Lilliput GL-701 & Interference? - Not sound related? - Please read.

**OptimusPrime** · 06-23-2007, 08:12 AM

I have installed my Lilliput gl-701 screen and i seem to be having some interference...

This one

I hooked it all up firstly using the standard headunit wiring, as to be fair the wires were fairly chunky. But i found i have a whine while the engine is off, plus the infamous alternater whine with the engine running.

So i disconnected all the VGA cables/RCA's etc, just leaving the power connected. Yellow, Red & 2xBlack. Still the same.

I have now earthed the 2xBlack wires (together) directly to the chassis and a seperate fused wire from the battery for the power (Yellow). Red (acc) is still connected to the original HU wire.

I am still getting the noise

. I have also noticed that there is some interference in the picture and has been from the beginning.

The noise is still there with the inverter & PC off. There is no change what so ever with either the Inverter & PC on or off.

Can anyone help sort out my final problem?

Thanks

OP

**OptimusPrime** · 06-25-2007, 02:47 AM

Anyone got any suggestions?

I have gone through the FAQ and done a fair bit of searching, but still nothing

A few facts.
My power cable is a fused 16awg direct to the battery.
My grounding cable is 12awg approx 6-7" long, bolted cleanly direct to the chassis.
PC is off.
Inverer is off.
RCA's are disconnected.
VGA is disconnected.

Options i need advice on
Would running the negative back to the battery be any good?
Can i earth the negatives on the speaker wires?
(Clutching at straws now

)

Cheers

OP

**AJWatU** · 06-25-2007, 01:24 PM

your alternator is working to hard buy a bigger alternator.

**OptimusPrime** · 06-26-2007, 02:52 PM

Thanks for your input, but its definatly not my Alternator...

Any other suggestions?

OP

**AJWatU** · 06-27-2007, 03:12 PM

Sorry but didn't you say your alternator was whining? That is usually a pretty good sign your alt is trying to hard. I guess you weren't asking about your alternator. My bad

**OptimusPrime** · 06-28-2007, 02:07 PM

Originally Posted by AJWatU

Sorry but didn't you say your alternator was whining? That is usually a pretty good sign your alt is trying to hard. I guess you weren't asking about your alternator. My bad

Apologies if i sounded offish, it wasnt my intention. I was just in a hurry at the time...

I would say its definatly not my Alternater, because i had a new (4 months ago) uprated alternator & battery to ensure i had no problems with my 2 JL 1000/1 amps (2000w rms total). I'm sure if my alternater can handle them, they could handle the less than 20w from my screen (its probably more like 5w as the whine is the same with the screen closed and just the radio or any other option on).

I am also steered away from my alternater as the whine is there while the engine is off. (I may be misleading myself on this one)

I am going to try re-earthing again, although i don't think it will make a difference as i made sure my grounding point was a good one (drilled then paint cleaned around the area then bolted to bare metal).

Something to note though, my unit comes with 2 ground cables. i presume it makes no difference grounding to the same point...? (strange it has 2 though)

OP

**EricE** · 06-28-2007, 06:49 PM

I don't think you want to power your LCD that way. That is how I did it (at first) and I had lines through it all the time. I redid it to use the power and ground from my computer power supply and that fixed it right up.

Oh, your are using an inverter. Those are notorious noise makers. Sorry, I can't help you.

**AJWatU** · 06-29-2007, 12:03 AM

Yeah I just reread everything again and noticed the inverter I would tell you the same as eric. Just buy a DC to DC regulator. I would say interfernce on the screen is a sign of dirty power. I'm not sure about whining thats almost alwas a ground or your rca are to close to your power wire. Also you said your alt was making a whine then later you said your car was off but still making the whine. Thats confusing alt doesn't move when car is off. so not your alt. Nice amps thats all I buy is JL

**OptimusPrime** · 06-29-2007, 11:37 AM

I realise an inverter is not the way to go, but with my monster 400w psu i havent got many options...lol

Anyway, inverter and PC aside as i get the noise whether the inverter is on or off.

RCA's and VGA's disconnected, so it cant be them being too close to the power cables (although they are running down the other side of the car anyway as a matter of caution).

I will look at powering my screen via my PC (as the power is more stable), but as it designed as an in-dash screen and can be used stand alone, so it shouldnt really be a problem.

Something i found very strange earlier...

I was redoing all my cables incase i had nicked one somewhere, connections loose etc, i forgot to reconnect my ground cables when i turned on my screen. My screen came on, which i find odd. So i experemented by touching them to ground and it made no difference what so ever?!?!?

I am still getting a noise (constant whine) when the engine is off and then it raises and lowers with the revs with the engine running...

Should my screen work when not grounded?
Is it getting its gound elsewhere?
Have i got an internal wiring issue?

Cheers

OP

**Switt23** · 06-29-2007, 05:44 PM

Things I would check...

1) Make sure all your grounds are good ones. No paint or surface dirt. If the Ground is part of the chasis that is unseen, take a screw driver and scrape the area clean first. By doing so you elminte any chance of clear coating or paint.

2) You mentioned that the RCA's are on the opposite side of the car, do they get close towards the firewall?

The problem sounds definately like a ground loop with a live wire thats always live. If that makes since, your power source is coming off the battery or a fused circut?

You mentioned that the LCD is coming on without the ground... There is a cut somewhere in the wire because that unit shouldn't power on unless it's grounded. So it's grounded somewhere and is picking up interference.

CHECK YOUR GROUND WIRE ON THE LCD!