vin6

in 2010 TSX (without navigation), the radio/climate screen is blank. I followed the Instrument Panel Brightness (p115) in the Owner's manual. Turn the knob on the instrument panel to adjust the brightness with the ignition switch in the ON (II) position and the parking lights on. Still did not turn back the display.

I see for older TSX below solution:
Push and hold the stereo "CD/Aux button" for about five seconds until you hear a beep then release. Your illumination will now be turned back on. You can also repeat the procedure to turn them off again.

Does anyone know of a solution for 2nd gen TSX without navigation?

RTM

I am assuming you don't have a bunch of stuff not working, like your transmission indicator, moonroof switch light, etc, which might indicate a blown fuse (#6, 7.5A under passenger dash) (for a 2012, all I've got)

Having trouble finding the unit in the service manual, more later.

RTM

Looks like the main fuse for the unit is #6, 7.5A under the drivers side dash.

(Damn, there is a whole fancy system to get the HVAC to display its problem, but without the display, you got nothing. Not relevant here, but cool.)

If the climate control display isn't working, here is the clues (2012):
Comm failure between the climate control unit and the HVAC display unit (checks to follow below)

Climate control codes (see parentheses above)
Display dead
Poor or loose connections.

Check for failure:
Unplug display 12Pin connector
w key on, check for voltage between pin 5 and ground (2nd from right, top row, with keys up) - If no, check for Fuse #16, drivers under dash 7.5A, and wire between there and dash

Turn key off
If yes to voltage, pull apart 28Pin connector A, and look for continuity between
28P #19 and 12P #7 (28P bottom row w keys up, 15 is lower left) (12P bottom row keys up #7 if left most) red wire
28P #20 and 12P #8 purple wire

IF no, look for broken wires

IF yes to continuity, check for ground between 28P #19 to ground and #20 to ground separately. - Yes is bad, repair short.

IF no, let us know, check back later, things get uglier, and I don't want to type a long drawn out process if I don't have to. (p21-82)

vin6

Everything is working except the radio/climate screen is blank (but has glow when panel brightness is set high). I guess I must have pressed some button(s) to switch off the display.

RTM

Argh, sorry, been away too long. Glad I left a note where to look in the manual.

Above I noted a 12P connector that you were to pull off and check. Now you need it plugged in, and the jumper pins 7-8 (Red & Purple wires). These are lower left two when looking into the connector, the 1st half size doesn't count.
Turn ignition on. Press and hold the windshield defroster button and on/off button. Is the windshield defroster LED flashing. If yes, the display is bad. IF no, the climate control unit is bad. (Those are some crappy odds.)

Looking at the wiring diagram, there is an illumination circuit feeding the display. Check it at night see if it dims with the switch. IF so, means the display is out, not the back light. Does the clock work, is it in there?

you've got five wires going into that unit,
Lt Grn pin 5 - IG2 (power on), comes on with key, 12V
Red Pin 7 Display - Clock (comes on with IG2)
Purple Pin 8 Display -SI (no idea what it does)
Red pin 10 Illumination - These 2 should change voltage or resistance as you roll the knob
Gray pin 12 Illumi+