Lost keyboard keycodes.

Question

Some hours ago I tried to lower the volume with the keyboards dedicated key. It didn't work. I was working seconds ago.
I tried xbindkeys -k:
Press combination of keys or/and click under the window.
You can use one of the two lines after "NoCommand"
in $HOME/.xbindkeysrc to bind a key.
"(Scheme function)"
m:0x0 + c:176
NoSymbol
It used to be FX86AudioRaiseVolume.
Actually all multimedia keys stopped working. Every one produces NoSymbol.
xmodmap -pke
keycode 8 = Mode_switch NoSymbol Mode_switch
keycode 9 = Escape NoSymbol Escape
keycode 10 = 1 exclam 1 exclam
keycode 11 = 2 at 2 at
keycode 12 = 3 numbersign 3 numbersign sterling
keycode 13 = 4 dollar 4 dollar
keycode 14 = 5 percent 5 percent EuroSign
keycode 15 = 6 asciicircum 6 asciicircum
keycode 16 = 7 ampersand 7 ampersand
keycode 17 = 8 asterisk 8 asterisk
keycode 18 = 9 parenleft 9 parenleft
keycode 19 = 0 parenright 0 parenright degree
keycode 20 = minus underscore minus underscore plusminus
keycode 21 = equal plus equal plus
keycode 22 = BackSpace BackSpace BackSpace BackSpace NoSymbol NoSymbol Terminate_Server NoSymbol NoSymbol Terminate_Server
keycode 23 = Tab ISO_Left_Tab Tab ISO_Left_Tab
keycode 24 = q Q semicolon colon periodcentered
keycode 25 = w W Greek_finalsmallsigma Greek_SIGMA
keycode 26 = e E Greek_epsilon Greek_EPSILON EuroSign
keycode 27 = r R Greek_rho Greek_RHO registered
keycode 28 = t T Greek_tau Greek_TAU
keycode 29 = y Y Greek_upsilon Greek_UPSILON
keycode 30 = u U Greek_theta Greek_THETA
keycode 31 = i I Greek_iota Greek_IOTA
keycode 32 = o O Greek_omicron Greek_OMICRON
keycode 33 = p P Greek_pi Greek_PI
keycode 34 = bracketleft braceleft bracketleft braceleft
keycode 35 = bracketright braceright bracketright braceright
keycode 36 = Return NoSymbol Return
keycode 37 = Control_L NoSymbol Control_L
keycode 38 = a A Greek_alpha Greek_ALPHA
keycode 39 = s S Greek_sigma Greek_SIGMA
keycode 40 = d D Greek_delta Greek_DELTA
keycode 41 = f F Greek_phi Greek_PHI
keycode 42 = g G Greek_gamma Greek_GAMMA
keycode 43 = h H Greek_eta Greek_ETA
keycode 44 = j J Greek_xi Greek_XI
keycode 45 = k K Greek_kappa Greek_KAPPA
keycode 46 = l L Greek_lamda Greek_LAMDA
keycode 47 = semicolon colon dead_acute dead_diaeresis
keycode 48 = apostrophe quotedbl apostrophe quotedbl
keycode 49 = grave asciitilde grave asciitilde
keycode 50 = Shift_L ISO_Next_Group Shift_L ISO_Next_Group
keycode 51 = backslash bar backslash bar
keycode 52 = z Z Greek_zeta Greek_ZETA
keycode 53 = x X Greek_chi Greek_CHI
keycode 54 = c C Greek_psi Greek_PSI copyright
keycode 55 = v V Greek_omega Greek_OMEGA
keycode 56 = b B Greek_beta Greek_BETA
keycode 57 = n N Greek_nu Greek_NU
keycode 58 = m M Greek_mu Greek_MU
keycode 59 = comma less comma less guillemotleft
keycode 60 = period greater period greater guillemotright
