More (or similar) 836x overheat issues

[Mach7]

Hello All,

Ok....here is my continuing problem with which I thought I solved months ago.

My setup is using the 836x joystick board for flight controls, throttles, engine start, tiller steering, lift spoilers, and numerous switch selections.

Some time ago, I had an issue with my 836x board overheating (occasionally) to the point where is burnt itself out. (It actually got so hot it fried).

I received much help on this forum, and thought that possibly my Open Cockpit USB dc servo motor boards were finding an additional ground through the 836x thereby causing it to overload and heat up.

Since this time, I have eliminated the OC boards in replacement for Leo Bodnars CanBus arrangement for all 16 of my mechanical engine gauges. )I still use one OC board for flap indication only).

So here is my problem...with my brand new 836x board, everything worked perfectly for months until yesterday when it started to overheat again

This time, however, when the simulator is powered up, I can tell something is array when the number 4 engine begins to start all by itself with no selected inputs. The board begins to heat up, but I am able to remove the USB input eliminating it from its power source and allowing it to cool down....when I push the connector back in...everything is fine and I can run the sim for hours with no problems.

This only happens once in a while.....

The 836x board is connected to a hub which also has outputs for the rudder, nav's 1 and 2, and the MCP. (see pic).

I have checked all the connections for shorts, all of the start switches I am using to input to the board are aircraft specific, and they seem sound.

any thoughts?

[Mach7]

I think I might have found a solution.....

It seems that the 836x board does not like to be connected to a hub that also has a number of other USB outputs.

By connecting the board directly to the computer, there seems to be no problems so far....

-Jim

[blueskydriver]

Hey Jim,

I am curious about your electrical connections and how everything is plugged in? Is the USB Hub power plugged into a power strip along with other items, also where is your PC plugged into? My thinking is you have another powered device on the same outlet run somewhere else that gets turned on for some reason, like a bathroom light, hair dryer or anything really.

Thus, you are running items all on the same circuit (are you on 110v or 220v?) and at some point you're reaching the circuits amp threshold, but not tripping the circuit breaker. And, remember a 15amp only provides a usable amp of 12 or thereabouts. So, in other words, I think you board is getting overheated via the power circuit heating up to the threshold for whatever reason.

I can attest to this happening over the years and provide pics of overheat damage to power strips that get brown stained from heat, but still work, only ready to start a fire (I removed them already). Additonally, I've fried boards this way along with computer power supplies, so I suggest you check your circuit loads. If this is the problem, you should add a few extra circuits...

By the way, what if you have plenty of circuits, but the same thing still happens? Check the circuit breakers contacts on all of those being used. I once had a circuit breaker that caused my septic tank pumps to stop working, but the circuit breaker did not trip off. It looked perfectly fine and if I turned it off and back on the pumps worked fine for awhile, until a change in amperage occurred, it would shutoff, yet the switch was still on. I replaced the breaker with a new one and the problem never happened again.

This might not be your problem, but if I were you I'd checked all my power outlets and circuit usage.

John

[Mach7]

Hello John

I have contacted leo Bodnar and he seems to thing there must be a short on one of my analoge devices as the 836x board has no current limiter to the chip therefore it would contjnue to heat until it blows.

I will have to go over them one at a time again I suppose.

the usb hubs in question run off two separate power strips.

Jim

[Mach7]

@Blueskydriver

Hello John...i disconnected everything and went through all the pots, rotary and sliding and found no issues. I then checked all the switch connections and found one rocker switch to be suspect.

It is connected to the 836x board and controls the on/off function of the avionics (avionics master switch 1).

These swtiches are OEM 2tp1-3 types and have many years of service...however they do wear out.

This particular switch when tested was giving me a momentary on and off function when selected to "ON".

I have an ohm meter that I can set up to give a continuous high pitched 'beep' when the connection is closed...when I select this switch ON, the meter sort of growls a bit and you can faintly hear a tone until you wiggle the switch around its axis and then it will make the contact for a continuous beep.

If you brush by the switch or even gently touch it...it will lose the contact and be somewhere between open and closed, causing the ohm meter to go nuts again.

Could this create enough havoc on my 836x board?

I am thinking that if this switch is sitting at a semi shorted out position, it might cause the board to draw current and overheat.

what do you think?

-Jim

[KyleH]

.....

I am thinking that if this switch is sitting at a semi shorted out position, it might cause the board to draw current and overheat.

what do you think?

