Kaleep (Atten) 8586: iron glowed red and died - precautions with new iron?

[flashjazzcat]

Hi

I'm new to the forum so please bear with me. I did a forum search on the 8586 but was encouraged to start a new topic.

I've had a Kaleep 8586 (2-in-1 soldering/rework) for about three months and I've been very happy with it, but the other night I turned the iron up to 480 to deal with the removal of some stubborn lead-free solder and after I turned the iron down to 400 degrees the tip glowed red hot. I quickly turned off the iron (tip was pretty much toast) and when I turned it on again the heater light soon went out and iron wouldn't heat. The handle was also bent owing to the extreme heat. Ordered an identical replacement (on the assumption the element was burned out) which turned up this morning, but I'm reluctant to test it until I can establish that it's not the base unit itself which killed the iron.

I did a quick cursory inspection of the main PCB and didn't notice any damage, but in another thread regarding a similar problem, there was some suggestion that a triac on the logic board could have failed. I have no objections to performing repair on the mainboard, but I'm not very well versed in diagnostics at this level. Are there any simple checks I can make before testing the new iron? I had initially intended to hook a temperature probe up to the tip and start at around 100 degrees and see if the temps went crazy before gradually ramping things up (I won't be going over 400 again, though!), but if the element burns out again I'm back to square one.

Thanks in advance.

[Armadillo]

There is the other post that advise not to set the temperature above 300 deg.C
And he only ended with adjusting the trimpot. Take a look.

https://www.eevblog.com/forum/repair/atten-8586-tip-is-glowing-red/

Don't plug in. Firstly verify that the live is not shorted to any metal part of the iron by measuring continuity with a multimeter. Verify that earth is connected to the metal part.
Don't plug in the soldering iron.
Verify that the triac is not short-circuited by measuring across the 2 main terminals (The left 2 terminal) of the triac. If shorted, the iron will glow red hot, regardless of your temperature setting.

Re-assemble the unit.

Then;
Turn-on. Set temperature to say 120 deg.C, then turn if off. Plug in the new soldering iron. Turn it on. Quickly use your hand feel the heat and confirm that the iron is heating up.

If not, likely the triac bt137-600E is burned. You will need to open up and change the triac/check it.

Don't set temperature above 300 deg.C. otherwise you will need to calibrate the trimpot and with a Hakko FG100.

[flashjazzcat]

Many thanks for your guidance Armadillo! I will follow those steps carefully and report back with the outcome. Thanks again.

[flashjazzcat]

OK: no short on triac, and grounding appeared OK on the new iron. Started off at 200 degrees with temp probe attached to iron tip, and readings were pretty accurate. Dialled up to 300-400 and temp gauge showed shortfall of some 30-50 degrees. Iron wasn't hot enough to work with until I pushed dial up to 420, checking temps all the time. Wound the calibration pot all the way back and 400 on the dial still equates to an actual temperature of around 360 degrees. Of course my temp gauge may be at fault, but the iron certainly "feels" under-powered at anything under 400-420 on the dial, which equates to a measured temp of 360-370 degrees.

Gonna keep monitoring this carefully before I feel comfortable working with it again.