SOLVED - Turbo Duo thinks it´s aways closed - Laserunit does nothing

[thesteve]

ok that looks good, do the same on IC501

[Xenogears]

Old Post - new Answer: SOLVED. Damn. All the measuring for not finding a tiny solder-bridge on Resistor Array (RA512) 

After finding that out, the Lid-Detector-Switch was recognized again.

"Please close Cover"

I did not work on the PCB for a very long time - Sometimes time is the key :-)

[crossmanbx]

I have sometimes the same issue, i'm going to have a look for  RA512 too. Thank you for your answer !

[soop]

So glad you managed to solve it, after over a year!  And props for coming back to document the answer, very cool.

[Xenogears]

The Point is  not only to look for the Resistor Array. Please frist always check the VIA. If they have connectivity, go on, trace connectivity from Pin to Pin