How to verify Transistor is working for Z Sensor

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How to verify Transistor is working for Z Sensor

Postby pbtalkAM » 2017-Apr-Wed-23-Apr

Long story short...had an accident/issue and noticed Z sensor is no longer working. No matter the direction it is connected, the light doesn't turn on anymore when near metal. Accident definitely caused huge pulling on the probe to where the tension was so high it actually disconnected *sad face* I didn't notice it until I had recovered (or so I thought) from the issue, and the print head slammed into the print bed and kept going lol.

So I've done some reading on this website to know that likely, the conductor snapped on the inside when it was pulled under high tension.

So I did more reading on this website and found that I need to be careful and determine if that transistor has been fried as well. I went to this site for a schematic and found the ground pin.
http://www.makersbox.us/2015/04/ken-ver ... -stop.html

Then I tried to measure PIN2 vs GND and I didn't get 5V.
Is something wrong? When it comes to micro-controllers, I don't want to assume because I know that maybe the voltage isn't even turned on. Can I try anything else - I can't easily hookup to the transistor to force a 12V connection to then see if there is 5V (did I just answer my own question?) that is opened. I just assumed that I should be able to probe the voltage as long as I use a common ground. the 12V connection is only needed to open the gate so current will flow.

What can I do to see if the transistor is working? I mostly don't want to order another induction probe to have it break, and, if i need to order a new printrbot board (I have rev F4 which looks like it doesn't have a current limiting resistor to prevent a short), I do it now vs in the future. FYI I have SOME electronics knowledge, but assume that I don't if any response becomes complicated :-)


EDIT before I even press "POST":
I restarted the system, and now I get 5V. So its just a probe? Geez 25 bucks, any drop in replacements from amazon? I saw other posts, but I'm not looking to upgrade or enhance, I just want a drop in replacement and don't need extra distance because I print directly to an aluminum bed.

Edit:
NM i found it on amazon, but can anyone tell me what size pin connectors these are so I can rebuild it myself? The part comes with frayed wires and I want to match the connectors from the PB Board (assuming that the board itself is perfectly fine)
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How to verify Transistor is working for Z Sensor

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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Mon-19-Apr

Boss,
I have the same issue, many thanks for the education on the subject.
The transistors arrived today, and I expect a replacement sensor by the end of the week.

What I would like to know is the 'why' of it all?

Also if there is a schematic of the F5 board available. Would like to learn how this whole thing works.

Thanks in advance.
Jack Crow aka Radio Mike
Virginia Beach VA
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Re: How to verify Transistor is working for Z Sensor

Postby RetireeJay » 2017-Apr-Mon-20-Apr

Jack Crow wrote:Also if there is a schematic of the F5 board available. Would like to learn how this whole thing works.

https://github.com/Printrbot/printrboard/releases/tag/revF5
After you download the zip file, unzip it. Then use Eagle software to read the file; Eagle is free for non-commercial use.
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Tue-06-Apr

Jay,
Thanks for the pointer. Will have to get this Eagle SW you mentioned.
Will follow up when I know more.
Thanks
Jack Crow aka Radio Mike
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Tue-19-Apr

Boss,
Some follow ups.

Went and looked up the z probe by it's P/N.

L12A3-4-Z/BY

There is a page out there with a 'test circuit'.
It shows how to hook it up on the test bench. Did that.

The last time I went to tie a link to this list, I got a warning from the system, so search by the P/N and you should find it.

Dismounted the probe from the printer.

Found that BP installeda handy 3 pin connector heat shrieked to it's mate behind the hot end.
The far end of that wire connects to the printers F5 board.

Anyhow connected my 'dud' sensor as per the drawing.
The red light works fine.
It's black wire that is supposed to change state when the sensor is tripped.
Did not source voltage in either the on or off state.
Did not work as an 'open collector' type output.
The drawing was vague on that subject.
On the scope I can see a slight change in the level, but not enough to turn on any down stream transistor (FET).

Went to see about trying to fix this probe.
The only way to open this probe seems to require destroying it.
So that is out for now.

Have a new part coming from PB hopefully this week.
Have new transistors in from Digikey.

