This Amdek Video-300A amber composite monitor came out of e-waste with a big chunk missing from one rear corner of the case. I went ahead and gave it a first look, checked the controls, and noted that both brightness and contrast were already turned all the way up. The monitor still had its front anti-glare mesh in place, and around back it was a simple composite setup with a few adjustment controls.
I connected it to a video tester and powered it up carefully with the front controls turned down partway. The monitor came up with an amber raster, and once it warmed a bit it showed a usable picture. The vertical size was off, so I adjusted it with a non-conductive tool from the back until the test pattern filled the screen properly. With the grid and checkerboard patterns up, the tube looked better than expected and bright enough to use, even though the controls were near the top end.
With the picture looking decent, I opened the case to deal with the broken corner. The good news was that the missing plastic piece had fallen inside the monitor, so I didn’t have to fabricate anything. Before going further I discharged the CRT, then checked the inside over for obvious problems. Internally the monitor was remarkably clean, with very little dust and no obvious capacitor issues, and it looked like a low-hour unit.
For the case repair, I used acetone to bond the broken ABS plastic back together. The first pass held in one area but let go slightly along part of the crack, so I redid it more carefully. I wicked acetone into the crack from the inside with a small squeeze bottle, then trimmed a couple of internal plastic pieces and used them as reinforcement on the back side where they wouldn’t be seen. That left the corner feeling much more solid without changing the outside appearance much.
Once the case was structurally sound, I cleaned the exterior with Windex and worked over the built-up grime. One rear label had come loose in my hand, so I reattached it with crafting adhesive. There was also some old foam tape residue on the side that took several rounds of Ronsonol lighter fluid and scrubbing to remove. The broken corner piece was a little more yellow than the surrounding plastic, so I gently blended it with a melamine sponge.
The front mesh screen needed a lighter touch. I cleaned around the bezel carefully, brushed the mesh with a clean stiff brush, and removed a cosmetic scrape with a little saliva and my fingertip. 😊 To finish things off, I applied 303 protectant to the plastic and wiped it back off as directed so the case had a little UV protection.
For the final test, I hooked the monitor up to an Apple II setup and checked text readability, then made a quick vertical linearity adjustment from the rear controls. After that I switched over to an enhanced Apple IIe and loaded up Oregon Trail.
The monitor ended up working well, the amber picture looked great, and the cracked case was back together cleanly enough to keep this Amdek in my collection!
— Aaron
Timestamps
00:00 – First Look
07:14 – PCBWay Ad
08:15 – Fixing The Crack
16:23 – Cleaning Montage
19:21 – Final Test
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