What Are These Resistor Looking Componenets?

[jostewcrew]

Re: What Are These Resistor Looking Componenets?

Is one end of these two resistors have one end connected to Source and another connected to the Negative leg of the main filter cap?
What is connected to the drain of the MOSFET, I see the terminal next to it with (+) label.
The large Wattage of the resistors of the resistors are to big to be used to protect IC that draws so little current, it would be 1/4 W or so of fusiible resistor for protecting the IC.

If you can read the part number of the IC that drives the Gate of the MOSFET then you can look up spec sheet and may be application circuit for the IC.

both resistors are connected to the source of each mosfet.

the + is output 1 from the transformer, connected to the gate of the mosfet that blew, then through a diode to the resistor that looked burnt but still reads within the tolerance found from my searching earlier. diode is still good as well. im thinking that it was just a bad fet.

the main cap that blew traces as a part of the output 2 from the transformer. (anode side) this is why i was initially thinking that the transformer went bad.

ive been searching for a spec sheet on the ic, naturally as its on a circuit path in a sense of a circuit that went south, but have yet to find what im looking for.

[budm]

Re: What Are These Resistor Looking Componenets?

Can I see how the other stuff are connected to this board?

Does it use DC motor?

I also did not realize that there are two MOSFET's, is that right?
https://www.badcaps.net/forum/attach...7&d=1597699047

[jostewcrew]

Re: What Are These Resistor Looking Componenets?

Can I see how the other stuff are connected to this board?

Does it use DC motor?

I also did not realize that there are two MOSFET's, is that right?
https://www.badcaps.net/forum/attach...7&d=1597699047

yes 2 fets.

sure, any pointers on how you want, what you want to see uploaded? its ac in, converts to dc, and pushes a dc servo motor for a hydraulic lift. up and down functionality.

let me know exactly how you want to see and what, video, pics...ill upload tomorrow.

[budm]

Re: What Are These Resistor Looking Componenets?

yes 2 fets.

sure, any pointers on how you want, what you want to see uploaded? its ac in, converts to dc, and pushes a dc servo motor for a hydraulic lift. up and down functionality.

let me know exactly how you want to see and what, video, pics...ill upload tomorrow.

After seeing the second MOSFET I'm beginning to think it is using Half H-Bridge motor drive and using relay to change direction of the motor.
And to prevent the circuit from overload due to mechanical binding or motor stall, they sense the over current through the resistor to shut down or stop the drive to the MOSFET, I am sure they have to have some sort of protection against stall or binding some how, that is my theory.

I like to see what kind of Transformer that you mention and see if the motor is connected to the drive circuit through relay contacts of the board or not.

Right now it is just my curiosity as to what topology they are using on this board.

It see that there are still lots of company still selling motorize TV Lift.

[redwire]

Re: What Are These Resistor Looking Componenets?

I think it controls two motors (with relay H-bridge) and a mosfet for the final switch. So two relays+mosfet per motor. It monitors their current to protect against jams or maybe uses that for limit sensing.
It takes a while to heat up and cook a power resistor, so that would imply a shorted mosfet or the over-current did not properly trip.

I would check that none of the relays are stuck with welded contacts. The mosfet should be doing the final switch on/off if it is N-ch in the return path to PSU GND.

[jostewcrew]

Re: What Are These Resistor Looking Componenets?

After seeing the second MOSFET I'm beginning to think it is using Half H-Bridge motor drive and using relay to change direction of the motor.
And to prevent the circuit from overload due to mechanical binding or motor stall, they sense the over current through the resistor to shut down or stop the drive to the MOSFET, I am sure they have to have some sort of protection against stall or binding some how, that is my theory.

I like to see what kind of Transformer that you mention and see if the motor is connected to the drive circuit through relay contacts of the board or not.

Right now it is just my curiosity as to what topology they are using on this board.

It see that there are still lots of company still selling motorize TV Lift.

i thought that perhaps the motor seized as well. Havent been able to test yet but will be applying direct current to the motor once i recieve my male adapter and mak a pig tail for my dc power supply. its a 6 pin s plug from the motor to the control box, h,n,g for up and h,n,g for down im assuming.

the out put 1 from trans goes to the plus on the board that the mosfet blew. The output 2 seems to trace to the big cap that blew on the anode side. there are to white wires that insert via connector, im assuming this is the current sensing for the trans.

there is also a type of small current transformer that a wire feeds through the center and solders to the board. this sits above the two white wires from transformer on the board.

there is only one motor that supplies both the up and down function for the lift.

there are other companies with proprietary lift systems and controllers that would need to be retrofitted into the cabinet. they dont sell just a controller that is compatible. ive reached out to many companies to see. This particular company is kaput.

