"Bump"
any alternatives. Can any one host it as a winrar file

I split it into two binders. Here they are. You can use Acrobat to re-combine, if you need to. The split is at page 50.

John
View attachment 23803

View attachment 23804

 

Hey....John..
U are like sooooooooooooo yesterday.

I got it.
Thanks anyways.

By the way..Do u know how to check an SCR using a diode check mode

 

First off.....SportsArt ones is on hold till I get the parts from mouser.

For now cybex one is going on.

After the first attempt I installed the board to a working one and at in instant it gave me error 1.
error ones tell to check the SCR, Motor feed back and lower board ( this PCB).
Since I checked the SCR and the tacho is mounted on the motor and is working, problem still is in the lower board.

So after replacing the opto, diodes and R, clean up. I tested and got the same error but this time the tread tried to start. Before it did not. Which tells me there still is another issue associated with previous fault.

I checked the transistor and the SMD 339's in the motor PWM. Found nothing wrong but what I noticed is lower B+ for the motor.
55V.

Circuit tracing shows two power relays are in series with the Mains and bridge of the HVDC, That area has been tampered before by other parties..
so I took them all out, cleaned and found the via holes broken. So thinking this could be a reason I soldered them back properly from both sides.
Gave power and one relay clicks...B+ rises to 124VDC.....
not enuf, I think.
One relay is for the emegency stop and the other relay is for tht motor PWM B+.
The other relay does not, but when I forced it on B+ rises to the correct value which is around 300vDC.
So what I think is there is a fault in the drivers.
So checked and found SMD transistor.One open, one short, noway of figuring the number. Getting a schema is impossible. Only is to reverse engineer it.
So below the driver ckt

This is the circuit layout. The relays are 24 V power relays.
One control the emergency stop and other is in series with the main bridge.
From console connector is the line which connect to the top control panel.
Q1 works and is labeled as such for clarification.
I am having trouble finding out the two relay drivers.Q2 and Q3
since they are faulty. I donno if they are NPN or PNP or a NPN and a PNP.
Ckt is exactly how they are connected. Diagram shows NPN but it is just to show u guys.

Fellas, please tell me what will be the Tr type based on the circuit and my explanation.
Thank a bunch

{ed}
what I think is one shud PNP and other one NPN..right?

 

Q1's base circuit doesn't make sense unless the undocumented side of the safety switch comes from 18v.

I'm not keen on the way Q2 and Q3 have been used as voltage followers; that would result in some heating.
What current/voltage do the relay coils require for pull-in and dropout?

 

Using PNP's instead would make the transistors into switches with the relay in the collector leg. A more likely scenario

 

Q1's base circuit doesn't make sense unless the undocumented side of the safety switch comes from 18v.

The console is supplied with 18V. I have tested this board on a working cybex tread. So the fault lies with in this circuit.

I'm not keen on the way Q2 and Q3 have been used as voltage followers; that would result in some heating.
What current/voltage do the relay coils require for pull-in and dropout?

Relay coils Voltage is rated 24V. The Vcc for the circuit is derived from a transformer and is 18V. When I short the CE of both, the relays works.

What I like to know is when Q1 switches does the relay switches alternately. I mean one is for emergency cuttoff.

I think I need to draw more of the board to be sure of anything.
Working on the diagram. Pls do check later

 

OK guys...here's what I can make of it.

They shud be PNP.

Why?

Because if the console is disconnected the relay won't switch. Safety feature..no?
No console Shuts down high voltages. Which will obviously shut down all the motors
If the console is connected and powered, the console will switch on Q1 by which Q2 & Q3 will energies the relays powering the PWM and the Incline circuitry

Correct?

 

It's been a long time. The components I ordered ended up in US post office. My Christmas gift never made it to the plane....

Oh well !! **** happens.

Anyways, I have been at it every now and then, it's really hard with all the supervision and all.. Since the components is having a hard time arriving here I worked on the cybex PCB.

The schematic I talked about helped a lot. I managed to find two SMD transistors that can handle the relays. The area I was talking about is shown below.

The doodle brains who tried to fix it cannot seem to find that simple fault, instead they managed to destroy the board by pulling out power components, and when they did they pulled the vias too. Which is the things that gave me the runaround.

A spark here and crack there seems to be the problems. I tested this board with an another identical cybex. The first power up gave me a "BANG". I was happy that atleast the board replied to me. .

After a few days the board worked flawlessly. Which means my assumption on the PNP's was right.

After the Lower board came another problem. The carbon brushes needs to be replaced, as I have swapped the brushes from this tread to the working one when it started to give "brush error".

The Guys who sell them brushes charges $57.00 per piece and these things are huge. Problem is one has a sensor wire

Getting the brushes was an impossible task since rm can't seem to sent me the components which I have bought for the SportsArts one ( due to heavy snow ), and the customer is getting cranky. Maldivians act really weird when it comes to things like this. Sometimes they tend call you names and in their heart (it's theft ). It's in there nature, cause it's what they always think about, that someone will always rob you. They can't seem to think on the positive side of things.
What they don't understand is to trust someone who really knows what he does but instead they tend to believe in those who brags all the time.

Sadly, it came to this that they even tried to take away the two PCB's from me and give it to some other wannabe to fix it. after all what they went through they never realize they are going to end up in square one again. They know that I have fixed one PCB atleast and due to delay in components for the SportsArt they thought of ditching me. The Nerve of them. It was in their mind that I have gobbled up the advance money they gave me to order for the components. I couldn't believe what I was hearing, I can see it in their face. I know why this happens. If I say it, it won't be good. I know someday they will see this thread, and I couldn't care less. I just like to share my work to you guys even though everyone can see this. This way I can say that I have nothing to hide and I am not the common type that dwells here.

