SoliForum - 3D Printing Community — three voltage LED's ? supposed to be on or off?

Re: three voltage LED's ? supposed to be on or off?

2017-07-30T16:05:12Z

joealfadog wrote:

Thanks MJF, I'll do that.
The LCD does display the two black lines (which suggests it's at least getting some form of power) when powered on which some folks say is a sign that the firmware has been corrupted, but no backlight, and no internal illumination lights on the light bar either. Is there a way to flash the firmware to the SD card without the board, then re-insert it? Or does the firmware reside on a the board?
Forgive my naivite. While I'm an aeronautical engineer by trade and can achieve some pretty miniscule surface mount and hot-air PCB repairs if needed, other skills acquired over the years, Software and controls programming still baffles me a bit.
It would be truly sad to buy a board and find it's something else, Especially on a printer so long in the tooth already.
I really appreciate your help and patience.
-Joe

Joe, no problem, happy to help.
I suspect that you are correct that the voltages are correct, and that it is a firmware corruption issue, but wanted to check out everything I can think of before you give it up.
I have seen on these displays that if the contrast voltage is not correct, then you will get black bars. I was / am hoping you may see a blown resistor.
-Mark

Re: three voltage LED's ? supposed to be on or off?

2017-07-30T15:51:44Z

Thanks MJF, I'll do that.

The LCD does display the two black lines (which suggests it's at least getting some form of power) when powered on which some folks say is a sign that the firmware has been corrupted, but no backlight, and no internal illumination lights on the light bar either. Is there a way to flash the firmware to the SD card without the board, then re-insert it? Or does the firmware reside on a the board?

Forgive my naivite. While I'm an aeronautical engineer by trade and can achieve some pretty miniscule surface mount and hot-air PCB repairs if needed, other skills acquired over the years, Software and controls programming still baffles me a bit.

It would be truly sad to buy a board and find it's something else, Especially on a printer so long in the tooth already.

I really appreciate your help and patience.

-Joe

Re: three voltage LED's ? supposed to be on or off?

2017-07-30T01:15:33Z

joealphadog, so we know power is getting into the board, the resistors are not open and all 3 leds are lit (12, 5 and 3.3 volt rails). My only other suggestion would be to look on the back of the LCD screen, find the model of it, look up the datasheet on the internet, probe the power pins there to make sure that the correct power has made it to the LCD. If that all works out, then something else is very wrong, and we don't know enough to diagnose it.

Thats about all I can do to help. Come back and let us know what you find or do.

Re: three voltage LED's ? supposed to be on or off?

2017-07-29T15:56:31Z

RV 3, 4, 5 are just black and have no value written on them. All three show some continuity and are not open (Around 7-50 on the 20K Ohm scale I f I'm reading it right). No power and power supply and load side disconnected.

Re: three voltage LED's ? supposed to be on or off?

2017-07-29T15:17:32Z

I'll check the resistance of RV# resistors, but If I understand correctly, were they blown, I'd have no LED's?

Re: three voltage LED's ? supposed to be on or off?

2017-07-29T11:43:52Z

There was a third gen board that I never actually saw. But it is possible this could be that board as well. There would still need to be some sort of over current protection on each rail, it is just a matter of finding where they are located on the board.

Re: three voltage LED's ? supposed to be on or off?

2017-07-29T04:53:18Z

This may be a wonderful opportunity to convert to RAMPS, as I think the cost will be less than a new xyz board ( saw one on eBay for 99 dollars.). Unless Carl or someone else has more ideas....

But...if you have a multimeter, you could measure the resistance of those RV* resistors and see that there is some resistance, not open. May be 0 as Carl suggests, or some other value. But not open or infinity/ overload depending on the meter. If overload/infinity/open, then the resistor is blown.
DO THIS WITH POWER OFF and UNPLUGGED.

P.s. can you read that is written on top of one of those resistors.?

Re: three voltage LED's ? supposed to be on or off?

2017-07-29T04:31:18Z

Sooo...Looks like the only forward step is to try flashing and then buy a board and hope that was it? ...when I went to do the Davcinci 1.0 reset, the first instruction was to input a command in the arduino app and look for the LCD to cycle off , then back on with another command. How can this be done if there is no lcd light to begin with?

