if the current draw per channel is 4 amps or less. The metal tab of the transistor is electrically hot and a TO-220 insulating kit (mica wafer and screw grommet) is required when mounting the transistors to metal heat sinks. Also, keep this fact in mind when using the board since it is possible to short out the metal tab transistors. (emphesis LOR's)Not sure that's your problem, but it's somewhere to start. The good news is that the MOSFETs are relatively cheap and easy to replace, so long as you know how to solder. Edited July 28, 2012 by Tim Fischer Link to comment Share on other sites More sharing options...
Tim Fischer Posted July 28, 2012 Share Posted July 28, 2012 I should add that if you're using a single Rainbow channel on each output, you don't need heat sinks at all. Link to comment Share on other sites More sharing options...
WilliamS Posted July 28, 2012 Share Posted July 28, 2012 Can you post a picture of the setup? This might help us figure it out real quick. Im with Tim with the heat sink question. Link to comment Share on other sites More sharing options...
stevedave1138 Posted July 28, 2012 Author Share Posted July 28, 2012 Ok I will clarify, I'm not using heatsinks..its the Q8 mosfet that is heating up..I beleive perhaps since I am spanning two banks of channels with one RGB light that perhaps the load is increased?Meaning the spot ligght uses channel 7 andf 8 of one bank, and channel 9 on the next banks, with each bank receiving 12v form the power supply..I have disconnected the light from the channels, and the CARD IS NOW RESPONSIVE AND FUNCTIONING!!!! But I believe that I have fried cvhannels 7, 8 and 9. Link to comment Share on other sites More sharing options...
stevedave1138 Posted July 28, 2012 Author Share Posted July 28, 2012 http://i154.photobucket.com/albums/s250/madhatter1138/2012-07-28125717.jpg Link to comment Share on other sites More sharing options...
Tim Fischer Posted July 28, 2012 Share Posted July 28, 2012 Spanning a bank is fine so long as you're using the same power supply (and maybe the same outputs of the power supply - not sure about that). I do it with my own setup. Link to comment Share on other sites More sharing options...
Surfing4Dough Posted July 28, 2012 Share Posted July 28, 2012 Spanning a bank is fine so long as you're using the same power supply (and maybe the same outputs of the power supply - not sure about that). I do it with my own setup.Do the same here too. Link to comment Share on other sites More sharing options...
Guest wbottomley Posted July 29, 2012 Share Posted July 29, 2012 Ok I will clarify, I'm not using heatsinks..its the Q8 mosfet that is heating up..I beleive perhaps since I am spanning two banks of channels with one RGB light that perhaps the load is increased?Meaning the spot ligght uses channel 7 andf 8 of one bank, and channel 9 on the next banks, with each bank receiving 12v form the power supply..I have disconnected the light from the channels, and the CARD IS NOW RESPONSIVE AND FUNCTIONING!!!! But I believe that I have fried cvhannels 7, 8 and 9.I would submit a support ticket. Link to comment Share on other sites More sharing options...
CLD Kevin Posted July 29, 2012 Share Posted July 29, 2012 I ran 5 double RB off 1 DC board....basically 10 single RB floods with plenty of power left to add more. I doubt you over powered that channel. Sounds like something crossed or touched....maybe the RB itself? Kevin Link to comment Share on other sites More sharing options...
stevedave1138 Posted August 7, 2012 Author Share Posted August 7, 2012 The problem was that I was using both tab outs on the DC power supply , one set to one bank, the other to the other bank. Apparently this is bad, as it cooked channel 8. I ran from the one set of tab outs to each side, and all is fine.Except channel 8 is still cooked. Oh well. Link to comment Share on other sites More sharing options...
stevedave1138 Posted August 7, 2012 Author Share Posted August 7, 2012 I have been asked about the enlosure i used.It is made by FAAC, and is for automatic gate systems, it comes when you order the gate kit. I use them for work, and they fit a large D/C PSand the board nicely. Link to comment Share on other sites More sharing options...
flogger7 Posted August 8, 2012 Share Posted August 8, 2012 The problem was that I was using both tab outs on the DC power supply , one set to one bank, the other to the other bank. Apparently this is bad, as it cooked channel 8. I ran from the one set of tab outs to each side, and all is fine.Except channel 8 is still cooked. Oh well.Why is that bad? Link to comment Share on other sites More sharing options...
Max-Paul Posted August 8, 2012 Share Posted August 8, 2012 some power supplies have two or more what they call rails. In effect it is like two power supplies in one box. And the neutrals or commons might not be joined on a common buss. I believe that on the DC board the common is not a common buss. So, the one on #8 was not able to return to it's common, cause the common was on the high numbered bank. Link to comment Share on other sites More sharing options...
WayneKremer Posted August 8, 2012 Share Posted August 8, 2012 Well that's scary. From what I understand, this is a common practice. How is anyone to know? Link to comment Share on other sites More sharing options...
Max-Paul Posted August 8, 2012 Share Posted August 8, 2012 Well that's scary. From what I understand, this is a common practice. How is anyone to know?Pay attention to what you are ordering. Things to watch for is a power supply that says something like "V1, V2" V1 and V2 indicates you have a voltage 1 and voltage 2 or two power rails. I cant really see the ops power supply screw terminals and the label for what each screw is. OP can you verify what I am saying. Link to comment Share on other sites More sharing options...
Steven Posted August 9, 2012 Share Posted August 9, 2012 I believe that on the DC board the common is not a common buss.Page 11 of the CMB-16D-QC manual says:"The ground between the two channel banks is common."I have verified this by examining the board.It seems unlikely, but if the dual power supply uses different grounds that can't be connected together, then this would be a problem. That doesn't seem likely, however, and I can't see why that would affect a single channel, so my guess is that channel 8 happened to have a bad transistor. Link to comment Share on other sites More sharing options...
Max-Paul Posted August 9, 2012 Share Posted August 9, 2012 Thanks Steven,I am corrected. The Common busses on the DC cards are common to both sides. Link to comment Share on other sites More sharing options...
Max-Paul Posted August 9, 2012 Share Posted August 9, 2012 Reflection bases on what Steven has said about the common busses being tied together on the DC card. With that being the case. Then even if you do have a dual rail power supply. Once those two common or negative wires (terminals) are connected to the DC controller card. They now are common to each other. Now going to go along and say that it must have been a bad mosfet. Link to comment Share on other sites More sharing options...
stevedave1138 Posted August 11, 2012 Author Share Posted August 11, 2012 Interesting. The PS does indeed have a V1 and V2, and I was using both,which I thought was the issue, and I still believe it was somehow. When hooked up this way the number 8 mosfet heats up very quickly. When hooked up with two sets of pigtails from V1, it does not. Although the damage was done to this channel. Link to comment Share on other sites More sharing options...
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