QuestionQUESTION: Hi, I brought a 1998 BMW 540i manual with navigation sys last month. The audio system was not working at that time, but on board computer display was ok. Even though radio frequence and cd track displayed on the screen, I couldn't hear any! First I thought head unit maybe was the problem, so I replaced to widescreen head unit, but no sound still. Then I thought maybe was the amplifier because I didn't see DSP option on screen, so I replaced amplifier. The result was same--no sound. Now I really don't know how to do. I really don't want to go to dealer that will cost me arms and legs just checking. What I can do??
By the way, the noise from rear deck when it passed uneven road. How to fix that?
The VIN:WBADE5324WBV94857
ANSWER: It sounds like a bad amp.Are you sure the new one is good or did you buy it used? The amp failing is very common and almost guaranteed when you have no sound but screen functions are working. Also double check that any mini coaxial cables(at the amp) are properly installed or were missing.
Kimber
---------- FOLLOW-UP ----------
QUESTION: Thanks for your answer. Yes, the amp is used from ebay, but seller guarantee to be good condition. Do you have other way to test amp? I am not pretty sure which coaxial cables need to connected to amp! There are three coaxial cables--one connect to radio unit, one connect to amp, and one connect between trimble and CD changer, right?
AnswerI hate to say it but installing a known good amp is the best way to check. Check for power and ground to the amp and it sounds like you coaxials are correct. Maybe also plug your old nav screen back in. I assume you have NAV since you installed the wide screen. If you don't have nav the radio could also be the problem(located in trunk). Let me know about power to amp. If you have that 90% of the time thats the problem.
Kimber
