EnduroExpertFSR
Member
A6 Sound Board and A20 Auxiliary Sound Board LEDs.
Each of these two sound board have an LED. Both boards' LED should be flashing continually when the game is powered on. If neither LED is flashing (off), usually this means the sound board to CPU board connector at CPU board P4 is disconnected. Or there is no +12/-12 power coming from the Auxiliary Power Supply. copied from pinrepair.com
my sound board led lights and stays on, but is very dim... it gets +12.04 v and -11.98 v the auxilary sound board led sometimes lights sometimes doesnt, when it does light, it stays on. neither LED flash.
when i power up i get the dual screech, but the led's dont flash and i have yet to hear any sound other than static that gets louder if you turn the volume pot up.
2L. Sound Problems.
If either both Auxiliary sound power fuses F10 and F11 are blown, no sound will work in the game. If only one Auxiliary sound power fuse is blown, usually the sound will still work (just not as loud). Auxiliary Power Supply holds the sound amplifiers (TDA2040, but can be replaced with the less powerful TDA2030). Also the op-amp MC3403 (or LM324AN or NTE987) can be blown, along with the LM340T (or 7805) +5 voltage regulator. If the game boots with the "dual tone squelch" than the sound boards are working. The CPU board's A1P4 connector must be in place or the CPU board can not talk to the Sound board. If this conector is removed, the sound board won't boot properely and there will be no sound.
copied from pinrepair.com
both fuses F10 and F11 ohm good with .4 ohms resistance, out of the fuse holder.
P4 is plugged in at the CPU board. my +5 V is almost dead on the money at +5.03 V.
im at a loss any ideas?
Each of these two sound board have an LED. Both boards' LED should be flashing continually when the game is powered on. If neither LED is flashing (off), usually this means the sound board to CPU board connector at CPU board P4 is disconnected. Or there is no +12/-12 power coming from the Auxiliary Power Supply. copied from pinrepair.com
my sound board led lights and stays on, but is very dim... it gets +12.04 v and -11.98 v the auxilary sound board led sometimes lights sometimes doesnt, when it does light, it stays on. neither LED flash.
when i power up i get the dual screech, but the led's dont flash and i have yet to hear any sound other than static that gets louder if you turn the volume pot up.
2L. Sound Problems.
If either both Auxiliary sound power fuses F10 and F11 are blown, no sound will work in the game. If only one Auxiliary sound power fuse is blown, usually the sound will still work (just not as loud). Auxiliary Power Supply holds the sound amplifiers (TDA2040, but can be replaced with the less powerful TDA2030). Also the op-amp MC3403 (or LM324AN or NTE987) can be blown, along with the LM340T (or 7805) +5 voltage regulator. If the game boots with the "dual tone squelch" than the sound boards are working. The CPU board's A1P4 connector must be in place or the CPU board can not talk to the Sound board. If this conector is removed, the sound board won't boot properely and there will be no sound.
copied from pinrepair.com
both fuses F10 and F11 ohm good with .4 ohms resistance, out of the fuse holder.
P4 is plugged in at the CPU board. my +5 V is almost dead on the money at +5.03 V.
im at a loss any ideas?