So after a lotta phone calls I managed to convince them to let me find the brushes. I wanted them to see what it is like to find something that is hard to find and they ended up in paying advance to those who originally sold the treads to them. This was when this job started, I told them that I would need the brush to finish it. Even they can't seem to find the brushes for these motors to this day and these guys have a huge billboard saying Service Center. The F*****g lot. All these places are shown to people to make them believe something that is not and to hide what they actually do. It's a front of some kind, it always is.

Sorry abt tht...so..I managed to find an oversize brush from a friend. I know I can file them down to size but what about the sensor wire in one of 'em brushes.

Well, believe it or not I have made the sensor wire exactly how it is in the original one. See below.

 

Not bad huh!!. I filed the over sized brushes and made a sensor and now I know the trick those guys uses to sell their unique brushes. It's all about selling stuff .

Now I can get the same brush for half the price here.

The Motor runs smoothly and the board is fixed and tomorrow I will try to set the tread up for a test run.

Stay tuned for the update.

 

Ok...this thing is showing error after error. No same error twice.
So brought back the console for further study. Funny thing is now it runs flawlessly.

See the video

 

Well ! after a long brain storming I managed to pin point the erratic errors..

It was just loose lug connects.

Now the Cybex is up and running.

Before there was one, now there is two

{ed}
Hey....I am in the pic. see the mirror.

retched buddy...where are you?

 

This thing again started to act up.
Error 1 and sometimes error 6.

The Bloody thing seems to work when I am at the gym but refuses to start up for a customer.

Am cracking the board again..

 

Maybe it doesn't mind being used by you. Ya know, someone who only weighs 140 pounds.

But when a big-mama 300 pounder jumps on it, it says "Forget this, Im going to sleep"

 

Maybe it doesn't mind being used by you. Ya know, someone who only weighs 140 pounds.

But when a big-mama 300 pounder jumps on it, it says "Forget this, Im going to sleep"

So it seems...........

 

U know what.....the bloody MOSFET's blew. And these buggers are @500V @20A.

I'm trying to reverse engineer the PCB to find the possible faults.

I think I am Getting the hang on the error codes. How and why an error shows is now surfacing.

Found two Filter caps leaky.

The Motor voltage does not switch on if the motor is not there. Meaning that in order for SCR to fire, motor should be connected.
This was something I have had trouble with, since I have drawn the circuit, things are starting to make sense.

I checked the board at the bench with dummy loads and dummy inputs.
I can switch on the relays thus giving power to the board. My check result in getting 300VDC at the motor output.
And it Varies as I vary the dummy speed signal. I know it too high, cause it should be 200VDC.

I wanted to check it in the tread. So, later tonight I went and mount the board and started and freaking thing gave an error 6. Which is over speed.

Well !! DUH!!!....300VDC will overdrive the motor instead of 200VDC.
Without the motor the Motor B+ Voltage will not rise. Once the motor is connected it slowly rises to 300VDC.

One problem the cathode of SCR gives me 200VDC but the Anode is giving me 300VDC. . The SCR fires charging the caps. And it is charging to 300V instead of 200V.

What gives

 

I checked the board at the bench with dummy loads and dummy inputs.

Lets see...

Dummy Loads... CHECK!
Dummy Inputs... CHECK!
How about the tech?
....CHECK!


HAHAHAHA

oh, geeez..ok.

Are you saying the mosfets are cooking without the motor being installed?

 

Na Na Na Na!

Now nothing cooks. Now I get over speed error...the reason what I think for this problem is now the motor gets 300VDC instead of 200VDC.

The SCR is firing but what I cannot figure out is why the anode has 200VDC and cathode is at 300VDC

 

The SCR is firing but what I cannot figure out is why the anode has 220VDC and cathode is at 300VDC

WOAH!

Thats not right!

Or is it... Does the biasing have anything to do with the firing angle?

 

Aaaaaaaaaaargh!! Had to check the SCR firing Circuit...

The tread is over-speeding indeed. Oh well!! at least I managed to fix the starting issue., which was error 1...

 

This is crazy. Why does everything ends up in my hand when we have so many authorized professionals.

Oh well!!
One Tread is in operation since I had swapped the brushes.
So Now I have started my work on the SportsArt tread PCB.

Took out all the Power components and cleaned the nice soldering previously done.
I'll Just show u the works

The IGBT's are shorted. The power diodes are OK but due to fine handling the pins are bend and twisted....so I don't think I wud be using any of these components.

I have only one component.
The IRFP460. This was bought during a repair attempt few years back.
Other components are available at digikey and I hope My good friend is there to get 'em for me when the time comes.

Besides having the IGBT's shorted I cud not find any other faulty component and was wondering why the heck, who ever they are did what they had done to this board.

I mean why try to desolder all the power components including the bridge and after all their both hand wanking cud not get this thing done.

They might have bought new components from Male' ( I will not trust them cheap Chinese parts) or cud have got from abroad.

But the real problem is wht the heck was it fritz to this day.
My careful eye poking found me this

see the circle, the opto had solder jumper. At first I though it was nothing but I cannot flick it out. so tested the Pins with the meter and Viola!!
The bloody opto was shorted. And the solder not a drip but a real hot drip onto the pins.

Alas !!!! we have all the wannabees.

Hello,
Do you happen to remember what the original IGBTs model number were?