Repair – TeelSys

There are many topics this week to cover, thus the reason for the non-descript title. Some of the things that have come up this week are Psion and Ericsson repairs, ChatGPT and DeepSource, and Agile2023.

Psion and Ericsson repairs

I was able to carryout another screen cable repair this week on the Ericsson MC 218. The MC 218 had the hooks in the back for the lid hinge so this repair resulted in a good as new repair. It did pose a challenge as the hinge is really not designed to be put in place while connected to the screen. I feared that I was going to break the plastic hooks so I worked to remove the pins holding the wire hinge from the screen. It was not easy and after I removed them, I saw that doing so caused a different challenge. The pins holding the wire hinges in place are actually spring metal wound up into a pin shape. This made them difficult to put back into place. The removal of the pins did make it much easier to get the wire hinges over the plastic hooks without breaking them, but I do not recommend doing that. If I carry out this repair again in the future, I plan to figure a better way to choregraph putting it all back together without breaking the hooks.

I feel that the terminology that I’m using to describe the hinge mechanism on the Psion 5 Series devices is not correct. If Martin Riddiford or anyone else in the know happens across this post, please add a comment below to let us know what the proper names for these are. Also a drawing with text pointing to them would be awesome as well.

I captured a video of the repair and hope to find some time shortly to edit it and post it to YouTube. I will post an update with a link to the video once it is available. In the meantime, here are some screen grabs from some of the video to show the hinge assembly and the spring metal pins referenced above.

Screen with annotation for hinge wires and sprint metal pins — Screen with showing wire hinges and spring metal pins.

Unit with annotation pointing to one of two hinge hooks — Unit with showing one of the two hinge hooks.

Disassembled unit with annotation pointing to other hinge hook. — Another view of the hinge hook.

Hinge Repair

The hinge repair that I carried out last week, did not last long, which was not too much of a surprise. The metal pins bent and allowed the hinges to pop out from under the cover. I straightened the pins and used my 3Doodler, to add some PLA around the pins to give them a bit more strength so they hopefully will last a bit longer. The repair looked ugly but no one will see how bad I am at using the 3Doodler.

The opening and closing of the unit is very tight after the repair, which makes me a bit uncomfortable so I will take it easy when opening and closing the unit.

ChatGPT and DeepSource

It looks like things may be starting to really take off in the Artificial Intelligence (AI) field. We are starting to see more and more application of AI in some of the products that we use. I had been following the latest news regarding ChatGPT and found it interesting that it was able to pass a law exam at two different universities. While it would not be at the head of the class, it is good enough to get a passing grade. This presents a lot of challenges for professors at universities.

I had not given it much thought until I saw a video, 10X Your Code with ChatGPT: How to Use it Effectively, by Dave Plummer showing how ChatGPT could be used by software developers and others. He showed how he was able to interact with ChatGPT to develop a small software application and how we all need to start to understanding how to use the tool in our workflows.

I have seen that Visual Studio is now prompting me with code completion, based on my previous actions and where I’m at in the code. It is kind of freaky seeing the IDE basically writing code for you. There were times that it seemed to get in the way but most of the time, it was a real time saver. I’m sure it will get even better in the near future.

We may be at at point in time when AI will really start to have an impact in how we work and in our daily lives. Let’s just say that it has my attention now.

DeepSource

As I was trying ChatGPT, one very good use case popped out, and that is to do code reviews. Typically I am a lone developer and one of the biggest disadvantages of being a lone developer is your code is rarely code reviewed by anyone. ChatGPT did a fairly good job but the length of code it can code review is very limited.

Looking into ChatGPT led me to look into tools for Code Review. I found an article at GeekFlare, 6 Best Automated Code Review Tools for Developers. The article listed DeepSource as number 3. I looked into the other options and settled on DeepSource. It has great integration with GitHub so it scans code each time it is checked in. I was able to clean up my code fairly quickly.

I’ve made a recommendation to the DeepSource Team to incorporate AI for code reviews, particularly for us lone developers. We may be a few years away from being able to have a really good AI performing code reviews, but I think that is something we will see in the very near future.

Agile2023

I received some news this week that my submission for the Agile2023 conference was accepted. Now, I need to focus on polishing and practicing the workshop. This will be my first time presenting at a conference, so I’m nervous and excited for the opportunity. I hope it goes well and starts me down a path for the future.

I’ve had a busy week fixing items that have broken or that I bought on eBay that were for parts only.

Air Fryer

The Air Fryer, that we purchased on Amazon in March 2021 broke after 1 year and 10 months of service. At first, it would not shut off when the handle was lifted but after bumping it once, it shut off an would not come back on. I tool it apart to see if it could be repaired and found that the microswitch that turns the unit on when the handle is moved, failed. I was able to order a new one and replace it. It is working once again. Hopefully it will last a bit longer this time.