With a little bit of luck I can be back on the air this weekend.

Again, thanks all for the insight into this problem
Jack Crow
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Re: How to verify Transistor is working for Z Sensor

Postby pbtalkAM » 2017-Apr-Thu-03-Apr

Update on my end - bit the bullet (bought from PB store, but I bought more backup from amazon).

New Probe came in, doesn't work, and light doesn't turn on. I'd be surprised if I got a dud probe, now I'm thinking the Transistor was dead, and the 5V measurement literally had nothing to do with the function of the transistor. As I look at the diagram, the 5V just shows to me that the microcontroller is working to output the 5V as expected. I need to actually trigger the transistor to activate, can't verify its function statically.

Based on your advice, I will look into verifying the probe works with the Scope, and then also read about how to test a transistor (looks like lots of resources online, not too bad).

My biggest fear is that if the Transistor is dead, I need to buy a new printrboard because, unlike you, I barely have the skill to solder through-hole, let alone surface mount lol. And not just a surface mount, but a surface mount with a current limiting resistor....and a new printrboard (looks like they have rev F6) is going to run 70 dollars..

Are you going to slap a resistor on there as well so you don't run into the same issue?
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Re: How to verify Transistor is working for Z Sensor

Postby RetireeJay » 2017-Apr-Thu-06-Apr

It's unfortunate that they show an FET transistor in the schematic diagram. If you look up the part number from the Bill Of Materials, you find that the transistor that receives the signal from the probe actually is a bipolar transistor with built-in resistors. So there's really only one part to replace.

Several people posting here have said that shops that repair cellphones may be willing to do the soldering work for you if you come to them with all the appropriate parts. The transistor itself is very cheap.

The transistor, however, has nothing to do with powering-up the probe. So if you purchased a new probe and the light on the probe never comes on, it is not the fault of the transistor. I'd rather suspect that the probe is not receiving the appropriate power. Some probes run off 5V, some run off 12V. Most versions of the Rev F board have a jumper where you can select which voltage feeds the probe.
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Re: How to verify Transistor is working for Z Sensor

Postby pbtalkAM » 2017-Apr-Thu-20-Apr

RetireeJay wrote:It's unfortunate that they show an FET transistor in the schematic diagram. If you look up the part number from the Bill Of Materials, you find that the transistor that receives the signal from the probe actually is a bipolar transistor with built-in resistors. So there's really only one part to replace.

Several people posting here have said that shops that repair cellphones may be willing to do the soldering work for you if you come to them with all the appropriate parts. The transistor itself is very cheap.

The transistor, however, has nothing to do with powering-up the probe. So if you purchased a new probe and the light on the probe never comes on, it is not the fault of the transistor. I'd rather suspect that the probe is not receiving the appropriate power. Some probes run off 5V, some run off 12V. Most versions of the Rev F board have a jumper where you can select which voltage feeds the probe.


Hmm I'm looking at the schematic and I see that now; however, I've never changed the jumper and its the PB drop in replacement, so why should it be different all the sudden?
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Fri-20-Apr

Boss
Follow ups.
Got the transistors in.
Got the new probe in.

Installed all the new parts onto and into the Simple Metal.

No Joy.

Got a new failure mode.

Went to calibrate the probe.

Could move the Z by hand and see that the LED on the back of the probe would turn on and off in proximity to the print plate.
Went to print a test part. The X and Y do their thing.
The Z goes up and comes down, and never stops.

It rams the print nozzle into the plate until the coupling for the z axis screw pops off the motor.
Tried the old setting of -1.5, new settings of -5 and +5.
Each time it ramed into the plate after detecting.

It's late for me. Im exhausted, hungry, and aggravated.
Skipped dinner to get this thing working, and it's determined to keep failing.

In the morning Im going to do a 'buzz' check on the wires, make sure the black, brown and blue have 100% continuity back to the circuit board.
If I have to will tip this thing on it's back and see if the transistor is changing state when the sensor is tripped.

May have to get that software package and see what else is between the transistor and the uProcessor, I suspect little else is in the signal path.
If the change in state is getting to the micro I suppose I could re flash the firmware, some how I doubt that is going to help.