[budm]

Re: What Are These Resistor Looking Componenets?

https://www.badcaps.net/forum/attach...0&d=1597840134
That big transformer looks like TOROID power transformer.
What does it show on the motor label?
Very interesting setup. I see some of these Lift systems sell for over $500.

[jostewcrew]

Re: What Are These Resistor Looking Componenets?

yeah its a toroidal... tto-12493-01... got 3 fuses. my parts arrive today. gonna fit components tomorrow, ohm out for any shorts again to be safe before applying transformer, check for shorts again, then apply power to the controller. if it holds, im going to move on to checking out the motor itself. make sure it isnt seized up. if it is, ill remove the fluid and see if i can free it up. if its good, ill just hook everything up and see whats what.

i dont have the motor here with me, just the controller.

ill post after its all done for update.

[budm]

Re: What Are These Resistor Looking Componenets?

Wishing you luck, hopefully it is the motor fault not the board fault, motor you can repaired but trying to repair the board is more difficult since you do not have the schematic.

[jostewcrew]

Re: What Are These Resistor Looking Componenets?

Replaced the fet and the cap. controller works. depending on how this controller is set up, i believe the cause was a bad relay. the up function clicks when pressed but nothing on the down. the controller is powered and holding however.

so, either this means a bad relay of sorts, that possibly shorted out the circuit while it died and now has no affect as it still holds current fine,

or,

the controller recognizes a memory setting of sorts that only goes down after fully locking out in the up position? this doesnt really make sense to me, but just putting that out there.

i tested all relays against eachother before while troubleshooting the board and nothing rang out or showed shorted to ground. i believe if it was the relay, it would have blown the circuit again?

[R_J]

Re: What Are These Resistor Looking Componenets?

Usually when you run a motor to drive a mechanical actuator it will have limit switches somewhere to stop the motor from over driving the actuator. Sometimes these switches also have a diode across them so when the switch is activated (opens), the motor then stops, but when the motor voltage is reversed to change the direction of the actuator the current flows through the diode alowing the motor to run inthe reverse direction.

[jostewcrew]

Re: What Are These Resistor Looking Componenets?

Usually when you run a motor to drive a mechanical actuator it will have limit switches somewhere to stop the motor from over driving the actuator. Sometimes these switches also have a diode across them so when the switch is activated (opens), the motor then stops, but when the motor voltage is reversed to change the direction of the actuator the current flows through the diode alowing the motor to run inthe reverse direction.

perfect.. that explains the non function for now. i will hook it up to the motor and see what happens. if it blows at that point, i know its the motor itself and can move forward. if it doesnt, then ill chalk it up to the bad components. if it still doesnt move down after moving up, ill swap the relay and double check the diodes in that circuit. as for now, it seems fine.

[redwire]

Re: What Are These Resistor Looking Componenets?

It's strange- the board supports two motors.
I sketched the relay/mosfet portion of the schematic, but not sure what the two DIN connectors are for. Hard to see limit switch inputs.
I would also ensure the +5V rail is good.

[jostewcrew]

Re: What Are These Resistor Looking Componenets?

It's strange- the board supports two motors.
I sketched the relay/mosfet portion of the schematic, but not sure what the two DIN connectors are for. Hard to see limit switch inputs.
I would also ensure the +5V rail is good.

i will look into a second motor in the cabinet, but i only saw one when i did my initial inspection. im going monday to fit and test the progress so far. until then, nothing really more i can do.

thank you all for the input thus far, i will update on moday.

[jostewcrew]

Re: What Are These Resistor Looking Componenets?

update:

double checked the motor. there is only one, central, raising and lowering the tv mount from cabinet. motor was not seized up from my checking.

plugged everything up and worked like a charm. the n channel mosfet and the main cap was the only things blown and replaced. ill chalk it up to old age.

[budm]

Re: What Are These Resistor Looking Componenets?

Thanks for the follow up.
So what is the rating of the motor?