HDMI Signal Tricks?

Thread Starter

bumba000

Joined Oct 7, 2015
89
Hi All,
So this is gonna sound nuts, but here we go. I have this laptop and it's become quite finicky. It will not power on without an HDMI cable being connected to my TV. Once connected and powered on though it works just fine so long as I don't disconnect the TV. If I do that the laptop takes a nose dive.

I'm wondering how I might trick it into thinking that it's connected to a TV via HDMI. ** For example shorting two pins with a 10k resistor etc... **

Thank You,
John
 

Thread Starter

bumba000

Joined Oct 7, 2015
89
100% crashing. if I plug and unplug the hdmi cable a few times after crash i get a blue screen, pink screen, fuzzy screen, green screen, lime green screen, fuzzy screen, orange screen, then windows again, but I can't do anything with it. it's completely frozen.

The other end of the cable was plugged into my TV and is now plugged into a driver board for an LCD screen I'm using for my raspberry pi 3. I have the screen controller in USB mode, but plugging the hdmi cable from the laptop into that lcd controller's hdmi port makes the laptop screen work and also makes the machine boot up. I know it's crazy. trust me - I know. I've been at this for hours and hours now.

If I can chop off the end of an hdmi cable and short a couple of wires with a resistor or something. I'm good with that. I'll leave that sucker flopping out of the laptop while I use it.

Thanks, John
 

Thread Starter

bumba000

Joined Oct 7, 2015
89
HOLY CRAP! I've got it! Ok

on the right side of the HDMI cable is 5v+ on top and "Hot Plug Detect" on the bottom. Shorting them with a 1k resistor does the MAGIC!

Sure is too bad my kids don't dig this stuff. I'd sure love to share it with them.

You're all great though. lol ;)

Thanks boys!

John
 

Thread Starter

bumba000

Joined Oct 7, 2015
89
Ok. I have a bunch of LCD screens laying around, so I picked up a controller board for one of them to run my pi on. that controller has an hdmi port on it. After having issues with the laptop and finding that the hdmi on the tv seemed to remedy the problem I tried connecting the laptop hdmi port to the lcd controller board just to see if that too would remedy the laptop issue. it did.

 

Alec_t

Joined Sep 17, 2013
11,991
Does your laptop have a function key to select its own display screen and/or an external display screen?
If so, does that function setting get remembered when the laptop goes into sleep/hibernate mode?
 

Thread Starter

bumba000

Joined Oct 7, 2015
89
yep it sure does. and it will cycle through all attached display devices when pressing fn + f4. it just wont work without the hdmi being plugged in. or in this case jumpered with a resistor. I've gone as far as wiping the hdd, re-installing windows and then flashing the bios. I'm 100% positive that any pre-setting would have been erased. that hdmi connection is key here for whatever reason.

Thank You,
John
 
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