Worst case I order some micro's.
Damm I wanted to make stuff this weekend and it's still broken.

Jack Crow aka Radio Mike
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Re: How to verify Transistor is working for Z Sensor

Postby RetireeJay » 2017-Apr-Fri-21-Apr

Easier than tipping the bot on its back and probing with a voltmeter is to use the M119 command. It will tell you the current state of the X, Y, and Z position sensors (two switches and a probe). If you see the light on the probe change state but repeating the M119 shows no change, then the first place to check is the wiring between the probe and the board. Only then, if wiring is known good and the M119 stubbornly refuses to change, is it time to do the voltmeter thing. In very rare cases, reflashing the firmware might cure an inability to "see" the probe's state - but reflashing is usually not necessary, and runs a small risk of making things worse.

And no, there's nothing in the signal path between the transistor and the microprocessor. Not even a pull-up resistor because it's internal to the uP. You can find the schematic in PDF at reprap.org/wiki/printrboard (but it might not be for your version of the Printrboard) or download the actual schematic from Github (I posted a link to that recently in this thread).
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Fri-21-Apr

RJ
Thanks for the data.
This will be tasking for the morning.
Will follow up with results.
Jack Crow
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Sat-10-Apr

RJ
From your note....

"And no, there's nothing in the signal path between the transistor and the microprocessor. Not even a pull-up resistor because it's internal to the uP. You can find the schematic in PDF at reprap.org/wiki/printrboard (but it might not be for your version of the Printrboard) or download the actual schematic from Github (I posted a link to that recently in this thread).

Have to admit I used my own crude methods.

Tested the wire harness from the sensor connector behind the hot end to the pcb.
All were good.

Powered up the unit and proved the probe LED and signal were working properly.

Was able to prove the signal made it's way to the Base of the new transistor.
That is where the magic came to a halt.
Saw only the slightest change at the Collector.

Ok perhaps I had a bad transistor.

Changed it out again.

No difference. The Collector voltage did not move.
This is concerning. It shows that there is enough current in the micro to trash the transistor the first time it's turned on.

Im beginning to think something let go hard in the microprocessor.

By the end of the day I will have a few of the micro's on order and perhaps some of the motor drivers, just as spares.

In the mean time, Im open to ideas.

Jack Crow aka Radio Mike
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Re: How to verify Transistor is working for Z Sensor

Postby RetireeJay » 2017-Apr-Sat-11-Apr

What was the voltage you were reading on the collector of the transistor? If it was very low, like fractions of a volt, then it's possible that the transistor is fine but the pull-up resistor inside the uP is not working (or not programmed to turn on). It's virtually impossible for the uP to send an overload of current to the transistor sufficient to burn it out.

So this might be a case of needing to re-flash, just to eliminate the possibility that the pull-up resistor is not being turned on in firmware. Be careful to find the right version of firmware. There are loads of different versions out there. Firmware for Rev D boards (like Unified) is definitely not compatible with Rev F boards.
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E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Sat-12-Apr

Boss
Answers interlaced in your note....

"What was the voltage you were reading on the collector of the transistor?

(That is the problem, it is stuck high, about 4.89V give or take a little bit.
No sign of a shift when the probe is operated. I can see the probe voltage on the base change.

Was thinking of subing in a 2N7000 FET, have a good supply of them.
Even if they are TO92 cased.)

If it was very low, like fractions of a volt, then it's possible that the transistor is fine but the pull-up resistor inside the uP is not working (or not programmed to turn on).

(Nope, stuck high.
Even measured on the uP pin.
That is why I was concerned that the transistor was destroyed at the first turn on.

Ive started to wonder if I got the right transistor.
Will go back and see.)

It's virtually impossible for the uP to send an overload of current to the transistor sufficient to burn it out.

(had me puzzeled as well.
The longer I pondered this, the less likely it seems.
Was thinking of manually pulling that line down.
If the micro was bad, then all that current would shunt and kill it dead.
Get 1500 ohms in series and probe that point to ground and see what happens.
No great loss.)