Also, Thanks very much to both Carl and MJF. I read through countless pages of reference to the current limiting diodes, not understanding if the issues were really anything like what I'm seeing here. As I read back , I now can see that each of them had at least some function as well as power missing on at least one voltage circuit.

Your help and clarification is much appreciated.

Any other thoughts on how to discern if the board is toast?

Joe

Re: three voltage LED's ? supposed to be on or off?

2017-07-29T01:58:46Z

carl_m1968 wrote:

The ones marked RV# are actually zero ohm resistors that are used as fuses due to their wattage rating rather than their resistance. Resistors DO NOT filter. The filter is done by those large electrolytic caps that are on each rail. His board os one of the second gen boards and it is laid out a bit different from the one that is on the voltivo site.

EDIT - Not sure I fully agree. In this circuit it appears to me that the RV* bridges voltage to ground, along with the small cap. To me that is an RC network, along with the bigger cap. But, I will defer to carl, as he is more familiar with this board

Re: three voltage LED's ? supposed to be on or off?

2017-07-29T00:51:06Z

mjf55 wrote:

RV3, RV4, RV5 along with C4 C5 and C6 are noise filtering circuits and are not the cause of your problem. R15, R16, R17 are current limiting resistors for LEDs D1, D2, D3. all that appears to be working.
Which wires go to your heater element? Is it J4?
EDIT:So the best that I can see is that there are no zero ohm resistors on this board. But if carl differs, I will differ to him.
What are the markings on chip Q1. My old eyes can read the info.
EDIT2 - So you can see from this link https://forum.voltivo.com/images/R271.jpg , that the zero ohm resistors (R47 and R57 ) on the 1.0A board and what they look like. They , or ones like it , are not present on your board
EDIT3 - Never mind about Q1. Found another photo of your board. It is B55NF60L with is a power mosfet to turn on your heating element.

The ones marked RV# are actually zero ohm resistors that are used as fuses due to their wattage rating rather than their resistance. Resistors DO NOT filter. The filter is done by those large electrolytic caps that are on each rail. His board os one of the second gen boards and it is laid out a bit different from the one that is on the voltivo site.

Re: three voltage LED's ? supposed to be on or off?

2017-07-29T00:46:52Z

RV5 is the 12 volt fuse, but if the LEDS are all on then that means you have all three power rails going into the board. That means your issue is with the actual board and could be any number of things but if it is just dead then chances are the firmware has crashed and the machine does not know what to do. You could reflash it if that is the case. Or there is an issue with voltages further into the board. If that's the case then you are looking at a new board or a complete logic swap.

Re: three voltage LED's ? supposed to be on or off?

2017-07-28T23:53:21Z

J4 is the heater

Chips 01 and 02 are makred as follows: B55NF06c, GE051 V3, CHN 2105

Re: three voltage LED's ? supposed to be on or off?

2017-07-28T23:14:45Z

RV3, RV4, RV5 along with C4 C5 and C6 are noise filtering circuits and are not the cause of your problem. R15, R16, R17 are current limiting resistors for LEDs D1, D2, D3. all that appears to be working.

Which wires go to your heater element? Is it J4?

EDIT:So the best that I can see is that there are no zero ohm resistors on this board. But if carl differs, I will differ to him.
What are the markings on chip Q1. My old eyes can read the info.

EDIT2 - So you can see from this link https://forum.voltivo.com/images/R271.jpg , that the zero ohm resistors (R47 and R57 ) on the 1.0A board and what they look like. They , or ones like it , are not present on your board

EDIT3 - Never mind about Q1. Found another photo of your board. It is B55NF60L with is a power mosfet to turn on your heating element.

Re: three voltage LED's ? supposed to be on or off?

2017-07-28T22:56:13Z

Are we talking about C6 and RV5? lower left?

I do have all three red leds when the board is powered -up.

Joe

Re: three voltage LED's ? supposed to be on or off?

2017-07-28T21:53:27Z

joealfadog wrote:

Is the problem with the brass brush that it shorts the positive side of the heater rod to ground?

What usually happens is the insulating sleeves do not go all the way down to the body of the heater leaving power and ground exposed. The brass brush being metal creates a short here and blows those fuses. They should have a warning sticker telling you not to use the brush while the heat is on.