-Jim

Hi Jim,

Not really. The switch when closed causes current to flow through a short and a pure short would theoretically allow infinite current (at least up to what the power supply can handle).
I don't have a schematic for the board to look at but it would have been designed to limit the current through any switch connected to it.

The switch being in some intermediate state could be confusing the hell out of the microcontroller causing all your odd behaviors though. It would be a good idea to change it and see if it sorts out your problems.

[Mach7]

Thanks for the information Kyle.

I was kinda hoping that was the cause....oh well...back to the drawing board.

Leo did say that the board has no current limiting capability. However the switch may be the cause of some erratic behaviour, but like you said...probably not an overload/heat of the board.

[Mach7]

I also checked out all the on/off switch connections to the board and they are all sound.

I checked all the pots, and here are the values I came up with:

Nws rotary pot - Hitec brand - left   = 0.400 kohms   center = 2.3 kohms   right = 4.3 kohms

Lift Spoiler - sliding pot - ALPS RS601150k - retract  = 44.1 Kohms  extend = 19.9 Kohms

Thrust lever (one) - sliding pot - ALPS RS601150k - idle  = 48.1 Kohms full throttle = 12.1 Kohms

Flaps - sliding pot - ALPS RS601150k- flap 0 = 36.9 Ohms  flaps 18 = 9.80 Kohms flaps 24 = 23.2 Kohms flaps 30 = 37.4 Kohms and flaps 33 = 44.5 Kohms

Aileron rotary pot - taken from stripped down microsoft joystick - left = .459 Kohms center = 7.00 Kohms right = 10.0 kohms

Elevator rotary pot - taken from stripped down microsoft joystick  full back = 7.00 kohms center = 3.1 kohms full forward = 1.87 kohm

[mickc]

Silly question, but have you checked the wiring from the board to the pots?

I had a similar issue on a DU brightness pot, the pot tested fine, but i'd somehow pinched a wire under a screwhead, shorting it to ground.

[Mach7]

Nope...not a silly question at all...one of the first things I checked.

[Mach7]

I know it was pointed out that a bad switch contact would not create my aforementioned problem....I just hooked a multi meter onto the bad switch and when selected it ON.

I am getting an ohms reading of between a zero load and close to 200 ohms, (as the switch contact is just making the connection).

I have checked an exact switch type that is servicable and I get a .6 ohm resistance when the switch is closed.

Back to my original thinking...why could this high resistance on the switch not be creating my problem?

-Jim

[Bob Reed]

I know it was pointed out that a bad switch contact would not create my aforementioned problem....I just hooked a multi meter onto the bad switch and when selected it ON.

I am getting an ohms reading of between a zero load and close to 200 ohms, (as the switch contact is just making the connection).

I have checked an exact switch type that is servicable and I get a .6 ohm resistance when the switch is closed.

Back to my original thinking...why could this high resistance on the switch not be creating my problem?

-Jim

Why don't you just try changing it out? 

[Mach7]

I did actually. (change out the switch...actually just disconnected it altogether)..

According to Leo, the only way that this board would overheat is due to an overcurrent situation. He suspects a short somewhere, or a pot resistance level out of tolerance. These 836x boards have no current limiters installed, so if you don't catch it quickly the board will just overheat and fry.....like the last board I had installed.

The fact that it happens so intermittently leads me to the only problem I have found so far in the setup...and that was the avionics 1 switch. This switch sometimes makes a firm close contact and sometimes it does not. Sometimes the switch contact will close and then vibrate to a position between closed and open, creating a lot of noise in the system.

I spent the last day checking and double checking all the wiring and the remaining switch connections and contacts....everything checks out so far.

The pot values have been sent to Leo, (I actually tabulated them here as well), so I am waiting to hear back from him sometime next week.

It is so imtermittent that I might not be next to the board next time it overheats in the event the switch was not the issue.

So far the board has been operating fine...however I have said that before as well, and then all of a sudden it spikes and overheats.

[iwik]

James,
there is one thing that springs to mind is an oscillation starting up
randomly. An oscilloscope would be your friend here. Checks on supply lines and analogue inputs to see if any other signals are happening at the same time as overheating.
Les

[KyleH]

..

I am getting an ohms reading of between a zero load and close to 200 ohms, (as the switch contact is just making the connection).

