Hello Guest it is August 25, 2019, 07:59:47 AM

Author Topic: ModIO Yaskawa Pendant Project.  (Read 26268 times)

0 Members and 1 Guest are viewing this topic.

Re: ModIO Yaskawa Pendant Project.
« Reply #10 on: February 22, 2011, 09:13:29 AM »
Iaknown,

You most likely blew the small fuse inside the pendant.  Open it up and you will find the fuse in a replaceable fuse holder.  If that fuse is good then you blew the MAX831CWE voltage regulator.  This is a 16-pin surface mount device.  You can actually changes these yourself if you have soldering skills.  The problem is the MAX831 chip has been discontinued so you will have to look for a pin for pin compatible replacement if you determine the fuse is good.  My guess is you blew the fuse.  :)    Hope this helps.

Russ
 ;D

Russ, Thanks so much for the info! This sounds like a start. Unfortunately my fuse is good :-( I had checked it when I took the pendant apart. Now before I go any further, I'd like to make sure I am checking the correct terminals when I say I am getting power. I read 24v between terminals 1 and 7 on the plug, does this sound correct? If so at least something should light up, like the background on the lcd screen right? (it did before at some point). I am good with soldering, just don't know much about circuit boards, so I think I could handle replacing that regulator but have no clue how to find a replacement. First off, what does it look like? Thanks in advance for any help, Dave
Re: ModIO Yaskawa Pendant Project.
« Reply #11 on: February 22, 2011, 09:17:09 AM »
Oh, my board actually looks like the board on the left above, would it still have the same voltage regulator??
Re: ModIO Yaskawa Pendant Project.
« Reply #12 on: February 22, 2011, 10:30:52 AM »

Yes, the picture on the left side is the standard board inside the pendant.  The two screw terminals with the wires coming from the cable should be the 24V inputs.

When you check out the diagram for the MAX831 IC you will note the following information which will help you trouble shoot the pendant.

Voltage Input to the regulator (24V) should be seen on pins 1,2,3,4
Voltage Ouput should be (5VDC) found on pins 13,14,15,16
Ground is on pins 5,7,10,12

MAX831

http://pdf1.alldatasheet.com/datasheet-pdf/view/73816/MAXIM/MAX831CWE.html


I would first check the voltage across the two screw terminals in the pendant and make sure you see the 24VDC.

The check the voltage on the regulator to determine if it is working correctly.  If you see 5V coming out of the regulator you have a bigger problem.

I will see if there is a compatible chip that can be used as a replacement.

Russ
Re: ModIO Yaskawa Pendant Project.
« Reply #13 on: February 22, 2011, 11:45:59 AM »
Oh, the screw terminals?? I thought they were for cable shielding or something the way they went to the cables. I'm not sure I checked them so let me start there. Man I hope it is just an incoming voltage problem, that would be great. Thanks so much, you've been a big help already and I will keep you posted.
Re: ModIO Yaskawa Pendant Project.
« Reply #14 on: February 22, 2011, 12:13:36 PM »
WRONG INFO...

I went down and decided to do some quick testing for you.

The 24V lead coming into the pendant from the cable actually is the WHITE wire connected to PIN#1 of CN4 the white connector.  This actually runs through the on board fuse and then it run to Diode D27 which in turn feeds the MAX831 voltage regulator actually a DC to DC switching regulator to be exact.  The digital ground apparently is the thin BROWN wire which is connected to PIN#4 of the CN4 connector. 

You are correct the two screw terminal are actually the shield on the pendant cable, never really looked that close just saw them next to the voltage regulator and assumed they would be the input lines.  WRONG.  LOL

I tried to find alternates for the MAX831 regulator and no dice.  This unit actually outputs 1A and you can not find anything with this type package and pinout that does the same job.  Actually if you have to replace the regulator because it is not working I would go an alternate route.  If you find it is actually bad you can carefully cut the leads of the device and then use a soldering iron to remove the left over leadwires.  This way you will not destroy the pads on the board.  If you do not have a hot air pump this is the safest method to replace SMT devices.  Now you know the input voltage comes on the left side of the device on pins 1-4, and the output is on the right side of the device on pins 13-16 so you could carefully install a three terminal regulator and then tie the center ground lead with a short wire.  The previous regulator had sense leads and such but you would not really require these are you can get the 5V without that type of regulator.  Just my two cents for a cheap fix.  Verify if you are getting 24V to pin 1 and then to the fuse and then to D27 on both sides.  If you do not see the 24V on the input pins of the MAX831 good chance the diode is bad.  With a few measurements you should be able to pin point the problem pretty quick.

Hope this helps

Russ
Re: ModIO Yaskawa Pendant Project.
« Reply #15 on: February 22, 2011, 12:23:01 PM »
Dave,

Another piece of information.  I discovered the following:

CN4 the white connector the thin BROWN wire is actually tied to the BLACK wire on PIN#7 of the connector and they are both GROUND.  They tied to pins #10 and #15 on the round connector at the end of the pendant cable.  The WHITE wire on PIN#1 (24V) ties directly to PIN#14 in the round connector at the end of the cable.  You can see the numbers if you look in at the end of the round connector the blue plastic has the number embossed.

Let me know what you find out.

Russ
Re: ModIO Yaskawa Pendant Project.
« Reply #16 on: February 22, 2011, 12:40:39 PM »
Crap, I was hoping it was something as easy as input power lacking. I am pretty sure I am getting power and ground to those terminals but let me doublecheck. Thanks again Russ. I will keep you posted.
Re: ModIO Yaskawa Pendant Project.
« Reply #17 on: February 22, 2011, 01:12:41 PM »
Take some quick measurements.

Use the ground pin #4,#7 and put the other end of the meter on the top left of the MAX831 device.  If you look closely at the PCB you will see these leads 1-4 are all tied together so you will not short something out.  You should measure 24V on the left side of the device.  If you get the 24V there then move the probe to the opposite side of the device you can see those top four pins are also connected together 13-16 and you should see 5V.  If you see no voltage on the right side the regulator is dead.  This should be a very quick test.

Russ
Re: ModIO Yaskawa Pendant Project.
« Reply #18 on: February 22, 2011, 01:34:19 PM »
Will do this afternoon, thanks!
Re: ModIO Yaskawa Pendant Project.
« Reply #19 on: February 22, 2011, 03:29:49 PM »
Russ, yup looks like I killed it. There is 24v incoming but only mV on the 5v side. Man, I thought I could solder it no problem but wow those terminals are small! ... not sure if I can swing that.