jbc solder station bd-2a repair help - Page 1
Forum section: electronics / repair

author: opethfan
author_rank: Newbie
timestamp: August 28, 2017, 11:41:25 am
content: Hello everyonei 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?

author: voltz
author_rank: Frequent Contributor
timestamp: August 28, 2017, 12:19:48 pm
content: 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..

author: wraper
author_rank: Unknown
timestamp: August 28, 2017, 12:38:34 pm
content: You first should check if triac or whatever pass element used is not shorted. What is actual temperature displayed?

author: opethfan
author_rank: Newbie
timestamp: August 28, 2017, 01:40:45 pm
content: 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...

author: sasa
author_rank: Regular Contributor
timestamp: August 28, 2017, 01:50:30 pm
content: 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.

author: voltz
author_rank: Frequent Contributor
timestamp: August 28, 2017, 02:15:58 pm
content: 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.

author: opethfan
author_rank: Newbie
timestamp: August 28, 2017, 04:01:12 pm
content: 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...

author: Johnny10
author_rank: Frequent Contributor
timestamp: August 28, 2017, 04:10:59 pm
content: Have you written a note to JBC support?

author: opethfan
author_rank: Newbie
timestamp: August 28, 2017, 04:29:30 pm
content: Quote from: Johnny10 on August 28, 2017, 04:10:59 pmyes 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!

author: wraper
author_rank: Unknown
timestamp: August 28, 2017, 04:45:46 pm
content: Quote from: opethfan on August 28, 2017, 04:29:30 pm2 tips wasn't enough to learn a lesson?

author: opethfan
author_rank: Newbie
timestamp: August 28, 2017, 04:52:21 pm
content: Quote from: wraper on August 28, 2017, 04:45:46 pmyou're right but i've done my best to turn off once i see the red

author: wraper
author_rank: Unknown
timestamp: August 28, 2017, 05:09:20 pm
content: What's on the opposite side of the PCB? What if you attach destroyed tip? Does it display temperature?

author: opethfan
author_rank: Newbie
timestamp: August 28, 2017, 05:18:10 pm
content: Quote from: wraper on August 28, 2017, 05:09:20 pm

author: wraper
author_rank: Unknown
timestamp: August 28, 2017, 05:25:41 pm
content: 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

author: sasa
author_rank: Regular Contributor
timestamp: August 28, 2017, 06:03:52 pm
content: 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...

author: wraper
author_rank: Unknown
timestamp: August 28, 2017, 06:11:19 pm
content: Quote from: sasa on August 28, 2017, 06:03:52 pmMicrocontroller has no way to impact anything if power control circuit is faulty. What charge pumping, where do you see such?

author: opethfan
author_rank: Newbie
timestamp: August 29, 2017, 07:22:48 am
content: Quote from: wraper on August 28, 2017, 05:25:41 pm90 k ohm

author: wraper
author_rank: Unknown
timestamp: August 29, 2017, 08:50:09 am
content: 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).