...
Back to my original thinking...why could this high resistance on the switch not be creating my problem?

-Jim

Ohm's law.

I = V/R

(I = current in Amps, V = voltage, R = resistance in ohms)

From the above formula you can see that an increase in resistance is a decrease current.
So using your resistance numbers and using 5V as that is a typical supply voltage:

I = 5/200 ohms = 0.025A or 25mA

I = 5/0.6 ohms = 83A.

As you can see, with the switch closed properly, you'd have much higher current through it than with it at 200ohms.
Typically the switch would be connected to the microcontroller with a 10k pull-up resistor to the 5V supply, so that that resistor prevents the large currents that would be present through a switch. Some microcontrollers have this resistor internal to them.
So no the 200ohms will not directly be drawing a high current.

That said, the intermittent contact could be confusing the microcontroller. If its internal pullups are being used, maybe they aren't being configured properly when you have the problem.

[blueskydriver]

Hey Jim,

Sorry for not seeing your reply to my post before now... So, after you did everything (checking connections and etc), and went directly to the computers USB port, you're still having this issue? I thought when you hooked it directly to the PC that took care of it? If not, how long was it before it showed the same problem again with being connected to PC USB port?

I do understand you're having the poor contact with the switch, but let me stick with USB port a bit longer, by asking this:

1. How long is you USB cable from the card to the PC (do not use hub for now)?
2. Is there anything that could be laying across the USB cable?
3. What type of USB cable is being used (brand)?
4. Are there any other power source cables near the USB cable that could be causing an RF interference?
5. Is the card's ground based on the USB connection, if not where is the ground source?

I wil have a few more questions after I do some reading on your card...

John

[blueskydriver]

Okay, I read up on your card and here are a few more questions:

1. Knowingly, you checked each wire and made sure they're connected, but is there a chance that a switch is connected backwards in the case of a ON-ON switch?

2. Are you by chance using two buttons together on one port?

3. Are you using 24 Gauge wire for all your connections?

4. Since the grounding from the card ports goes back to the USB, I believe that it uses the USB casings ground as a common ground.

5. Are the switches in use metal bodies or plastic covered bodies?

6. The bad Avionics switch in question, is there any chance that it was grounding out in the location it's mounted at, meaning you're mounting the switch to a plastic or metal backing panel?

7. Have you thought about disconnecting everything and going the long way of plugging them in one at a time, and checking the operation, then plug in the next one and so on?

8. Lastly, are you using any diodes to make sure the 5v current only flows in one direction for each connection to the card (this would be overkill for every one, but would prevent any back flows)?

In my opinion, you're USB cable could be shorting out inside the cable itself causing the 5V to go down both sides (positive and negative) of the card, causing the overheat and burnout. Also, I am leaning on the idea that you're getting a cross ground somewhere else. In other words, the grounding of a switch is hitting metal somehow and causing the resistance to go erratic or an over voltage (if it's picking up power by something next to it like an led or bulb of some sort.

I want to add this, but I cannot guarantee the result; you could soldier a shielded 24 gauge wire to the outer metal casing of the card's USB port and soldier the other end to a standard ring connector, then place that ring connector under one of the PC's case screws. Thus, you would pickup the common ground. HOWEVER, if the card's micro controller is reliant upon the PC's USB grounding coming off the PC motherboard, I might not do that. Still, the USB port ground from the motherboard comes through the power supply cable, which is picking up the earth ground through the electrical outlet.

Surely, some might think this is a far stretch, but I had this issue (being erratic or burnng out) with a couple of different type of cards at the same time and wasn't until I grounded the use location to the earth ground that the problem stopped. Case example was my throttle assembly housing; it was Rob who suggested doing this and once I did, no more problems... Heck, he is a guy you should PM about this...he might know what your issue is, as I think he used Bodnar cards back in the past.

Best Regards,

John

[blueskydriver]

Jim,

You said your switches are OEM 2tp1-3, so OEM is like Honeywell or what brand is it?

I attached a link to a Honeywell pdf switch guide:

https://sensing.honeywell.com/index.php?ci_id=50382&la_id=1

Please look at the second page and tell me if it's the same type of switch(s). In your case, it is a 2 pole 1, 2, 3, screw connector...if so, then make sure all your wires are connected correctly based on the keyway location (shown on the switch; the pdf file shows this).

Again, this is to checkout your wiring to make sure a hot wire is not running back into the ground connection, since you're using rockers that work like ON-ON switches.

