After bringing my monitor out of standby, I heard a slight pop and then the display faded almost to black, but enough to see the windows as I closed them one by one. The power is working, as the green light is on or blinking. A Dell monitor worked with the computer so I know it's not the computer. I hooked up the monitor to my laptop and set the graphics mode to multiple display, and the laptop desktop screen flashed briefly on the monitor, then went dark. Each time I changed to another setting, I could get a brief image on the monitor. I swapped out the signal cable from the working monitor and tried it with the L170, with the same results as above. When the monitor is not attached to a computer, I get the IBM Thinkvision image, followed by the moving "No connection, check signal cable" message.
None of the monitor buttons, other than the power button, does anything.
I saw reference on this site to a "cable select button" but have no idea where that might be.