USB 485 up in smoke

[yldjack]

been having problems since I tried to do Halloween show  it ran for 2 days np then

no communication to the controllers, I checked all cable connections everything was good so I ordered a new 485  plugged it in and worked for 2 days went to help desk they had no answers so they sent it to engineering they had nothing either so they sent me a new one 

I also ordered a new highspeed 485

now Christmas is here started my set up a little every night running each night until tonight same thing com port is open cant run so I switch out to the highspeed 485  just to 1 controller  PUFF magic white smoke.

I have been running LOR for 9 years now I us a XP laptop that is stand alone no internet  only used to run my shows

I have gone thru 4 USB 485 where is my problem is my laptop doing this

[TheDucks]

First question (since you have years of LOR under your belt): What changed or was added that was not there previous years.

(and what controllers are on the failing network)

Do check the USB ports have only 5V +/- .25V   (I can't imagine just the ports with issues as 5V is used thru out the mainboard )

[yldjack]

Halloween I ran 1 16ch and 2 -  cmb24 for my dumb leds

I had to change ends on cat5 

I'm an electrician and used test equipment to test cables  after adding new ends nothing other than that new

from Christmas  the 16 ch  I used for Halloween is not hooked up yet I have 2 16 ch  and 4 cmb24 now was ready  to add the other 16 ch 

 

al controllers  laptop 3" away from first controller

Edited December 1, 2019 by yldjack

[TheDucks]

1 hour ago, yldjack said:

Halloween I ran 1 16ch and 2 -  cmb24 for my dumb leds

I had to change ends on cat5 

I'm an electrician and used test equipment to test cables  after adding new ends nothing other than that new

from Christmas  the 16 ch  I used for Halloween is not hooked up yet I have 2 16 ch  and 4 cmb24 now was ready  to add the other 16 ch 

 

al controllers  laptop 3" away from first controller

You have to have a controller out there that has something seriously wrong (leakage getting onto 4+5)

LOR uses the blu-whi pair for RS485 signal There is another pair with 9V to power ELL or similar accessories.

If this was a Desktop PC, I might guess Ground loop from a missing Green ground. Someone has not connected a Ethernet switch to you network chain? That would do it (and probably hurt some controllers.)

568 A or B normally leaves the blue pair free ( I believe it was intended to share with a POTS line), But POE equipment has made use of all 4 pair, so I have no clue to what happens. POE can supply up to 15W at 48V

[yldjack]

i'm going to make a patch cord to check on leaking voltage

I disassembled a 485 they only use 3 wires to the cat5 jack

no ethernet has been hooked to a controller

will any usb to 485 work ? jw

[yldjack]

I'm running 2 different types of controllers I have

3) CMB-24-d-6v and I have 3) CTB16pcg3

I have taken some voltage readings through the CAT5 ( T3 is green/white, T4 is blue, T5 is blue/white & T6 is green ) no other pair or wire showed any voltage

CMB-24 all boards showed same results

T3-T6 = 9v T3+           T3-T4=6v T3+      T3-T5= 6v T3+     T4-T5= 0v         T4-T6= 0v                        T5-T6= 0v

CTB 16 all boards showed same results

T3-T6= 9v T3+            T3-T4= 5v T3+      T3-T5= 7v T3+       T4-T5=2v T4+     T4-T6+ 2v T4+                T5-T6=0v

I'm figuring snice they all read the same this must be normal

I have ordered a min dir. don't want to plug it in and fry it

 

Edited December 4, 2019 by yldjack

[TheDucks]

Those sound normal.

That leaves: there is a Voltage difference FROM your PC to controller. The current path is NOT the NORMAL(those you measured)

VERY DANGEROUS , do not attempt if you do not have the needed skills

  Do You have a "Ground buster" (3 prong to 2 prong adapter with the green tab/ground wire removed?

One at a time, all Network cable removed.

Isolate the ground to each controller (CTB 16 will need 2 busters). Measure AC volts (start at line vale if not auto-ranged) Measure to a Known good ground from the Green  wire terminal  in the controllers, There should be no voltage (low volts scale)

I keep thinking there is a mis-wired POWER circuit, causing voltage to use the network cable (thus the dongle), as a path

Edited December 4, 2019 by TheDucks

[yldjack]

35 year electrician 

good call looks like my 12vdc power supply has a leak of 40v 😲  this is inside the house and not on a GFI  but aren't the 12v boards isolated from the line voltage

been thinking maybe 2 different problems I have had (4) 485 go bad only (1) smoked

gotta get the show up and running if I don't use the 2 cbm-24 inside  think the min-dir will work

 

[TheDucks]

17 minutes ago, yldjack said:

35 year electrician 

good call looks like my 12vdc power supply has a leak of 40v 😲  this is inside the house and not on a GFI  but aren't the 12v boards isolated from the line voltage

been thinking maybe 2 different problems I have had (4) 485 go bad only (1) smoked

gotta get the show up and running if I don't use the 2 cbm-24 inside  think the min-dir will work

 

50+ Years as a Senior Electronics Tech.  anything from 5VDc to 480V 3phase :;) I've had 10A contactors blow up in my face (the Breaker I toggled was in fron (saved my face), My ear rang for days.

There is some de-noise coupling components between Earth (green) and the DC-. Who knows what some of these $30 PSU's did. You might have had a double failure.

[jfuller8400]

I had something similar to this happen to me with a CMB24D a couple of years ago.  Smoked two black USB adapters before I finally found it.  Turned out one of the mounting screws I used for the PS extended a bit to far into it and touched something it shouldn't have.  I have no idea how or what it contacted or why it caused the weird voltage on the control lines (or even how it managed to create a pathway) but once I removed and replaced the screws, everything went back to normal.