This is a long shot, but you never know...

John

[Mach7]

       

                 


Hello John,

Yes...I did connect the 836x directly to the computer and have had no problems so far...I am just very suspect that the problem will rear its ugly head again soon. I have gone down this road before, feeling relieved that I have found the problem after hours of sim time, only to find that that I am back into a board overheat situation again.

To answer some of your questions;

1. How long is your USB cable from the card to the PC (do not use hub for now)?

The cable is about 5 feet in length from the PC to the 836x board.

2. Is there anything that could be laying across the USB cable?

No

3. What type of USB cable is being used (brand)?

That is a good question as I have long since discarded the packaging. Needless to say the cables are of high quality.

4. Are there any other power source cables near the USB cable that could be causing an RF interference?

Yes...there is a power bar close by that has outputs (5 volt) to the visual monitors, plus an ethernet hub to send information from the server computer to the 7 client computers for outside visuals.

5. Is the card's ground based on the USB connection, if not where is the ground source?

The cards ground is indeed based on the USB connection

1. Knowingly, you checked each wire and made sure they're connected, but is there a chance that a switch is connected backwards in the case of a ON-ON switch?

I don't think so. The only switch that would have an on-on connection would be the landing gear selector lever. The landing gear selector switch has two positions of up and down, these are both closed connections, however are programmed through FSUIPC. I have never had an issue with the landing gear selector switch as it was the first one to be programmed into the board and has been true and tested prior to my problem.

2. Are you by chance using two buttons together on one port?

No

3. Are you using 24 Gauge wire for all your connections?

All wires are of 22 gauge as per leo Bodnars recomendations.

4. Since the grounding from the card ports goes back to the USB, I believe that it uses the USB casings ground as a common ground.

I would agree with you on this point.

5. Are the switches in use metal bodies or plastic covered bodies?

The 2tp1-3 switches incorporate a plastic body.

6. The bad Avionics switch in question, is there any chance that it was grounding out in the location it's mounted at, meaning you're mounting the switch to a plastic or metal backing panel?

I would have to say no. Although the switch is situated in a metal backing panel, there is no possible way that it would be grounding out on the frame or otherwise due to the plastic construction of the switch body.

7. Have you thought about disconnecting everything and going the long way of plugging them in one at a time, and checking the operation, then plug in the next one and so on?

Yes...I have actually done this a number of times. Everything works perfectly and no problems are present. The only variable here is the suspect switch.

8. Lastly, are you using any diodes to make sure the 5v current only flows in one direction for each connection to the card (this would be overkill for every one, but would prevent any back flows)?

No I am not...but that might be a good idea regardless of my current situation.

Leo also suggested to check the analogue inputs for any that are showing very low resistance ( sub 20 ohms ) and add a low value resistor if needed.  If you note the resistance values that I have tabulated on my earlier post(s), all values exceed this level...so I do not think this is the problem area.

The switch in question is a honeywell product and is definitely and off and on contact.

I have talked to Rob about this problem and he initially thought it was the Open Cockpit boards that were finding a ground through the 836x board. He suggested isolating the OC boards from the 836X by utilizint a separate power supply and also soldering a ground from each OC USB input back to the independent 5 volt power supply, (the one used to power the boards, not the USB hub).

This did not alleviate the problem, but I still believed the OC boards were the cause of the problem.

I employed Leo to modify an additional set of engine gauges to operate under his CanBus arrangement, thereby eliminating the OC boards and possibly my problem.

This of course worked perfectly up until last week when the board began getting warm again...therefore the OC boards were not the solution to my problem.

I have since disconnected the 836x output from the hub, (the one that also included the vhf nav heads, rudder pedals, and mcp), and placed it directly to the computer USB output.

Since this time everything has worked fine....however being still suspicious, and in no small part an email from Leo advising that the only way this board would overheat was due to an overcurrent situation....he suggested checking values and looking for shorts. The only thing I found was that avionics switch...

So I am at this point so far.

-Jim

[blueskydriver]

Jim,

About to head off to bed, but I thought about this, where is your card mounted and is it isolated from other cards and/or are the soldier points/pins on the backside of the card above any possible contact points?

