Help! Instrumental panel fail

[timtian]

I am new here. I don't know if I can get any help here. I have an Infiniti G20. Months ago, the instrument panel started to fail when driving for a while, especially during the hot weather. Speedometer, Tachometer, and temperature gauge all went down to zero, or sometimes went down to the other end. If parked there for a while, everything will go back to normal. I already followed the dealer's suggestion to replace the circuit-board at their place. However, only driving like two weeks, it happened again. This time they tried to convince me to replace the speedometer, but I don't want to replace the speedometer then in the future they tell me I need to replace another part. I want to ask if anyone by any chance knows what might be the real problem? Thanks a lot.
Modified by timtian at 8:14 PM 5/31/2007