USB485B gets hot to un-solder diodes - Controller software to blame?

[Douggg]

I'm going to make this as concise as possible.  I have 2 USB485Bs, four 16 channel AC controllers and one 16 channel DC controller.

 

It appears I'm having an issue with one of the AC controllers.  (The one that happened to be a spare.)

 

Last Christmas I decided to add it to my display.  When I did my LOR controller could not communicate with any of the controllers.  Not thinking it was a controller issues I did a lot of troubleshooting testing and replacing cables, changing controller IDs, swapping USB485Bs etc.  I found sometimes it would work, but then almost immediately it would fail.  Eventually the computer could not see any controllers.  I eventually removed the problem controller and found the USB485B wan't working.  Replacing with the spare and everything began working.

 

In looking at the USB485B box I found the two of the diodes became so hot they un-soldered themselves.

 

I'm going to save a lot of the troubleshooting details but I eventually created a new 485 network consisting of the working USB485B and the spare controller.

 

What I found was most of the time controller was reporting strange unit ID numbers or the software would report an error in the unit ID.

 

Several times I could smell components (which turned out to be diodes) getting hot enough they would un-solder themselves.

 

I've been able to rule-out the cables, the computer, unit IDs and after re-solder the diodes (several times) in both USB485Bs and using them in production form many days the only thing left as being the problem is the AC controller.  I'm finding sometime the LOR computer will find the controller and everything will appears to work fine.  Other times the controller will report an incorrect ID or the unit ID will have a error and sometimes I can smell that smell of electrical components overheating.

 

Any idea what's wrong with the controller?  (Seems like a short to me?)  And how I can fix it?

 

As I said this controller is new, it was a spare, never put into production.  I looked and don't see any lose wires or anything that might physically be causing a short.  I might be wrong but it seems like its' software that's causing the short.

 

Need your assistance.

Thanks.

 

Note to the folks are LOR, I just submitted a "Help ticket".

 

[jlowe]

Sounds like a short. Perhaps full AC voltage is crossing over somewhere? With LOR's support, I would just let them check it out/fix.

[Tim Fischer]

Could be a short in the 5V power (which is carried on 2 of the 4 wires used on the LOR network) shorting out somehow.  I doubt it's AC or you'd have more than an unsoldered diode.

[Douggg]

Can the short be caused be faulty software in the LOR controller? 

I've spent hours looking at this and can't find a physical short.

[LOR Staff]

No, the software on the controller can not do that.

 

I answered your ticket and started an RMA.  Please check it and we'll get you going.

[Tim Fischer]

I just realized you have the "booster" adapter... If something is shorting out the power pins (e.g. faulty cat5, faulty jack on the controller) I'm guessing that would cause the symptoms you have.

check the pins in the Cat5 jacks to make sure they aren't crossing over...

[Max-Paul]

Tim,

Just for the sake of discussion. I thought that the ELLs used 9VDC. Thus the voltage present on the RJ-45 socket is 9VDC.. So, I am mistaken what voltage the ELL uses?

 

"I beseech you, in the bowels of Christ. May it be possible that you are mistaken?" Oliver Cromwell.

[Tim Fischer]

Tim,

Just for the sake of discussion. I thought that the ELLs used 9VDC. Thus the voltage present on the RJ-45 socket is 9VDC.. So, I am mistaken what voltage the ELL uses?

 

"I beseech you, in the bowels of Christ. May it be possible that you are mistaken?" Oliver Cromwell.

Oops, I meant 9V.  I have 5V and 12V on the brain from RGB stuff lol. 

Spirit of my post is still correct though - I bet there's a short somewhere that's causing the booster to overheat.

[Max-Paul]

Yes, I agree the spirit of your post is spot on.