So this might be a case of needing to re-flash, just to eliminate the possibility that the pull-up resistor is not being turned on in firmware.
Be careful to find the right version of firmware.
There are loads of different versions out there. Firmware for Rev D boards (like Unified) is definitely not compatible with Rev F boards.

(What I have is a Rev F5.)

Will let you know when I have this done.

Thanks for the tips.
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Re: How to verify Transistor is working for Z Sensor

Postby RetireeJay » 2017-Apr-Sat-13-Apr

Jack Crow wrote:That is the problem, it is stuck high, about 4.89V give or take a little bit.
No sign of a shift when the probe is operated. I can see the probe voltage on the base change.

That's weird. What are the "on" and "off" voltages you measure on the base? Is the Emitter solidly connected to ground?
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Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Sat-17-Apr

Boss,
Im back.
To answer your question...

That's weird.
(Yupp no kidding.)

What are the "on" and "off" voltages you measure on the base?
(Open is .003 and in the presence of metal 12.66v, so Im real happy with the new probe.)

Is the Emitter solidly connected to ground?
(Yes, stays at zero no matter what.)

Did the trick by touching the C point with 10k ohms to ground, so it pulls down just fine.
For the moment Im going to say that the micro is not bad.
Perhaps I ordered the wrong transistor.

For the moment Im going to tack in a 2N7000 and see if it solves my issues. Use a similar circuit on my APRS conversion radios.

Standby for more news.
Jack Crow
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Sat-17-Apr

Boss
According to the above article I did buy the right transistor.
Just installed a 2N7000 onto the pads, was not easy.
It now flips the line to the micro just fine.
Now to put the printer back into place and see if it works.
More when I know more.
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Sat-18-Apr

Boss RJ
The 2N7000 FET worked just fine.

When the probe gets into range, it flips the bit into the uP and the unit works as intended.

Rather than trying to drive the hot end into the base, it now senses the plate.
Working with the M212 adjustment to see how various test prints go.

Did rip up the Kapton tape cover a bit learning where the limits are.
Small price to pay to have my unit back on line making parts I need.

Many thanks to you and the team here for support, education, and insight.

Let me know if I can return the favor some day.

Jack Crow aka Radio Mike
Virginia Beach VA
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Re: How to verify Transistor is working for Z Sensor

Postby RetireeJay » 2017-Apr-Sat-18-Apr

Just a caution: I haven't looked up that FET, but the gate of your FET is connected directly to the wire going to the probe, i.e. several inches of wire going off the board are connected to the gate. If there's any possibility of static buildup on that wire (like if the probe is not fully connected) then it's possible to damage the gate by high voltage discharge. It takes much less than the kind of spark you get when walking across a dry carpet in the winter.

I'm really mystified as to what went wrong with the bipolar transistor.
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Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-Apr-Sat-18-Apr

Boss RJ

From your note, answers interlaced...

Just a caution: I haven't looked up that FET, but the gate of your FET is connected directly to the wire going to the probe, i.e. several inches of wire going off the board are connected to the gate.

(IF the FET is good, it's a very high Z input point, so it won't load the probe. I use a similar design on APRS conversion radios I make for clients. Usually I put a 1M ohm resistor in line to the Gate just to make sure, but direct connection works as well.)

If there's any possibility of static buildup on that wire (like if the probe is not fully connected) then it's possible to damage the gate by high voltage discharge.

It takes much less than the kind of spark you get when walking across a dry carpet in the winter.

(You have that right.)

I'm really mystified as to what went wrong with the bipolar transistor.

(If you wish I can send you the reminder. I got ten and went through three proving they don't work.
There is an SMT edition of the 2N7000 will try and look that up and see if it works with the pads of the pcb.

Anyhow, made four test prints. Adjusting the M212 value.
The third was fairly good.
Number four was that .25mm too far.
Looked ugly.
Went back to the prior setting.
Have the unit cranking on some parts that I made before, kind of a A vs B comparison.
Suspect it will work well for a good long time.

