Powered by Invision Power Board


Forum Rules Forum Rules (Please read before posting)
Pages:««<4567 ( Go to first unread post ) Reply to this topicStart new topicStart Poll

> Help Repair Treadmill Ps Boards
aevans0001
Posted: November 25, 2010 07:16 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




Ok Jut so you know or remember not sure which, the E1 error comes on because the speed sensor does not detect any movement. I could get the control to stay on and not see E1 by moving the belt myself at that point I could change speed (i think).... But of course the treadmill was not moving it at the time I was..

With good easy instructions I probably could do anything you ask...
PMEmail Poster
Top
ChipUser
Posted: November 25, 2010 05:32 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008




Sometimes my brain only accepts inputs it thinks are necessary for the next step wink.gif I had forgotten about the E1 error message. So if just the movement sensor is the feedback element, you will be able to simulate movement & see what the Gate voltage does.

I am hoping that changing the main (failed) power components does the trick. If it does not & you have to do the circuit tracing, I will say try to collect the data sheets for all the active & passive (except for the resistors, capacitors) components on the board and have them handy. These will help you know (schematically) which pin connects to what and draw it on a paper. I will suggest beginning by drawing the transformer on the left side of the paper and start drawing things from left to right as the pcb traces guide you. label all components clearly. The big chunk of metal between the relay and the fuse is the transformer. Start with 120 volt connections on left (primary) and draw the secondary windings on the right. You can also try using a freeware program like the one below to make things look neat:

http://www.expresspcb.com/expresspcbhtm/download.htm

I started searching for any tools to help someone draw a schematic from a PCB assembly. The only reference I found was to a program named Splan . It seems it allows importing a PCB picture so that one can place the components on a raw schematic and then manually add connections. This is the impression I got. Haven't researched it fully as I don't need it wink.gif If anybody on the forum has experience with Splan, let us know.

PMEmail Poster
Top
aevans0001
Posted: November 25, 2010 07:43 pm
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




Ok removed FET and tested FET still same readings.. 0 on normal test and .01 on the gate.

When the board without the fet is inserted into the treadmill the gate port shows high DC voltage of 114.8 - 114.6.... If motor is plugged in and we are walking on it, this number fluctuates, by the speed of our walking, this does not change by speed controls just by our walking speed. With Motor unplugged number is always 114.6 and does not change with Speed controls..


D5 tests Leg 1 + to Leg 2 - is 3.72
Leg 2 - to Leg 3 + is 3.72
Leg 2 + to anything is open 0
Leg 1 to leg 3 is closed

R27 tests 22 ohmsR24 test 0 on one direction and 12.04 in the other direction.



Why do resistors test differently innstalled? I thought resistors shoudl always measure the same no matter what because that is what they are for?

PMEmail Poster
Top
ChipUser
Posted: November 25, 2010 09:32 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008




The gate voltage changing when you make the motor move is an encouraging sign.

Remember what I said?

QUOTE
Check it to see if it shows like a diode or an open, after the shorted FET is removed. If the diode is open , you will have to get the diode as well. This could be the reason of the FET failure. It appears that the 470K Ohm resistor (R24?) is in parallel with the diode and could affect the diode test. Note that the diode package internally has two diodes in it. They have connected these two in parallel on the board.


When will you learn to refer to the data sheets? doh.gif

A meter reading zero - indicates a short not open. When reading a meter, you are supposed to say what the range is telling you. 3.72 what? Feet, Kg, lb, deg. F?

Resistors read different when installed because things on the board come in series or parallel of their two leads. Read up a little on Ohm's law & series/parallel resistors.

http://en.wikipedia.org/wiki/Resistors_in_parallel#Parallel
PMEmail Poster
Top
aevans0001
Posted: November 26, 2010 07:32 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




QUOTE (ChipUser @ November 25, 2010 09:32 pm)
Remember what I said?