Also, have you thought about checking each port for the output voltage of 5V? I believe you checked for continuity and ohms already, but to check for voltage you'd have go about it a little bit different. First, you disconnect the negative wire from the port that a switch is plugged into, using your multimeter, you would place the red lead (better if you have alligator clips) on that negative wire from the switch. Next, you cut a small section of 24 gauge wire for a jumper and connect one end of it to the black lead of the meter, then connect the other end into the negative port on the card for that switch.

In other words, you're connecting your meter as an inline tester, and you set your meter to the 20 volt range (or whatever the setting is closest to 5V, but as along as it's above 5). So, once you trigger a switch for that particular port, it should see 5V when turned on. Even if you have an ON-ON, you should still 5volts either way you press the switch because you are measuring on the negative or the return. This would take a while to do because you would have to move through each port one by one, moving the jumper and the red lead to each negative side of any port.

Why do all of this? Well, you do this to check and see if you're getting any over voltage spikes while checking each and every switch. You can wiggle and flip the switch back and forth a few times to see what the voltage is doing. Yes, just checking the continunity is basically the same, but that only checks the switch, while checking the voltage inline still requires the card too be hooked up and working, thus it'll help detect any spikes or drains.

Lastly, will you please post a pic of where your card is mounted (showing the card in it's natural working state).

John

[blueskydriver]

Hey Jim,

I was typing while you were...lol, so you answered a lot in between this time. So, based on your answers, I think it is/was the hub and as you said it all seems fine now. My thoughts are this:

1. What is the model number, brand, USB version number (could be 1.0, 1.1, 2.0 or 3.0 and output amperage on the hub (for amp output look at the power supply)?

2. Just based on the other items connected too the hub, can I assume they're drawing power for 7-segment displays and leds as well? If so, your hub is asking for a lot of amps and your power supply for the hub is providing it, but there might be a coefficient occurring with heat build up to the port where 836X card and your getting an over amperage situation.

I mentioned before about using power strips and how they turned brown or how one item that does not need a lot of amps is plugged into one that does and the low amp starts having problems or gets overheating too the burnout stage. Thus, I believe your hub is/was doing this and the 836X card is the lower amp item connected to the hub, but getting more then what it needed because of the other items on the hub.

3. Leo is saying what I am saying in the over current which is going to be based on amps; although, it could be voltage, but you'd have to be pushing some serious over voltage like 12 volts or higher.

I also agree with what he says and that is why I posted in my last post about going through the inline test with each port/switch, which would take some time, but worth it in the end.

However, if it's working normally now being that it's connected directly to the PC, I would leave it be and only exchange the bad switch you found. Still, like any good sim builder you want some reassurance. Therefore, you need a USB Hub that has over current protection, but it would be nice to find one with an overheat protection switch with a probe that you could attach to the card, then if it reaches a certain temp, it would trip the switch and shutoff power to the hub itself. I have been surfing too find something, but might have to wait until tomorrow...getting sleepy and in bed already...ipad about to hit my face by dozing off...lol.

John

[Mach7]

Hello John,

The card is mounted on four small rubber washers so that is sits above the 6 x 10 inch mounting board.

The card was clean when it was installed, that is to say no metal particles or shavings on the bottom of the board that would cause it to short out.

My board set up is such that I have stacked terminal blocks sitting adjacent to the board with all the wires running from the board to the connections on the blocks. The terminal blocks are color coded and numbered to correspond to a position on the 836x board. This allows me to simply connect a switch, pot, etc to the terminal input without having to disturb any inputs that have already been attached to the board.

I have not yet checked each port for voltage. This would apply to only the pot outputs anyway as the other board connections are basic switch functions. (I have attached a pic of my board inputs and outputs).

Some additonal answers to the below questions;

1. What is the model number, brand, USB version number (could be 1.0, 1.1, 2.0 or 3.0 and output amperage on the hub (for amp output look at the power supply)?

