Not your typical flicker problem
Hi, I've been tackling a problem for quite a while with nosie on my screen. This is not your normal engine nosie, alternator nosie or bad ground nosie I've read here, it something much worse outahere
Basically I am seeing very faint nosie in the video. lines of movement. It seems to happen when the computer is doing things, I notice it more if theres video activity like scrolling songs in a play list. But its also can be when the screen is stactic. Think of the noise you hear when your plugged into analog speakers amd volume is turned up.
Now, what makes this problem so complicated for me to put my finger on is this. This is the second computer in my car thats doing it. First was a moca 7043 and I was viewing it on my BMW nav screen. Since then I completely upgraded my system. New Sumicom 620, P1900 psu, EZpro power controller, EZTank, Tank battery and some other hardware not worth mentioning. I thought I was going to leave this problem behind but low and behold I was wrong. The problem still exists and even worse, or it was worse at first. I have tried many things, Ground wires up the wazoo even though I tought I had a pretty superior power setup. Still no go....In thinking it was some of the hardware I just had the computer hooked up to the psu with video and still no good. Hmm, then I thought, lets just hook the PSU up to the tank battery alone. Wow, clean video when not connected to the car. Okay, lets try the AC adapter powered outside the car...looks good again. Now try inverter and ac adpapter in car, still looks good. I saw some other noise differnt from my original problem like rolling lines but I guess the inverter shouldnt be too close to the pc. So I was able to get clean video with the interver and AC adapter. I was good for a few weeks and then I decided I didnt want to use my BMW nav monitor anymore, I want touch screen and crystal clear VGA ( this is what happens when you hang on this website). Besides, I hated having to use the inverter. I thought my problem would of went away when going VGA but that was wishful thinking. Still same video noise problem. I bought a Zenarc, btw.
Oh, did I mention this happens when the car is off too. Okay, so ive been reading and reading and I tried a few more things. I put the VGA on a inverter and AC adapter (was using cig plug before) and the video was perfect. Now I am scratching my head, are you with me so far. I read about regulated PSU's and then proceeded to hookup the small OPUS POL dispite that some of your guys dont recommend it. Its safe to say that after two hours of having my computer running with car off the screen goes on without engine runnnig and looks as bright too. I have my screen turn on when key is turned, I like it better this way so of course the screen turns off when cranking. I may do the USB mod and if the opus gives me greif I have a ITPS I could replace it with. Okay so after I hook up PSU, still no luck same nosie problem.
So lets break this down..the only thing that works for me is when the computer is running on its own power or when the computer and monitor is running off of seperate power sources. I suppose if I had a way to power the bme nav from another powersource the screen would of looked good too. The only PSU I tried so far is the P1900. I dont think its the psu, oh, I also tried a 20amp 12V noise filter from RShack. that didnt work at all. So if this is still a grounding issue I dont know where else to put a gournd except somewhere on the motherboard. The only thing I havent done is go into the pc and run a heavy gound out from the PCB. I dont think the case is gournded to the mobo well other then the ports in the back, ie VGA, USB, power. Sinice all of my tweaking and putting really good grounds in and grounding wires at their shortest distances it has improved the screen some but I can still see nosie.
Sorry for the long post, been up all night and my carputer is still at 90%