jbc solder station bd-2a repair help

[opethfan]

Hello everyone
i was using my soldering station jbc bd-2a untill it started to burn the tip, with smoke, and the problem is not the handpiaece because i try another working one with same results.
Do anyone have an idea to repair this station?

[voltz]

What temperature do you have the unit set at? It should be around the 350-380 degrees C range. Not over 400!

And tell us if the set temperature is regulating correctly. if you set it to 350, does it stay at 350? or is it getting hotter and hotter..

[wraper]

You first should check if triac or whatever pass element used is not shorted. What is actual temperature displayed?

[opethfan]

the temperature now is setted as 200 degrees but when i turn on the tip turn red-hot and i burnt two of them.
In pratice the temperature control on the board doesn't work.
i attach a picture, if can help to find some component to test...

[sasa]

Can you measure actual temp.  on the tip? With a temp. feature of multimeter, for instance.

Regardless what is display on soldering station, perhaps temp. sensor on the iron is damaged and then it is unable to set proper temp, then actually rise it at  maximum regarding false feedback and then burn the tip.

[voltz]

So, you have 'set'  the temperature to 200c, but once you switch it on it gets red hot. Ok, so what does the display 'read' when its getting hotter? is it rising as expected?

If that is rising high, then it means the thermal sensor is probably fine, it is responding to temperature. So the fault would likely be the triac as mentioned already.
I see no triac device on the PCB.. Is there an external triac connected to the control board? Maybe bolted to the metal case?

If the 'read' temperature is not changing while it heats up, then this is likely a sensor fault in the iron tip. Or the cables / plug from the iron to base.

[opethfan]

i get another similar station from a friend and i tried my handpiece with my iron and it works, so i finally deduced that the problem is coming from the station.

the temperature is set to 200 but i can't wait to read it on the display because when i turn on if i wait the tip will be melt and you know how much it costs...

[Johnny10]

Have you written a note to JBC support?

[opethfan]

Have you written a note to JBC support?

yes i'm waiting their answer, but i think that they will push me to buy a new one... i have burnt 3 tips payed 50 euro for each one!

[wraper]

i have burnt 3 tips payed 50 euro for each one!

2 tips wasn't enough to learn a lesson?

[opethfan]

i have burnt 3 tips payed 50 euro for each one!

2 tips wasn't enough to learn a lesson?

you're right but i've done my best to turn off once i see the red 

[wraper]

What's on the opposite side of the PCB? What if you attach destroyed tip? Does it display temperature?

[opethfan]

What's on the opposite side of the PCB? What if you attach destroyed tip? Does it display temperature?
[/quote

On the opposite side of pcb there is only the lcd panel.
If I attach a destroyed tip it shows "no cartridge" on display like there isn't anything connected

[wraper]

Post a photo of opposite side. I think this mosfet is a pass element but not 100% sure.
http://www.vishay.com/docs/71606/71606.pdf

[sasa]

Something is wrong in software...

This is micro-controller device and it is rather trivial to stop charge pumping if feedback temperature does not change as should be and then return an error...

[wraper]

Something is wrong in software...

This is micro-controller device and it is rather trivial to stop charge pumping if feedback temperature does not change as should be and then return an error...

Microcontroller has no way to impact anything if power control circuit is faulty. What charge pumping, where do you see such?

[opethfan]

Post a photo of opposite side. I think this mosfet is a pass element but not 100% sure.
http://www.vishay.com/docs/71606/71606.pdf

90 k ohm

[wraper]

Then it is not shorted. Probably something wrong in the temperature sensing or circuit driving that mosfet. I personally would attach some dummy load instead of heater in the cartridge so it displays the temperature instead of error. As of the dummy load to use, some powerful resistors of comparable resistance, 24V light bulb, high power 230V halogen bulb or even iron (for clothes).