EEVblog Electronics Community Forum

General => General Technical Chat => Topic started by: Balaur on February 28, 2013, 03:48:16 pm

Title: Blatant lack of calibration on Aoyue 936A
Post by: Balaur on February 28, 2013, 03:48:16 pm
Hello all,

The guys from the technical lab recently acquired a 852A++ Rework Station and a 936A Soldering Station.

Upon arrival, they found that the performance of the soldering station was abysmal: the tip was oxidizing instantly and the solder was a rather sad blob of poor looking material. While competent in melting the solder, there was no wetting, no shine, no pleasure to work with.  :-BROKE

Well, we've put that on the poor quality of the delivered tip and we've tried a new original Hakko, with exactly the same behavior.  :-BROKE

After some fiddling, we've found that by setting the temperature to minimum (200C), things were vastly improved, very similar to what you could expect at a normal soldering temperature. Hah! I've constructed a small probe with some thermocouple wire on the tip and guess what?
.
.
.
There was a bloody +150C of difference between the set value and the actual temperature.   :scared:

At the 200C setting, the tip temperature was a rather nice 350C. It was actually easy to fix since the calibration pot is accessible on the front panel by removing a rubber cap. Now everything is OK and the station is actually useful.

(One explanation could be that the factory tried to calibrate the station to 392F but they used a Celsius thermometer.  :-// More likely, no calibration was ever made)

Well, just be aware of this. If you don't have a solder tip thermometer, It's rather easy to use a couple of turns of thermocouple wire on the tip.

BTW, the rework station shown a difference of +30-40C between the set temperature and the measure at 1cm at  the nozzle.
The Weller soldering stations were exemplary: only 2-3 degrees difference.

Best regards,
Dan
Title: Re: Blatant lack of calibration on Aoyue 936A
Post by: c4757p on February 28, 2013, 04:13:24 pm
I have the same model and mine was the other way - it wouldn't melt 63-37 leaded solder unless you turned it to 400. I'd assume that two completely uncalibrated units would at least behave similarly, since the trimpots are usually sold centered - wouldn't surprise me if the factory oompa-loompas just give it a random twiddle with a screwdriver to make it look like they're adjusting it...  ::)
Title: Re: Blatant lack of calibration on Aoyue 936A
Post by: codeboy2k on March 01, 2013, 05:29:16 am
Aoyue 968 hot air station way off by 100's of degrees...

https://www.youtube.com/watch?v=vVL1eDQ7PEY (https://www.youtube.com/watch?v=vVL1eDQ7PEY)


Title: Re: Blatant lack of calibration on Aoyue 936A
Post by: ironcurtain on March 27, 2018, 05:48:27 am
I was calibrating mine tonight and it seems I was not careful enough... the heating element now does not operate. I did manage to get the calibration within 4-5 degrees, but the soldering iron will not heat up anymore. Not sure if it is the ceramic element or something inside the main unit.

Any tips?

PS: This is a 968A