QUOTE
Check it to see if it shows like a diode or an open, after the shorted FET is removed. If the diode is open , you will have to get the diode as well. This could be the reason of the FET failure. It appears that the 470K Ohm resistor (R24?) is in parallel with the diode and could affect the diode test. Note that the diode package internally has two diodes in it. They have connected these two in parallel on the board.


When will you learn to refer to the data sheets? doh.gif

A meter reading zero - indicates a short not open.

I do not understand this portion of your reply...

1. When should I have checked the data sheet? I performed the test you wanted.

2. The 0 was reading without the continuity sound going off so I though that meant it was open, while legs 1 and 3 had continuity which meant closed, and being that having pin 2 is probably the common and not the + that would make the diode read 0 even though it is still open.

3. The only thing I could make out of the whole internal package sentence was that the big diode is actually 2 diodes in one. with legs 1 and 2 and 2 and 3.. 2 being common... I guess this is where I could have looked at data sheet? to determine proper wording?

Thank you for all your help, I just do not know where I went wrong....

Looking for next test?


Edit:

user posted image

I guess I understand sorta... I just always thought that if I tested a resistor inline or out of line across both leads it would read the same, I knew Diodes and other things got skewed inline.

This post has been edited by aevans0001 on November 26, 2010 07:38 am
PMEmail Poster
Top
CWB
Posted: November 26, 2010 02:57 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 21,273
Member No.: 15,154
Joined: May 15, 2008




a semiconductor is not a resistor (per se) .
a little theory will go a long way here :
http://www.radio-electronics.com/info/data...cs-tutorial.php
http://101science.com/transistor.htm (home page : http://101science.com/)

... or ... google "semiconductor theory tutorial" .


--------------------
"Know how to solve every problem that has been solved"
R. Feynman '88
PM
Top
ChipUser
Posted: November 26, 2010 05:12 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008




QUOTE
2. The 0 was reading without the continuity sound going off so I though that meant it was open, while legs 1 and 3 had continuity which meant closed, and being that having pin 2 is probably the common and not the + that would make the diode read 0 even though it is still open.  3. The only thing I could make out of the whole internal package sentence was that the big diode is actually 2 diodes in one. with legs 1 and 2 and 2 and 3.. 2 being common... I guess this is where I could have looked at data sheet? to determine proper wording?


I guess the gist of my post was to get you to start using standard terms to describe what is happening. E.g., the term Closed is used for switches and relays to indicate their state, not to indicate a short (whether by design or fault)

QUOTE
D5 tests Leg 1 + to Leg 2 - is 3.72 Leg 2 - to Leg 3 + is 3.72


When you report meter readings as 3.72 without units, it doesn't help. It could be 3.72 Ohms indicating a practically shorted component, or 3.72 M Ohms telling us that the R24 is bad. With a 470K Ohm resistor in parallel, I would expect a reading of 372K Ohms if the diode is affecting the reading.

QUOTE
Leg 2 + to anything is open 0 Leg 1 to leg 3 is closed


Not knowing the type of meter you are using (feature-wise), the first statement is very confusing with Open & 0 used at the same time. Most DMMs show the first digit as 1 when indicating over-range in the resistance ranges. A meter showing 0 in resistance range means a short (or very low resistance when measuring in higher Ohm ranges).

QUOTE
R27 tests 22 ohmsR24 test 0 on one direction and 12.04 in the other direction.


R27 tests 22 Ohms as you have removed the FET and there is nothing else to affect its reading. If my analysis of the board connections is correct, R24 should read the same as D5 because they are in parallel. Try measuring D5 & R24 in the same meter range.

Does your meter have a diode range (sorry if you already answered this question - when a thread runs in to 3-4 pages, it is difficult to keep track)? If so, lift one leg of R24 and perform diode testing on D5. I think when the board is not connected to anything, that is the only component in parallel with D5. C21 doesn't count resistance wise.