Again, thanks for the information and support.
Jack Crow
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Re: How to verify Transistor is working for Z Sensor

Postby RetireeJay » 2017-Apr-Sat-20-Apr

I'm glad you got it working. :D

There's not much point in my looking at one of your duds. I would not be able to discern the cause of failure. So let's just be happy you have your printer working and move on.
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Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
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Re: How to verify Transistor is working for Z Sensor

Postby pbtalkAM » 2017-May-Tue-23-May

so time for me to take my thread back.

Didn't realize that probing a digital transistor (transistor with resistors) was going to be a little limited. That said, I couldn't figure out why it shouldn't work...then I got the idea to probe out the 12V.

I disconnected the z sensor, and disconnected the jumper at Z-VSEL to get access...and there is no 12V. It is zero.

Tried 5V...yup. Tried 12V again, nope.

Checked 12V at C21 at Ymotor...it exists!

I then checked voltage at U2...and YUP it exists!
I then found the MOSFET Q2....and YUP it exists! 12V all the way.

Looking at the Schematic, it should all be the same 12V reference line.

Is there a reason I'm not getting 12V on the Z-VSEL pin?????


edit:

getting more bizzare; I turned off the machine, and tried probing the 12V lines on the motorsto see if they beep on a continuity test when I probe each motor...YUP they do! Then I tried to check the motor 12V lines against the MOSFET...YUP they do! Then I tried to check the 12V line against the Z-VSEL...NOPE! Then I tried the MOSFET against Z-VSEL.

I thought maybe the pin got loose, but it seems sturdy? I tried whacking it a little, but its quite solid and stiff. Any ideas?
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Re: How to verify Transistor is working for Z Sensor

Postby RetireeJay » 2017-May-Wed-07-May

As you say, the schematic shows 12V being supplied to one of the VSEL pins for powering the probe. That's not depending on software, nor of any jumper anywhere else. So you've found a defect in your board. There's an off chance you might fix it by using a soldering iron to heat that pin and re-connect it to the 12V bus. If that fails, and it were my board (remember, I'm a EE), I'd take a small-gauge wire (like wire-wrap wire) and connect the vagrant pin to a source of 12V such as one of the heater supply pins.
-RJ
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Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
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Re: How to verify Transistor is working for Z Sensor

Postby pbtalkAM » 2017-May-Wed-23-May

Good News and Bad News.

Good News: I thought about it and figured I should try to bypass. When I saw your recommendation I went for it...and guess what, on the back side, I found this pop (refer to attachment). It looks like somehow the physical connection was broke. The pin is definitely solid though.

Also, the Light turns on when it nearly touches the metal, and turns off when raised from the metal plate. Using M119 I can see TRIGGERED near metal, and OPEN away from metal.

When I click "home" on cura for the Z Axis, it perfectly detects and stops above the plate

Bad News:
When I start a print....the print head still crashes into the build plate. It doesn't seem to detect the build plate again.

Any ideas why it might do this? This is my GCODE.

So close yet so far!

Code: Select all
G21        ;metric values
G90        ;absolute positioning
M82        ;set extruder to absolute mode
M107       ;start with the fan off
G28 X0 Y0  ;move X/Y to min endstops
G28 Z0     ;move Z to min endstops
G29        ;Run the auto bed leveling
G1 Z15.0 F{travel_speed} ;move the platform down 15mm
G92 E0                  ;zero the extruded length
G1 F200 E3              ;extrude 3mm of feed stock
G92 E0                  ;zero the extruded length again
G1 F{travel_speed}
;Put printing message on LCD screen
M117 Printing...
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Re: How to verify Transistor is working for Z Sensor

Postby RetireeJay » 2017-May-Thu-06-May

Just to check, you can manually issue each of those commands and see what happens. In that way you can isolate exactly where the problem is. What you have copied here is the boilerplate code before it's compiled into an actual part's G-code. It might be better to Save the G-code file and open it with a text editor, then use the manual interface to follow the commands.

