AOC portable monitor graveyard

This pile was a pickup from work. Apparently, auditors are extremely rough with their kit and these AOC Portable monitors are not upto the task and the USB 3 Mini B connectors all gave up the ghost. Out of the pile, there was 4-5 that were totally dead with smashed screens that I stole the USB and controller boards from, hoping that I might be able to use the parts to fix some of the others. The rest of them all had bad USB connectors on them that needed to be replaced, this was verified by find one good connector and testing each screen to check the rest of it worked other than the USB port.

Repairs

Fixing these boards was a bit of a pain due to the connectors that they used. The micro b connectors were surface mount and were a specific type that I had to order twice as I got the connector mounting pin type wrong. You can only replace these with the hot air station and it is fiddly. Some of the screens had type A connectors and were easier to fix. I actually had to get my dad to help with some of these connectors as my hands were not steady enough to do them. In total I got 14 working screens at the end of it.

Mini Pedal Board

After building my big pedal board for 10 pedals I STILL had left over pedals that I had built and didn’t really have a ‘bedroom’ setup. So I set out to build a smaller 4 pedal version of the unit I had already built complete with the comic book covering.

Power Supplies

My dad had revised his power supply board design to be simpler and easier to build with the only difference with this build is that I went for 9V only pedals so I could make all the power supplies the same but also allowing me to get 12V AC if I wanted to run a tube pedal from it. I built two boards and then only realised that I only required one for my project.

The Build

The build process was much the same as the larger one but I simplified the process and kept it essentially a square box with no back so the power supply and cables could sit out the back.

The Final build turned out really well and matches the big unit in my other post. The pedals are:

  • MXR Jimi Hendrix UniVibe
  • EchoRec Clone
  • MKII Tone Bender
  • OCD OverDrive Pedal

AST 386 laptop resurrection

As another find at the retro computer day I picked up these two AST Premium Exec 386SX’s that both looked pretty interesting and being the same machine I figured if I could get one to work out of the two of them then I would be in luck. I was in the zone to try get old machines working again and give them that new lease on life so I figured i’d take on the challenge and it might even pay for some of my other purchases.

Condition

The condition of the units wasn’t overly great with one of them being in good condition and the other one having a cracked screen hinge. Both had battery corrosion and would not power on so some deeper issues lay ahead.

Power Up

Because the batteries were dead I had no immediate way to power them up and it turns out that these machines used a very strange power connector that nothing else used. But a quick bit of googling later and I found that the connector was sold at Jaycar and all the pins were actually just 5V and Ground so I wired them up and they sprang into life, kind of. One of them worked but one of them didn’t. There was a couple of capacitors that I had to replace to get it to power up.

Operating Systems

I was hoping I could load up some old DOS games on these machines but that dream was quickly dashed when I realised these had STN panels in them, something that was not great for much, especially games as they are really blurry. I did manage to get Wolfenstein 3D working on one, although extremely unplayable due to the screen. These machines are also only black and white.

I ended up loading DOS 7.1 on one of them via floppy and Windows 3.1 on the other.

Gut Shots

All the internal batteries were dead as well as the backup batteries and one of the harddisks, which I swapped with a IDE to CF adapter. These machines had a hard limit on the size of the HDD they would see so getting anything bigger than 2GB to show was not easy, but I got there in the end.

LCD ASCII Binary learning box

After seeing a video by the 8BitGuy on how an LCD Display works I remembered I had a bunch of 20×4 LCD screens sitting in a box and most of the parts and figured I could use some of these old parts up and make on one these boxes. I basically followed the tutorial in the video and wiring it up directly how he did.

Wiring it up was pretty straight forward although I did run into a few issues that were explained in the video. I did not realise that binary numbers read LEFT to RIGHT, 7 to 0, not the other way around so Although I could get the capital letter B to work no other characters worked ( Capital B is the same backwards and forwards incidentally ). This is when I realised I wired it up backwards and had to reverse the switches left to right and make a new label. Another thing that was discussed in the video was the value of the resistor that pulls the enter switch to ground, I used a 100k resistor at first and realised it was too high, I then dropped it to 10k or 1k ( cant remember ) and tested the button and when you press the button it would over come the ground and give the switch 5V as expected.

So all in all a pretty cool little build and a cool little learning tool for understanding how binary works and how LCD displays work. Now I just have to remember all the 1’s and 0’s to make it work!

Asus RT-AC68U firmware corruption

After getting stuck with a new internet provider and no router for weeks I decided to get an Asus RT-AC68U off trademe to both have a router and to get better performance and more control. The router was performing great for months until it started having random power offs and not coming back up with the correct IP address. I would have to power cycle it numerous times to get it to come back up and then it may only last for a few days before it did it again. I looked in the logs and there wasn’t anything specific but everything pointed to either faulty hardware or corrupt firmware. I swapped over the the ISP provided router that eventually turned up and attempted to update the firmware, then the issues began.\

Updating the firmware

Well updating through the UI just was not working, every time I tried to upload the official Asus firmware it would just error out and say the file was not compatible, even trying 3rd party firmware gave the same results. There were 3 options for me to try:

With no positive results I decided to strip down the device and see if there was anything obvious wrong with it ( overheating etc ). Nothing came of that but at least I could see the Serial port to program it if I needed it.

I did some more digging and found that there was an Asus Firmware Restoration tool for Windows, this was promising. To use the tool, you had to put the router into recovery mode but holding the reset button then pressing the power button and keep holding the reset button until the power LED starts flashing slowly, then you open the software, plug in an ethernet cable directly to the router and upload the firmware.

I tried multiple versions of the firmware with little success, all of them failed to upload. I eventually got one to upload and the router kicked back into life. One last issue I was facing is that the settings were all messed up and still giving errors. Turns out even after a firmware update the flash BIOS still holds the settings! You need to hold WPS button while powering it on until the power LED flashes fast, then you let it go and leave it until the unit comes back up. This is how I ultimately fixed it and got it to run the aftermarket Merlin Firmware as after the flash BIOS was reset I could successfully upload the Merlin Firmware using Asus’ tool and it has been stable ever since.

The working unit after months of being powered on with no issues.

Here are all the files I used to do this if anyone needs them.