keycode 61 = slash question slash question
keycode 62 = Shift_R ISO_Next_Group Shift_R ISO_Next_Group
keycode 63 = KP_Multiply KP_Multiply KP_Multiply KP_Multiply KP_Multiply KP_Multiply XF86ClearGrab KP_Multiply KP_Multiply XF86ClearGrab
keycode 64 = Alt_L ISO_Next_Group Alt_L ISO_Next_Group
keycode 65 = space NoSymbol space
keycode 66 = Caps_Lock NoSymbol Caps_Lock
keycode 67 = F1 F1 F1 F1 F1 F1 XF86Switch_VT_1 F1 F1 XF86Switch_VT_1
keycode 68 = F2 F2 F2 F2 F2 F2 XF86Switch_VT_2 F2 F2 XF86Switch_VT_2
keycode 69 = F3 F3 F3 F3 F3 F3 XF86Switch_VT_3 F3 F3 XF86Switch_VT_3
keycode 70 = F4 F4 F4 F4 F4 F4 XF86Switch_VT_4 F4 F4 XF86Switch_VT_4
keycode 71 = F5 F5 F5 F5 F5 F5 XF86Switch_VT_5 F5 F5 XF86Switch_VT_5
keycode 72 = F6 F6 F6 F6 F6 F6 XF86Switch_VT_6 F6 F6 XF86Switch_VT_6
keycode 73 = F7 F7 F7 F7 F7 F7 XF86Switch_VT_7 F7 F7 XF86Switch_VT_7
keycode 74 = F8 F8 F8 F8 F8 F8 XF86Switch_VT_8 F8 F8 XF86Switch_VT_8
keycode 75 = F9 F9 F9 F9 F9 F9 XF86Switch_VT_9 F9 F9 XF86Switch_VT_9
keycode 76 = F10 F10 F10 F10 F10 F10 XF86Switch_VT_10 F10 F10 XF86Switch_VT_10
keycode 77 = Num_Lock NoSymbol Num_Lock
keycode 78 = Scroll_Lock NoSymbol Scroll_Lock
keycode 79 = KP_Home KP_7 KP_Home KP_7
keycode 80 = KP_Up KP_8 KP_Up KP_8
keycode 81 = KP_Prior KP_9 KP_Prior KP_9
keycode 82 = KP_Subtract KP_Subtract KP_Subtract KP_Subtract KP_Subtract KP_Subtract XF86Prev_VMode KP_Subtract KP_Subtract XF86Prev_VMode
keycode 83 = KP_Left KP_4 KP_Left KP_4
keycode 84 = KP_Begin KP_5 KP_Begin KP_5
keycode 85 = KP_Right KP_6 KP_Right KP_6
keycode 86 = KP_Add KP_Add KP_Add KP_Add KP_Add KP_Add XF86Next_VMode KP_Add KP_Add XF86Next_VMode
keycode 87 = KP_End KP_1 KP_End KP_1
keycode 88 = KP_Down KP_2 KP_Down KP_2
keycode 89 = KP_Next KP_3 KP_Next KP_3
keycode 90 = KP_Insert KP_0 KP_Insert KP_0
keycode 91 = KP_Delete KP_Decimal KP_Delete KP_Separator
keycode 92 =
keycode 93 =
keycode 94 = less greater guillemotleft guillemotright bar brokenbar
keycode 95 = F11 F11 F11 F11 F11 F11 XF86Switch_VT_11 F11 F11 XF86Switch_VT_11
keycode 96 = F12 F12 F12 F12 F12 F12 XF86Switch_VT_12 F12 F12 XF86Switch_VT_12
keycode 97 = Home NoSymbol Home
keycode 98 = Up NoSymbol Up
keycode 99 = Prior NoSymbol Prior
keycode 100 = Left NoSymbol Left
keycode 101 =
keycode 102 = Right NoSymbol Right
keycode 103 = End NoSymbol End
keycode 104 = Down NoSymbol Down
keycode 105 = Next NoSymbol Next
keycode 106 = Insert NoSymbol Insert
keycode 107 = Delete NoSymbol Delete
keycode 108 = KP_Enter NoSymbol KP_Enter
keycode 109 = Control_R NoSymbol Control_R
keycode 110 = Pause Break Pause Break
keycode 111 = Print Sys_Req Print Sys_Req
keycode 112 = KP_Divide KP_Divide KP_Divide KP_Divide KP_Divide KP_Divide XF86Ungrab KP_Divide KP_Divide XF86Ungrab
keycode 113 = Alt_R ISO_Next_Group ISO_Level3_Shift
keycode 114 =