The hub is a TRENDnet TU2-700. Here are the particulars;

Compliant with USB 2.0 and USB 1.1 Specifications

-Fully Forward and Backward Compatible with USB 1.1 Devices
-Supports all USB speeds: High-Speed (480Mbps), Full-Speed (12Mbps) and Low-Speed (1.5Mbps)
-Switches to the Peripheral's Highest Supported Speed Automatically
-Supports up to 127 USB Devices
-Supports Suspense and Resume Operations
-Compatible with Windows 7/Vista/XP/2000/ME/98SE, Linux and Mac Operating Systems
-USB 2.0 A-B cable included (60cm /2ft.)
-Supports Plug & Play and Easy Installation 

Specs

-Manufacturer Trend Net
-Power Consumption: 500mA (max) per port
-Power Adapter: 5V DC, 2A External Power Adapter
-Max. Devices Supported: 127 (daisy-chaining with other USB hubs)
-LED Indicators: Power
-Dimensions: 80 x 50 x 10 mm (3.14 x 1.95 x 0.4 inches)- See more at:

2. Just based on the other items connected too the hub, can I assume they're drawing power for 7-segment displays and leds as well? If so, your hub is asking for a lot of amps and your power supply for the hub is providing it, but there might be a coefficient occurring with heat build up to the port where 836X card and your getting an over amperage situation.

This could be a distinct possibility as well. I do have my MCP hooked up to the same hub which in turn has 7 segment displays.

3. Leo is saying what I am saying in the over current which is going to be based on amps; although, it could be voltage, but you'd have to be pushing some serious over voltage like 12 volts or higher.

I also agree with what he says and that is why I posted in my last post about going through the inline test with each port/switch, which would take some time, but worth it in the end.

However, if it's working normally now being that it's connected directly to the PC, I would leave it be and only exchange the bad switch you found. Still, like any good sim builder you want some reassurance. Therefore, you need a USB Hub that has over current protection, but it would be nice to find one with an overheat protection switch with a probe that you could attach to the card, then if it reaches a certain temp, it would trip the switch and shutoff power to the hub itself. I have been surfing too find something, but might have to wait until tomorrow...getting sleepy and in bed already...ipad about to hit my face by dozing off...lol.

Again John, thanks for your input. It is very helpful and I think that by removing or disconnecting the switch and tapping the 836x board directly to the computer, bypassing any hub(s), this might make the setup happy. Only time will tell.....hopefully Leo will chime in tomorrow with some additonal information, I will post something then

Thanks again!

-Jim

[Mach7]

@Joh, Bob, Les, and Kyle,

Again guys thanks for your inputs. I received an email back today and here are some of the preliminary thoughts...

You were all correct, the malfunctioning switch would not create an issue with the board as it is nothing more than a poor contact.

When they reviewed the pot values, they felt that the resistance of the flap selector at zero may be a bit too low, (it was 36.9 ohms) and suggested bringing it up to 200 ohms with an inline resistor.

John, you were onto something in your last email when you said;

Just based on the other items connected too the hub, can I assume they're drawing power for 7-segment displays and leds as well? If so, your hub is asking for a lot of amps and your power supply for the hub is providing it, but there might be a coefficient occurring with heat build up to the port where 836X card and your getting an over amperage situation.

The last thing they mentioned is that there may be a possibility of backfeeding thought the USB connection causing the board to overhead. The backfeeding may be caused by another device that contains LEDs....I believe this is what you were saying in the text above.

I have two HUBs, each one contains a device that has LED's..the OC boards on the first HUB and the MCP ont he second, I have had issues with the board at each of these locations thus far.

Having said this, everything is working fine so far with the 836X connected directly to the computer,

Time will tell!

-Jim

[blueskydriver]

Hey Jim,

That's great news! By knowing that this is possible coming from Leo, it helps too really narrow it down; hopefully, your system will be stable without your card overheating anymore.

I did think about a fall back protection method and that is too use an aquarium (also other uses) type heat sensitive relay. Basically, the unit has a probe that you could place on the card and you would set up your temp range, then the device would shutoff the power to the card via the powered hub or at least reduce the amount because you would be turning the hub power supply off.

Here is just one example:

http://www.ebay.com/itm/Pre-wired-110V-220V-F-C-Thermostat-Temperature-Controller-Control-Relay-Sensor-/381157645765?_trksid=p2141725.m3641.l6368

There are many different types, but most are relatively inexpensive, so you could try one or two types to find the best one.

After reaching this point of helping you, I never thought of the uses of a temp power outlet relay before, but now I am thinking of all sorts of ideas, so thanks for giving me the opportunity too help out...

Best Regards,

John   

[Mach7]

Hello John,

Actually just received another email from Bodnar Electronics..I must have misread his last text as he says that the possible feedback could occur if the board is also used to power LED's...so he feels the board overheat is probably not associated with the HUB or its associated equipment.

Having said that, I still think the HUBs had something to do with it...time will tell if I am correct or not.

-Jim