问:坏的仪表板

嗨,我有一个04 qx56。我有问题仪表组。我已经修了4次了。我有仪表卡住的问题。我有一个仪表板灯闪烁。这种情况有时当我打开车。好像每次我把它修理它只适合3 - 4个月。在过去的一周我一直在dash灯闪烁。正确的信号光不会显示在仪表盘上。我能听到,但它不会出现在那里。 The RPM gauge is stuck. And the gas one will be low when I know I have more than that. The shop where I was having it repaired is refunding my money back because they were not able to help me after 4 attemps. I would like to know if I should replace the unit with a new one or could it be something else that is causing the unit to go bad? Thanks in advance for your help.

我的车有149000英里。
我的车有一个自动变速器。