keycode 115 = Super_L NoSymbol Super_L
keycode 116 = Multi_key Multi_key Multi_key Multi_key
keycode 117 = Menu NoSymbol Menu
keycode 118 =
keycode 119 =
keycode 120 =
keycode 121 =
keycode 122 =
keycode 123 =
keycode 124 = ISO_Level3_Shift NoSymbol ISO_Level3_Shift
keycode 125 = NoSymbol Alt_L NoSymbol Alt_L
keycode 126 = KP_Equal NoSymbol KP_Equal
keycode 127 = NoSymbol Super_L NoSymbol Super_L
keycode 128 = NoSymbol Hyper_L NoSymbol Hyper_L
keycode 129 =
keycode 130 =
keycode 131 =
keycode 132 =
keycode 133 =
keycode 134 = KP_Decimal KP_Decimal KP_Decimal KP_Decimal
keycode 135 =
keycode 136 =
keycode 137 =
keycode 138 =
keycode 139 =
keycode 140 =
keycode 141 =
keycode 142 =
keycode 143 =
keycode 144 =
keycode 145 =
keycode 146 =
keycode 147 =
keycode 148 =
keycode 149 =
keycode 150 =
keycode 151 =
keycode 152 =
keycode 153 =
keycode 154 =
keycode 155 =
keycode 156 = NoSymbol Meta_L NoSymbol Meta_L
keycode 157 =
keycode 158 =
keycode 159 =
keycode 160 =
keycode 161 =
keycode 162 =
keycode 163 =
keycode 164 =
keycode 165 =
keycode 166 =
keycode 167 =
keycode 168 =
keycode 169 =
keycode 170 =
keycode 171 =
keycode 172 =
keycode 173 =
keycode 174 =
keycode 175 =
keycode 176 =
keycode 177 =
keycode 178 =
keycode 179 =
keycode 180 =
keycode 181 =
keycode 182 =
keycode 183 =
keycode 184 =
keycode 185 =
keycode 186 =
keycode 187 =
keycode 188 =
keycode 189 =
keycode 190 =
keycode 191 =
keycode 192 =
keycode 193 =
keycode 194 =
keycode 195 =
keycode 196 =
keycode 197 =
keycode 198 =
keycode 199 =
keycode 200 =
keycode 201 =
keycode 202 =
keycode 203 =
keycode 204 =
keycode 205 =
keycode 206 =
keycode 207 =
keycode 208 =
keycode 209 =
keycode 210 =
keycode 211 =
keycode 212 =
keycode 213 =
keycode 214 = XF86Display NoSymbol XF86Display
keycode 215 = XF86KbdLightOnOff NoSymbol XF86KbdLightOnOff
keycode 216 = XF86KbdBrightnessDown NoSymbol XF86KbdBrightnessDown
keycode 217 = XF86KbdBrightnessUp NoSymbol XF86KbdBrightnessUp
keycode 218 =
keycode 219 =
keycode 220 =
keycode 221 =
keycode 222 =
keycode 223 =
keycode 224 =
keycode 225 =
keycode 226 =
keycode 227 =
keycode 228 =
keycode 229 =
keycode 230 =
keycode 231 =
keycode 232 =
keycode 233 =
keycode 234 =
keycode 235 =
keycode 236 =
keycode 237 =
keycode 238 =
keycode 239 =
keycode 240 =
keycode 241 =
keycode 242 =
keycode 243 =
keycode 244 =
keycode 245 =
keycode 246 =
keycode 247 =
keycode 248 =
keycode 249 =
keycode 250 =
keycode 251 =
keycode 252 =
keycode 253 =
keycode 254 =
keycode 255 =
I didn't install something. Just stopped working. Any ideas?

Answer 1

Looking at your xmodmap output, I don't see any keys that are bound to the various multimedia actions.
Try determining the keycodes (of each multimedia key) via "xev" and then bind them to the relevant action (XF86AudioLowerVolume, XF86AudioRaiseVolume,...) via xmodmap.