Ok for those interested. Indeed I ordered myself a dc power supply. Now the thing works flawless. So from the s17 series beyond, you'll need a dc power supply. Original psu won't do it.
Not sure where you bough the tool from, but on Zesbtc they have a huge warning that says:
Notice:
If you test a combined mining machine (a mining machine with its own power supply), you must use the power supply that comes with the mining machine to power the test fixture and the Hash board. It is forbidden to use any third-party or adjustable power supply! Otherwise, it may cause equipment failure!
Source: https://www.zeusbtc.com/ASIC-Miner-Repair/Parts-Tools-Details.asp?ID=212You said you have S17+ which is a "combined mining machine", so you might be careful when using an external PSU, as for instruction, zeusbtc has a truckload of pdf files, search around and you will find the manual for the fixture tool. Good luck