Error E11 (broken fan) on ATTEN ST-862D hot air station? - Page 1
Forum section: electronics / general

author: kreyszig
author_rank: Regular Contributor
timestamp: November 30, 2023, 03:43:37 am
content: Hi,I tried turning on my ST-862D station tonight and I got an E11 (broken fan) error. I think it might be the 6th time I use it and it was working perfectly before. I looked at the fan and it does at least turn freely. Also I looked at the transformer and the 24 V output looks ok. It does not seem to be a very common error based on googling it. Do you think it is likely to be a defective fan motor? Has the fan some kind of 24V 4-wire PWM pin out?Thanks!

author: thm_w
author_rank: Super Contributor
timestamp: November 30, 2023, 10:27:52 pm
content: The fan is 4 wire as seen here (and as you would have seen when you took it apart?):https://m.media-amazon.com/images/I/61w2d3ujbmL._AC_SL1000_.jpghttps://twitter.com/Phoebe94572967/status/1586912061858402306So probably the tach output is broken or the fan itself is broken.Maybe try to power the fan with an external supply to test it. But figure out the pinout first, it may be red and black or yellow and black... and if pwm signal is active high or low.https://aliexpress.com/item/1005006045889260.html

author: kreyszig
author_rank: Regular Contributor
timestamp: December 01, 2023, 01:31:52 am
content: Quote from: thm_w on November 30, 2023, 10:27:52 pm.Yes, it is how it looked like (alsohttps://www.aliexpress.com/item/1005006045889260.html?src=google&aff_fcid=438644e386184d30aeae3d637fcc6b03-1701315578772-09259-UneMJZVf&aff_fsk=UneMJZVf&aff_platform=aaf&sk=UneMJZVf&aff_trace_key=438644e386184d30aeae3d637fcc6b03-1701315578772-09259-UneMJZVf&terminal_id=12702cff63f74a97861b1f6968b5fa7a&afSmartRedirect=y). I will do some tests as you suggested. Thanks!

author: kreyszig
author_rank: Regular Contributor
timestamp: December 01, 2023, 03:35:15 pm
content: Quote from: kreyszig on December 01, 2023, 01:31:52 amOk so the red wire is supplied +24V DC relative to the black wire, and it does not seem to change regardless of what I do when the unit is on. When I probe de blue wire, it seems to be at 0V regardless of what I do. When I probe the yellow wire, it seems to increase to a fraction of a volt when I push the button on the handle to activate the hot air. So my guess would be that the yellow wire would be the PWM signal, but there is something broken on the board which prevents the PWM signal to be generated properly? Unless there is a short for the PWM line on the fan which pulls down the PWM signal from the board?When everything is off, the resistance between the yellow and black wire is infinite. When the unit is powered, this resistance falls to 0. When I push the button on the handle to turn on the fan, the resistance becomes infinite again. What I would conclude from this is that the main board is defective. What do you think? Thanks

author: thm_w
author_rank: Super Contributor
timestamp: December 01, 2023, 11:09:00 pm
content: If the main board is defective then you should be able to unplug the fan and run it from an external supply.The only issue is I don't know what PWM signal its expecting. Usually you can pull the PWM signal to ground or to 24V with a 10k resistor, but some might want 5V.The PWM input is usually blue color.

author: kreyszig
author_rank: Regular Contributor
timestamp: December 02, 2023, 04:05:19 pm
content: Thanks. If the main board is defective I should return the whole unit for repair under warranty. The fan connector is glued, so I prefer to not mess with it. If it was just the fan it would be probably better for me to just order the fan as it would not be worth paying for shipping of the whole unit...