Working on retro computers is a fascinating and frustrating process at the same time. Fascinating because we can challenge obsolescence itself, and frustrating because time always takes its bite. In the case of the Toshiba Libretto 50CT that Polymatt on YouTube decided to restore, there are two problems: a password that is very hard to remove, and the impressive deterioration of its plastic case…
The Toshiba Libretto 50CT is no stranger to us. Colin from the channel This Does Not Compute restored one in February last year, and even with the right tools, he had to face several challenges. However, the situation of the 50CT that Polymatt has in his hands is much worse. First, its unknown password requires a special hardware key to be removed from the system (removing the CMOS battery is not enough), and secondly... the plastic. The entire Libretto series is known for its tendency to "return to oil", with cases that are falling apart after three decades...
A new case for a 1996 laptop
Polymatt decided to attack the screen first. The laptop doesn't put up much resistance to disassembly (unfortunately, we can't say the same about modern PCs), but if the final goal is to remodel the case, you have to collect every single piece without exception. Unlike what we observed in the repair of the 'vinegar syndrome' that affects many LCDs, accessing the panel and the fluorescent lamps is not such a traumatic process, although it demands great respect. By far, the most delicate part is soldering the backlight wires to the new tube. Any mistake is very costly here.
Back to the case, Polymatt explains why the deterioration is so advanced in some sections: The top part combines ABS plastic with polycarbonate and fiberglass reinforcement, but the bottom section is only polycarbonate with fiberglass, and it loses integrity over the years. The design is based on building primitives, and the use of a scanner to calibrate the position of the most important internal elements, but the prototyping phase is inevitable. Despite the best calculations, everything is a balancing act, and there will always be the possibility that the plastic behaves unexpectedly before, during, and after printing.
The most absurd part? Perhaps not even that is enough: Polymatt had the idea to print the new parts in Nylon PA 12, but he had to settle for his own prints because the material simply didn't respond well to the shape of each part. What happened to the BIOS password? In the end, he created a custom PCB (with some later modifications) that replicates the function of the original key. That key works via parallel port, which in turn requires a dock, but the PCB connects directly to the socket on the bottom of the laptop.
In summary, the project ended with a bitter taste due to the nylon problem, but the mission of creating a replacement case for the Libretto line was certainly successful. Polymatt published the files on Printables, and anyone interested can download them for free.
Access the files: Click here
