Lockdown Monitor Refurb

So, approximately 18 months ago I was updating my garage workshop, trying to get it organised with all the electronics and 3D printing bits and pieces I was working on. I figured I would get a cheap computer monitor to mount to the wall to do CAD design with (on Fusion 360, usually).

I went to my local dodgy PC store and bought the cheapest monitor they had. £15, done. But of course: pay cheap = get cheap. It didn't turn on.

I was planning on stripping it down anyway to mount it as flush to the wall as possible, so I continued with this to try and see what the issue was. Looking at the power supply board, it appeared that a few capacitors had popped, along with the rest of the board looking a bit old.

I traced the circuits and realised that the power supply was in two sections - one side reduced mains voltage to 12V DC, whilst the other side took the 12V DC and powered the backlights. The 12V DC was also sent to the main processing board.

I thought "great, I'll just use an external 12V DC supply!", as this would allow the low voltage section to be exposed and reduce the risk of electrocution from a 3D printed mains box.

Now I had a plan, I proceeded to chop the power supply board in two and solder new wires to move power around. I attached a barrel jack for a 12V connection and even 3D printed a new slimline circuit board bracket.

Happy that everything was all connected up, I plugged it in and attached it to my laptop.

....nothing.

Still wasn't turning on. What was wrong?

I started some diagnosis - firstly I unplugged the backlights and tried again. Hmm, I could see a faint outline on the screen now. Seems that the LCD and control board were ok.

Next I unplugged the control board and plugged the backlights back in again. What happened? They started flashing, as shown in the video. What was causing this? I reckon it's a power supply issue. I'm probably not using a powerful enough 12V supply, so when the backlight turns on it starts to use too much current for the power block to supply, so the voltage reduces and it turns off. Now it's not drawing any power, the voltage rises back to 12V and it tries again. This happens pretty quickly, so all I see is the flashing light.

I can't find a more powerful 12V supply, so I put the screen on the desk and walk away.

Fast-forward to Lockdown 2020 >>>>>>>

So, here we are in these unprecedented times. We're locked in our own houses, working from home for the first time ever.

I have my work laptop and a screen from work, but I don't have a screen that's compatible with my own laptop (what is the point in displayport when HDMI works perfectly well...), and I have plenty of spare time for 3D design on Fusion 360.

I dig out some old LCD panels I have lying around. One is from my old laptop, I spent about 8 years looking into that screen before the laptop died. It might work, but requires a driver board for £25. Not something I'm willing to spend.

I find another screen from an older laptop, but same story with the driver board.

Then I realise I have another screen, with a driver board, just lying under a pile in my garage. I dig it out, refresh myself on what it needs, and have another search for a power supply. And look what I find, 12V, 5 amps, that should be plenty enough.

To make sure any power issues weren't caused by the cable itself, I added a couple of capacitors to the circuit board, just in case it came a bit close to the voltage dropping and resetting the display.

Sure enough, when I plugged it in, it all worked! Finally!

But since my original plan of wall-mounting it, things have changed and I needed to have it on the desk in the study. It had to fit somewhere between 2 laptops and another monitor, so I figured I'd utilise the space underneath the monitor and have a sloping screen, ideal for 3D design. It would almost be like a miniature drafting table.

To do this, I needed to build some sort of stand. Of course this is what the 3D printer is best for - custom designed 1-off prints.

Using Fusion 360 and some digital calipers I drew up the screen and the key mounting points. Using this model, I manouvered it until I was happy with the angle and drew up some support legs.

I didn't want to waste time tidying up the printed part, so I ensured the design enabled no supports and double checked my measurements.

As it didn't need to look pretty, I just put the print settings to a fairly thick layer for a quick print.

Sure enough, they printed perfectly first time. No wasted plastic, no wasted time.

It only took 18 months, but how great does it look?