ELOR problems

[rangebob]

I received my ELOR and have soldered it up. I connected it to the computer and didn't get the sync linght when I attached the 45 to the black port. From the directions it said that I had to connect DC power to it so I had a wall wort that said it had 12v ~300mA so I attached it. It had a white line on it which when tested showed +. I attached it to the J3 (going by memory here) and it was find but didn't get the sync light. I then attached the 45 and shortly after I had some smoke from the board so I quickly disconnected it. I checked over the board and all looks OK right now. The smoke was coming from the large cap (I think the 35 labeled piece).

Now the setup; the 45 is coming out of the comptuer via a USB - Serial connector with the RS485 from LOR. When I tested the wall wort it is throwing out 19v DC and 60v AC. I know that the DC is OK since it said between 6 & 24v. Could it because it is throwing out some AC have caused my smoke or is my 45 the problem. Also is there anything else that I need to look at on the board for damage.

[David_AVD]

Oh no - you let the magic smoke out!

[jstjohnz]

LOR sells powered RS485 adapters and non-powered RS485 adapters. If you have a powered adapter then you don't need the external power supply, but if you have a non-powered RS485 adapter then you do need the external supply. The jumper on the ELOR should be installed only if you are getting power from the LOR network.

The 60 volts of AC that you mention doesn't sound right at all. How exactly did you measure that? Was the 35 volt 10uf tantalum capacitor installed backwards by any chance?

I would suggest trying another power adapter. Unplug the LOR network and remove the LOR jumper. Attach the power adapter with + to the upper pin of J3 and - to the pin below that.

Before powering up, verify that the polarity of the tantalum capacitors is correct. I would suggest removing the cap that smoked. It should work without it.

If you smoked that cap, it could either be because it was installed backwards, or was subjected to too high of a voltage. If there is really 65 volts of AC coming out of that adapter, that's a big problem.

With power applied to the ELOR, you can check the on-board supply voltages. The left-hand pin of the 3.3V regulator should measure 5 volts to ground, the right-hand pin should measure 3.3 volts to ground.

[rangebob]

OK, I guess I did get the 35 in backwards. I got it removed and the LOR sync light is blinking. I connected it to the RS485 and it keeps blinking. I've checked over the entire board and have freshened up all of the joints with no changes.

When you say to check the polarity of the tantalum capacitors. I have the power disconnected I don't get anything across them. I presume I need to check for DC current accross the points.

I've checked all of the pins on the PICs and none of them are bent.

[jstjohnz]

You need to be sending LOR data in order for the sync light to go solid. Either the hardware utility running or the sequencer running. As far as checking capacitor polarity, meaning that the + mark on the cap lines up with the + mark on the PC board.

[rangebob]

I don't know what happened. I responded yesterday morning but it didn't upload completely I guess.

The + are in the correct orientation, I have attempted both having hardware Utility running, scanning for HW, running a sequence all with no luck.

Do you have any other suggestions?

[Dennis Cherry]

Your first post stated 12V ~300ma, this to me says your wall wort is a 12V AC 300ma transformer, not a 12V DC 300ma power supply.

Dose it make any difference to the ELOR?

[jstjohnz]

I would suspect that the RS485 transceiver IC for the LOR network is bad. You could try swapping the 2 RS485 chips to see if that helpse. If they both got zapped that won't help but if the problem is only with one that should make the sync les go solid on. If that doesn't work you can send it back to me and I'll take a look at it.