At this point, the only tests I can think of are to ensure D5 is good. After that, we have to wait until you replace the FET and try the board out. If you have spare time on hands and wish to learn more about the circuitry, creating a schematic for the board will definitely help.
PMEmail Poster
Top
tekwiz
Posted: November 26, 2010 06:50 pm
Reply to this postQuote Post


Forum Addict ++
Group Icon

Group: Moderators
Posts: 28,711
Member No.: 5,746
Joined: July 24, 2006




Note that FETs are susceptible to damage from static electricity when out of circuit. A discharge too small to see or feel is more than enough to destroy a FET.
Therefore you should connect yourself to ground while working with or handling FETs. A wire wrapped around a wrist & connected to the ground pin of a receptacle or a metal water pipe is enough. You should include a high value resistor(>100kΩ) in this connection for safety.
Once the FET is correctly installed, the body ground is no longer needed.

Make absolutely certain you remove your body ground connection before plugging the treadmill or any of it's components into the wall.
Being grounded drastically increases your shock hazard when working with mains power.


--------------------
Trouble rather the tiger in his lair, than the sage among his books.
For to you, kings & armies are things mighty & enduring.
To him, mere toys of the moment, to be overturned at the flick of a finger.

Fortuna favet fortibus.
PMEmail Poster
Top
aevans0001
Posted: December 09, 2010 05:01 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




Just to let people know, I am still here and wanting to finish this up. I recieved the FET on Monday and just am way too tired from work to install them...

Is there anything I should test while they are not in again... I know I tested D5, are these tests acceptable or do I need to remove one leg?
PMEmail Poster
Top
ChipUser
Posted: December 10, 2010 04:45 am
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008




I still think that the resistance readings across D5 and the 470K resistor (R24) should be the same as they are in parallel. If they are not the same, try to investigate what is causing it. Other than that, you should be OK to proceed with replacing the FET.
PMEmail Poster
Top
aevans0001
Posted: December 18, 2010 04:28 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




Ok sorry to keep you all on the edge of your seats anxiously waiting on the result of the new fet install...

IT IS WORKING!


Or appears to anyway, I turned it on, and it started moving slowly, so I quickly unplugged it..


Ok Now I just have 1 more question, well maybe more.

Ok reassembly, it has been over a month since I first took this thing apart,a nd I am dumb.

Ok This is the equiptment I have + the board

user posted image

I need to know where the rubber cover goes, does it go on the FET or the DIODE

The inside of the rubber cover has some artic silver on it as does the Diodethe FET looked clean

The little Metal (Heatsink) looks as if it screws into the FET or DIODE and into the metal bracket whichever one does not have the cover on it, and the board slides into the metal bracket. Everything else I can figure out on my own.



As you can see I did label where the wires go...


Here are more pics

user posted image

user posted image

user posted image


PMEmail Poster
Top
aevans0001
Posted: December 18, 2010 04:32 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




Oh yeah also the holes in the metal matches up with FET1 and FET2 or D5 and FET1

I know for certain the rubber cap goes on 1 or the other, I looked at the Data sheet for the fet and I thought it was saying the middle hole was not a ground but I could be wrong

The small holes you see in the first pic next to B and R are the holes that match up with the FET1, FET2, and D5. But only one gets screwed in, as far as I remember.

And what does the Rubber cover really do, and why would it have artic silver in it?
PMEmail Poster
Top
johansen
Posted: December 18, 2010 06:02 am
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 3,128
Member No.: 10,912
Joined: September 06, 2007




two of the three should not have metal exposed on the back of the To-247 package.
so the silicon tube probably goes over the diode.

unless the heatsink runs hot.

let me know if you need some silicon thermal pads, you sure only one had a boot over it?


--------------------
Can the Ethics Committee have a closed door meeting without imploding from cognitive dissonance?
PMEmail PosterUsers Website
Top
ChipUser
Posted: December 18, 2010 06:03 am
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008




I will have to say the heatsink goes on the FET and the rubber goes on the diode. The heatsink looks small though. What is the motor rating again? Does the rating plate say how much current it takes?

