Ok now im nuts,

**CelicaNUT** · 05-19-2004, 03:10 AM

Hi, im hoping for some advice from all you lot here as im at the point of giving up, basically the install in my car was working fine until i changed my headunit and now i pick up some serious noise (on the screen), i've tried everything, earthing PC, Graphics card, Inverter, you name it with no help, i've even tried a variable pot in the Composite line (TV out) and a smoothing Cap but still no joy, so as you can imagine im stuck anything else i should try?. Whats really doing my head in is the fact that before i changed the head unit it was fine!, is there (does anyone know) anything on the input of the screen to smooth the signal?,maybe i've blown this? also one other really weird thing, the signal will come through even if i connect the inner pin on the phono to the shield!, i don't get it, the signal comes through even if i break the wire and hold each end in my hands AND the signal is cleaner!, please any advise, so i can get this up and running again and finish the install. Thanks (and slowly going mad)

P.s before you ask i have tried disconnecting the new head unit and putting the old one back but the noise is still there.

**CelicaNUT** · 05-19-2004, 04:48 AM

come on guys and girls 20 views and NO replies, someone must have some sort of idea!

**Ormo** · 05-19-2004, 04:57 AM

Ummmmm.....

Check the wire hasn't been shifted when you were installing your new headunit. It maybe lying closer to an aircon fan or something now......maybe......

**Vicci** · 05-19-2004, 05:22 AM

Radioshack sells a number of line filters. You can try running a DC-line filter on your screen, but I doubt it'll help.

There's also a chance you've grounded your system somehow, and you're getting bleed-through on the screen (that's why the phono pin-> ground gives you an image). I'd check your wires (especially around the new head unit) to be sure you're not getting any grounding from pinched wires.

Also, see if you can isolate your head unit from your screen on a different fuse line. Perhaps using the distributor block as a kind of signal-filter may keep your (presumably more powerful) new head unit from messing up the screen. LCDs don't have the same kind of hold circuits as TVs and CRTs, so I doubt you could have blown something.

My last advice would be an odd one. You said you got a new head unit, you didn't by any chance change out your signal SOURCE, did you? This head unit wasn't one of the epia-boards-in-a-din units, was it? If so, you may be running into Sync Signal problems, since the older Epia boards only put out +3.3VCC (if I remember right) and some LCDs will only accept +5VCC. This is uncommon, but it happens with some of the older screens.

If none of this works, try disconnecting the new HU and powering up. If the problem ceases, it IS actually in the HU (which would surprise me, given the description you gave). If not, it was something the install did.

**craigyb** · 05-19-2004, 05:25 AM

The reason you can get a signal with just the center attached is everything is grounded through the car, it's just a big lump of metal, so unless you isolate the screen from the car power and ground it will always be connected to the PC and the car, so just the live (coax core) is need to feed a signal.

It's a good way of getting rid of ground loops, just connect the center wire.

Craig

**eCar™** · 05-19-2004, 05:58 AM

Try using another cable temporarily?

**Pokey** · 05-19-2004, 06:04 AM

Check ground.. Try grounding a cable and then running the other end to each one of your devices case, but remember, some deivices 'might' be floating their ground.

**CelicaNUT** · 05-19-2004, 05:59 PM

Thanks everyone ,something for me to try, i really am grateful as i was getting a little lost, i guessed something i did caused this, but just couldn't figure out what. Thanks again i will let you know how things go.