I don't use a probe, but somewhere in either the G-code or the EEPROM there's an "offset" command which tells the printer a correction from where the probe triggers to where the actual printing should start. Maybe your offset needs to be adjusted.
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Printrbot Plus operational January 2013
Brass threaded rods (5/16" X 18) & nuts for Z axis
GT2 belts & pulleys
Cable chain to reduce probability of fatigue failure in wires
E3D V5 Hot End, 0.4mm nozzle, also 0.8 and 0.25 in use occasionally
PB fan mount + 40mm fan -- using printed mount adapter, not the E3D supplied fan
Injection molded extruder gears
Optical Z "endstop" (custom designed and built)
Have used many pounds of T-Glase filament. Now also doing some work with Ninjaflex SemiFlex
Print on glass with Scotch Craft Stick or other glue stick
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Re: How to verify Transistor is working for Z Sensor

Postby pbtalkAM » 2017-May-Thu-15-May

Yesterday, I actually did check all commands 1 by 1, except for G1 F{travel_speed}. It worked and even zerored the whole way across.

Yeah I discovered this when trying to find the offset. I visually looked at it, and saw I was going to have a ~-1mm offset. When I crashed into the plate, I assumed it was too much and I was surprised I was visually off that much.
The I dropped it down to 0.25mm and it still crashed in the exact same way...which should not have been realistic.

That is what led me down the path of checking each command, but...I didn't check the G-code itself. Would be odd that Cura now is doing it differently. I'll check the actual G-code.


We will see what the G-code says...oddly enough i'm not loading g-code, i'm loading up STLs directly so I know it must be freshly created. Either way I'll double check.
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Re: How to verify Transistor is working for Z Sensor

Postby Mooselake » 2017-May-Fri-12-May

FWIW, Marlin treats G1 (rapid, aka as travel or uncoordinated move) exactly the same as G0 (linear, aka coordinated), G1 is turned into G0 during command decode.

In the real CNC world travel moves are used to move from here to there without any tool use, and without any need to move in a straight line (that's what coordinated means, all axes are moved in a coordinated fashion with equal steps in each segment). You move up to the "safe height" where you won't hit anything and let er rip as fast as you can within the constraints of the travel speed. Coordinated moves means you want the tool to follow a known path, moving all axes together. Think cutting a straight line instead of whatever floats the controllers boat to get from here to there.

If you crash at -0.1 then it's reasonable to crash at -0.25 since you're moving even further into the bed (positive away from the bed, negative towards it), or is that not what you're saying?

Kirk
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Re: How to verify Transistor is working for Z Sensor

Postby pbtalkAM » 2017-May-Wed-22-May

I found the transistor was finnicky - worked sometimes, others not so much. The kicker was that, during testing, I noticed that it actually switched around from Detecting the Metal Plate, to not Detecting the Metal plate. I guess doing a simple wire re-route wasn't the true answer.

So i ordered a new board and a new sensor just to be safe. Sigh so much money.

Anyways, I the new sensor has a different connector. Any idea what I need to bridge these two? I don't know my connector names well, so not sure what is needed to bridge this gap.
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-May-Thu-03-May

Boss,
Im with you. Just had a second board failure in 30 days. This one un related to the sensor issue.

What I did about the sensor connector is to cut the new connector off, and splice on the old one. Heat shrink tubing over the splices to prevent shorts.

Seemed quicker and more reliable than trying to find the right p/n's and ordering parts. Crimp tools and the like.

Much luck.
Jack Crow aka Radio Mike
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-May-Sat-20-May

Team,
Follow up .

Got the F6 board in the mail this morning.
As mentioned, had to chop a bigger hole in the side of the bot.
Mounted the board, had to make a guess as to which FAN socket to use, so tried FAN1 and it seems to be correct.
Got it printed a test article. So far so good. It's working.

More when I know more.
Jack Crow
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Re: How to verify Transistor is working for Z Sensor

Postby Jack Crow » 2017-May-Sun-07-May

Hi all
Sunday AM
The new board works well.
Again thanks for the insight and support.
Jack Crow
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Re: How to verify Transistor is working for Z Sensor

Postby Mooselake » 2017-May-Sun-09-May

Glad it works. Maybe <ducks> you should move it further from your antenna.

(OT) My net station was connected to a mag mount on a piece of flashing on the desk, shut down my laptop every time I forgot. Finally got an outside base antenna when a new transceiver on the other side of the desk detuned it enough to shut the radio down - took a couple weeks to figure that one out

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