The rubber keeps the diode's metal tab from coming in contact with any nearby metal.

I see a big squarish white mark on the big aluminum piece near the labels B & W. The bridge rectifier may have been touching there to use the panel as heatsink. If it does, check the top of the bridge for any continuity to any of the bridge pins. It needs to be completely isolated from the 4 pins. If you have any heatsink compound, use it on the bridge and the FET.
PMEmail Poster
Top
aevans0001
Posted: December 18, 2010 06:12 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




So can someone look at the data sheet and tell me if the round hole in the FET is a ground? It doesn't look like it to me but I dunno...

Here is the link to the Data sheet

Datasheet


Actually upon some research i think I have learned that the FET Drain is also called an OPEN drain which acts like a ground...




PMEmail Poster
Top
johansen
Posted: December 18, 2010 06:34 am
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 3,128
Member No.: 10,912
Joined: September 06, 2007




the IRFP260 may have an isolated mounting hole, but you should see nickel plated copper on the back.

so i'd just use three thermal pads and not worry about it.


--------------------
Can the Ethics Committee have a closed door meeting without imploding from cognitive dissonance?
PMEmail PosterUsers Website
Top
ChipUser
Posted: December 18, 2010 06:36 am
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008




In this case, the Drain is connected to about 200 volts DC. Why are you trying to find if something is ground or not? All electrically live parts need to be isolated from the enclosure. Even when you mount the heatsink on the FET, keep it isolated from the metal enclosure. If the original assembly had the FET bolted to the big panel, they must have used mica or silicon thermal pads and other nylon hardware to keep the FET isolated. Do you remember seeing such hardware?
PMEmail Poster
Top
aevans0001
Posted: December 18, 2010 07:09 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




Well I started lookign around and found the other grey rubber pad... So I put artic silver on FET, Diode, Replicator, then I bolted the piece of the metal to the metal enclosure or bracket using the middle hole. I looke don the grey rubber pads and saw the marking of the metal running across it. The only thing I do not understand is there does not seem to be a "heat sink" Just the rubber pads and then the whole enclosure works as a heat sink? i sitll do not understand how the enclosure woudl work as a heat sink for the FET and then Diode without actually touching them but...

Anyway...

It is working 100% as of now, but w emay need to find out about the heatsink? I tuned it on and adjusted all the speed up and down and the elevation up and down and it all appears to be working... I left it runnign for like 3 minutes.

I do need some lubricant for the belt as this is why the manyfacturer said causes the board to go bad...

PMEmail Poster
Top
CWB
Posted: December 18, 2010 12:25 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Spamminator Taskforce
Posts: 21,273
Member No.: 15,154
Joined: May 15, 2008




the silicone pads are thermally conductive insulators .
these are used to electrically isolate the fet from the heatsink .
there should be hardware that provides a secure mechanical connection of the fet and enclosure .

the type of heatsink compound normally used in these environments is not electrically conductive ...
arctic silver compound is somewhat conductive ... not what i would use for my first choice in this application .
better to be safe than sorry .


--------------------
"Know how to solve every problem that has been solved"
R. Feynman '88
PM
Top
ChipUser
Posted: December 18, 2010 04:39 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008




Get a feel as to how hot the FET gets when you run it for 3 minutes (with load). If it is getting too hot, you need to adjust the way the FET attaches to the case. You can add a measure of safety by adding a small fan to force cool the devices or heatsink. Look for a suitable voltage on the board, something like 12 volts or 5 volts (there may be 78xx type regulators). Then depending on the space available get a small DC fan and mount it strategically.

http://www.goldmine-elec-products.com/depa...s.asp?dept=1043
PMEmail Poster
Top
aevans0001
Posted: December 18, 2010 06:33 pm
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




yeah i once added a fan to my xbox 360 to keep it from overheating all the time... Works good.

