Possible AUTO ON for all In-Car LCDS?

**mrcanngo** · 08-24-2007, 06:15 AM

So, who here as ever relocated their power button on their LCD to another location? I did.

I'm sure lots of you guys out there have. The other day, my friend and I made an accidental discovery with his our LCDs.

We used a momentary switch that is normally closed. We had both thought it was normally open and just settled with the fact that we would always have to push it but we discovered otherwise.

Now, whenever we turn on our cars, the screen comes on automatically because of this normally closed switch.

My question is, will this burn out the switch on the lcd in anyway? Its been installed for a week now and still no problems.

This has worked for those cheap LCD's that armen sells at digitallww. Model number TM-720TS.

Can anyone else try this out with their LCD? Just hold your "on" button down while you power on your car and see if it stays on. If it has worked and there is a general consensus that it is safe to do, we have found a cheap and easy way for having "Auto-On" in some LCDs.

Good luck! (Yes i know that Lilliput and Xenarc already have these capabilities)

**swift_gti** · 08-24-2007, 07:18 AM

You could also wire it up to a relay with a 555 timer so when power is applied the circuit is closed by the 555 timer and then it releases until the next power cycle of the 555 circuit. This is how I turn on my carpc (a laptop) it just simulates pressing the power button.

**peijffertje** · 08-24-2007, 03:55 PM

I have a DWW-700H and I tried it but it didnt work.

**mrcanngo** · 08-25-2007, 02:54 AM

aww that sucks, i was hoping this would work with all touchscreen lcds. I guess i was lucky that the cheapo $200 screen has this neat trick to it.

Any other tries?

**sfenzi** · 08-28-2007, 08:59 AM

I have an indash LCD model XDXP070ID which doesn't have auto on. I tried holding down the power button while turning the carputer on and the screen came on. Does this mean that if I change out the switch to one that is normally closed I'll have Auto on? I'm getting excited!

**MatrixPC** · 08-28-2007, 09:33 AM

Most if not ALL Lilliput screen can do that.
There are documentation regarding to this "auto-on" on Lilliput AKA "jammed the power button". I think the Lilliput sticky "everything you need to know about Lilliput" thread had it.

BTW, does your other buttons work? The Lilliput doesn't, With this method, the only way to move around the screen setting is the remote.

**sfenzi** · 08-29-2007, 10:31 PM

I tried just jumping the power button. Now the power button doesn't work and it doesn't auto-on. But all the other buttons still work. Any ideas why this would be?

**godraj** · 08-30-2007, 12:01 AM

Probably not the best thing for the monitor, but I found the 2 wires that leave the button board and go to the main board. I put a capacitor in between those 2 wires. So now anytime power is supplied the screen turns on, however it takes about 30 seconds for it to discharge. So I can't power the car off and turn it back on immediately.

**MatrixPC** · 08-30-2007, 11:46 AM

Originally Posted by godraj

Probably not the best thing for the monitor, but I found the 2 wires that leave the button board and go to the main board. I put a capacitor in between those 2 wires. So now anytime power is supplied the screen turns on, however it takes about 30 seconds for it to discharge. So I can't power the car off and turn it back on immediately.

You probably have to switch to a lower/smaller capacitor.
Maybe this thread can help you.
http://www.mp3car.com/vbulletin/lcd-...ut-screen.html

**sfenzi** · 08-31-2007, 09:28 AM

So godraj, do you think I'll fry something by having the power button basically on all the time? I think this was mrcanngo's main concern with his mod.

Martixpc, I'd like to adapt the "jammed the power button" mod to my screen but the layout is different. I'm going to open the screen back up and see if I can figure it out. I'll try to take some pics.