This message assumes that the front panel wiring is correct, i.e. pulled from a working system, and you only need to hook up the mainboard correctly. Looking at your pictures, this assumption seems reasonable.

First, get a tool that can do continous real-time processor performance measurement. I recommend landmark V6.0 as included in dosbench. This tool will immediately update when the turbo function toggles. Then, connect the "turbo sw" connector (only 2 of three pins) to the "turbo sw" pin header. It doesn't matter which of the two pins is connected to the black wire. If the turbo button works the opposite way of the way you desire, turn the connector around, so the other outer connector and the black wire are connected to the turbo switch.

Then, after having the turbo switch working, connect the single black wire to one pin of the the "turbo LED" pin header, and check whether the turbo LED responds to the turbo switch. If not, connect the single wire to the other pin, which should provide the correct signal then.

Ok I checked the function of the TURBO button (using NSSI) I can confirm that the button works correctly. However, connecting the single black wire to the Turbo LED does nothing. Just out of interest, I conected the HDD LED to the Turbo LED header on the Motherboard and that too works . So the problem sems to be the digital MHz display (I got the Case from the dump - so I dont know for sure if this was ever working correctly (ias mentioned before it sows a dash - inicating some activity).

Aui wrote on 2025-04-08, 09:38:

(I got the Case from the dump - so I dont know for sure if this was ever working correctly (ias mentioned before it sows a dash - inicating some activity).

Lighting the segments is controlled via the jumpers. The jumpers for each digit are lined up in two possible orientations.

Word of advice, don't leave only one segment on. This board has only one resistor shared for all segments, and assumes a number of segments will be always lit. Leaving only one segment on can cause it to receive too much current by itself and eventually burn. You might notice that the segment is probably too bright or even a little orange.. I suggest jumpering more segments as you begin to adjust the LED to display what you want.

...and once it has been lit for a little while in such state, it probably noticably dims afterwards. I have a few displays that have one segment that is noticably darker than others and most likely from this exact case. It is better to start with all segments on state and then remove stuff as needed rather than other way around.

This message assumes that the front panel wiring is correct i.e. pulled from a working system

Uhh... - the power supply cable was in the completely wrong place, so it would solely power this one particular dash.
Got it fixed now - working all perfectly. Thanks for the help.