How to repair 8586 station.
First moment - check, that all pins on the heater gun's connectors are on their positions - some pins could fall into the connector.
So, if, for example, temperature sensors connector fell into the connector, you will see S-E on the display. This station could be based on MCU s3f94c4ezz-dk94 Zilog architecture, produced by Samsung. I found programmer for such MCUs here -
https://www.vipprogrammer.com/quick-samsung-mcu-programmer-qsp12-usb-universal-programmer-programmer-2937 . Datasheet is here - PS0315.pdf . You can buy s3f94c4ezz-dk94 MCU here. Software to programm this MCU POSSIBLE could be found here - http://www.cnatech.com/download.htm . Heater driver of the device could be based on BTA16-600B triac. You can buy
BTA16-600B triacs here. Datasheet for BTA16-600B triac - haopinfsj489ydf945dt.pdf The basic scheme to test triac: One guy made schematics for his 856D soldering station, it could be useful for rev. eng. of my 8586 soldering station -
858D_RevEng_Schematic.pdf . Source - http://www.heartoftechnology.com/reverse-engineering-the-858d-hot-air-rework-station/ My station has also BT136-600E triac - I still have not figured out, for what. Datasheet for BT136-600E -
BT136-600E-352978.pdf 8586 ready to use PCBs could be found here -
http://s.click.aliexpress.com/e/e2BU3JI and here https://ru.aliexpress.com/item/1PCS-High-Quality-Motherboard-PCB-for-Eruntop-8586-Soldering-Station/32831587903.html This station is also has 3041 (aka MOC3041) chip - Triac Driver Output Optocoupler. First datasheet -
MOC3043M-D.pdf , second datasheet: MOC3042.pdf . Could be found here http://s.click.aliexpress.com/e/EqBEyFa , direct link to the product sample with good price: http://s.click.aliexpress.com/e/rB2JA6m .