Ok so you say get a feel for how hot it gets.... Should I touch the fet? I know you all said that it is very sensitive until it gets connected, is it still sensitive or what?
PMEmail Poster
Top
ChipUser
Posted: December 18, 2010 06:54 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008




Don't worry about the sensitivity aspect now. It is soldered into the circuit (and is working) and you are past the "be careful about . . . ." stage. Just turn off the power before you touch it. That way, even if you accidentally touched the metal tab, you won't get a shock.

If you have a thermometer that goes to about 100 deg. C, try to take a stable reading. The touch technique is OK but won't give a quantitative feedback for us if it is getting hot enough to touch. My earlier question about the motor rating has to do with making a guess at the amount of heat the FET is dissipating when working hard. The more information you provide, better the chance that we can come up with a cooling solution if needed.
PMEmail Poster
Top
aevans0001
Posted: December 29, 2010 07:39 am
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




Ok once again sorry for the long delay. I bought the Treadmill lubricant today and applied. After that I ran it trying to test if the belt was slipping and after aobut 5 minutes the fet blew again? The treadmill went up to full speed, and nothing would stop till unplugged. I otuched the fet and it was very hot, so was the Diode.

The motor rating or all information i can find on the motor is this is the exact info and placement on motor all of it, I do not know what you really need:

DC.PM F001218
Strength Master

Catalog Listing Volts Amp
A1D061 90 17

HP RPM Rotation DUTY FIELD
2.5 4700 CW CONT PM

And a number on the side says 705583

I imagine you were looking for Volts and Amp, or HP and RPM

Let me know, also what type of heatsink compound I should use. Also one of the rubber covers tore on me it is still covering the FET or DIODE but it is torn on back side.

Should I also add the fan? Anyone know where I may want to check for voltages?

___________________________Edit______________________________
Wow that did not come out right... Here it is a little clearer

DC.PM
F001218
Strength Master

Catalog Listing
A1D061

Volts
90

Amp
17

HP
2.5

RPM
4700

Rotation
CW

Duty
COnt

Field
PM

This post has been edited by aevans0001 on December 29, 2010 07:45 am
PMEmail Poster
Top
ChipUser
Posted: December 29, 2010 08:19 pm
Reply to this postQuote Post


Forum Addict ++
*******

Group: Trusted Members
Posts: 2,406
Member No.: 15,445
Joined: May 30, 2008





The motor is rated at 90 volts. What I am wondering about, is why they are using the full 120 volts AC (rectified and filtered) to feed the motor. That brings the supply voltage to about 170 VDC peak (reduced by load). May be they are trying to save money on a transformer. It is possible to use PWM to bring the voltage to the required level, but that also means the FET should never be at a 100% duty cycle.

If for some reason, the PWM part is damaged, The circuit could be feeding voltages higher than 90 VDC to the motor. Let us hope the PWM part of the circuit is still functioning properly.

In that case, let us first focus on heat management. Before I do any calculations, could you post a picture of the way you currently have (or had it when it blew this time) the FET & diode attached to the heatsink/panel? There may be a better way of attaching it. The heatsink compound you want is the non conducting type. Something like this:


http://www.radioshack.com/product/index.js...ductId=2102858#
PMEmail Poster
Top
aevans0001
Posted: January 24, 2011 05:07 pm
Reply to this postQuote Post


Newbie
**

Group: Members+
Posts: 44
Member No.: 33,565
Joined: November 08, 2010




Ok sorry for the long delay, I have been out of town alot lately. But I should be able to give full attenion fo a while now..


user posted image

user posted image

user posted image

user posted image

Ok remember these two things go together by a screw, then the FET and Diode I guess use it through the little rubber piece, I used artic silver on them at the time.

user posted image
PMEmail Poster
Top
0 User(s) are reading this topic (0 Guests and 0 Anonymous Users)
0 Members:

Topic OptionsPages:««<4567 Reply to this topicStart new topicStart Poll

 


:: support us ::




ElectronicsSkin by DutchDork & The-Force