Curiosity got the best of me and I cracked open the microswitch to see how it failed as the failure seemed odd. The plunger on the switch was loose and I was not expecting that from a failed microswitch. Once it was cracked open, I could see that apparently the contacts had welded shut and created a lot of heat, which melted the plastic. It was a combination of these things that made it fail the way it did.

If interested, here are the links to the Amazon product pages for the Air Fryer and the replacement switch.

eBay purchases of Psion PDAs for parts

Phot from eBay auction with 4 Psion PDA devices.

I have an obsession for the old Psion PDAs and have an unhealthy collection of them. Lately I made a purchase of a lot with four defective Psion devices. The idea is if I can’t fix them, I should at least be able to repurpose the keyboard for some future project. (I’m also doing the same with the HP 95lx devices.)

Diamond Mako Revos

The lot of four Psion devices now has three functional units. I first worked on the Diamond Mako Revo devices. One unit was disassembled and the other one worked but needed to be plugged in as it no longer held a charge. I took to Amazon and purchased 4 Ni-MH AAA batteries with solder tabs. I was able to get both units working by replacing the batteries. I did have to use some hot glue to reenforce the lower pins holding the back cover in place. They seem to be brittle on both sides. A bit of carefully placed hot glue seemed to be enough to hold them in place.

Photo showing where the lower pin on the spring was cracked on the Psion Revos. — The circle shows where the lower pin on the spring was cracked on the both Revos.

I had another issue with the devices. At first, they did not seem to want to stay powered on even though they were plugged into the power supply. I could not figure out why the units would not stay on, so I started looking at them very carefully. I had discovered that the negative terminal in the battery connector had bent over and was touching the temperature sensor pin. It was not easy but I was able to straighten the pin and pulled the wire from the plug to make certain that it was fine. I carefully plugged the battery back in and they worked as expected.

What made this easier to figure out what was going on was by using the test points on the board. I was able to tell that the negative voltage was not where it should be, which led me to look closely at the plug and jack for the battery connection.

Photo showing the test points on the battery PCB — The test points on the battery PCB showing where the battery voltage should be present when all is connected as it should be.

David Savery’s post from 2004, on R3UK titled, Psion Revo/Diamond Mako Disassembly & Battery Replacement, was a big help in replacing the batteries in the Revos.

The two repaired Revos now hold a charge and live on once again.

Below is the link to the batteries on Amazon.

Kastar 2-Pack 1.2V Ni-MH AAA 1000mAh Rechargeable Battery w/Tabs

Psion 5MX

The Psion 5MX and the Erickson MC 218, both had broken display cables, which is a common failure for Psion 5MX devices. I was able to order some replacement cables from Psionex. Nick and Rudy at Psionex were real helpful when I contacted them to verify that the Erikson MC 218 used the same screen cables as the Psion 5MX. I was surprised at how quickly they responded. It was late on this side of the pond so I did not expect a response from anyone until the next day but within an hour or two from submitting the contact request form, they got back to me.

Once again, David Savery had a post that was a big help. The post from 2004 is titled, Psion Series 5MX disassembly and screen cable repair.

The Psion 5MX that I received from eBay was in rough shape but I powered it on and I found that it had an issue with the screen cable, just like the Ericson. Since it was in the worst shape, I decided to disassemble it first as a practice run.

All went well and I was able to take the unit apart and replace the cable. I did find that it was easier to cut the ribbon cable to separate the touch screen controller before attempting to unsolder the cable. I thought using my hot air soldering station would be quicker but right away, I saw it melted some of the tape and other things around the screen so I just used my soldering iron. It was not too bad to remove and solder the new cable in place.

Fortunately, I was so concerned that things did not go well that I connected everything on the bench before reassembling the unit. I found that even though I measured the resistance on the touch screen connection, something was not right. The screen was spot on though so I was happy about that. It was a bit tricky but I was able to reflow the solder on the touch sensor connections and when I tested again, everything was in working order.

I started reassembling the unit and thought that the hinges seemed to be off, but I could not determine what the problem was. When it was finally all reassembled, the wire hinges popped out from under the rear cover. I then went back to Dave Savery’s page and finally saw that there were supposed to be hooks to keep them in place. I had to think of something so I used some leads from resistors that I had saved and melted them into the plastic and formed some hooks to keep the hinges in place. Hopefully that is enough to keep them in place as long as I use it. We shall see but it looks fine for now.

Photo with the hinge hook circled — One of the hooks that were missing on my unit.

Broken Ericson MC218 and the repaired Psion 5MX — On the left is the defective Ericsson MC 218 and on the right is the repaired Psion 5MX.

The repaired Psion 5MX is now my spare unit as the hinge repair job is not perfect. There is now some play in the unit so it does not close tightly. The keyboard and screen flop around by about 1/8″ (3 mm).

Below is a link to the Cables on Psionex. I’m not certain how much longer they will be in stock, but I will be reaching out to them again if I’m in need of any more. I’m including the link to the Series 5 cable as well.