CitroJim wrote: 02 Jan 2021, 09:34
Spheres and the timing belt job on the Activa can be done at CitroJim Towers when conditions allow Zel
Yep, really just waiting for vaccines to be distributed (given my phobia of needles, not looking forward to it one bit but needs must) and things settling down a bit.
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We had the first actual not immediately explainable 3D print failure today. This was going fine, right up to point where the printer decided that it would be a wonderful idea to jump to Z=0 - which would be fine if there wasn't about 40% of a model in the way.
No idea why that happened. Guessing there was something awry in the G-code, so I went back to the model and rebuild it, tweaking a couple of settings I'd forgotten to save the previous time.
Moved the printer across to the other side of the room too. Firstly so it's not in the way of the paper tray on the normal printer, but secondly to keep it clear of the window. Having a draught over it sounds like a recipe for warping that does.
It's off on attempt 3 of this model now. The first failure was due to a failure of build plate adhesion, which was brought to my attention when I heard a clonk, followed immediately by the half finished model rolling across my desk after it was punted out of the printer by the extruder.
If we get through the next hour without it going haywire again we might be in business this time.
Main job for this afternoon was a quick one but something that's been on the to do list since 2005. Well, kinda. Sorting out the very, very dead NVRAM batteries in my old Toshiba laptops.
They use lithium thionyl chloride batteries for the NVRAM backup so they very, very rarely cause issues with leakage. However after 20+ years they're generally utterly dead. The T5200 has had this issue since 2005 meaning I need to reset the clock every time I start it up. However it's been the T3100e I've been using a bit more lately as it's more portable. So it's the one I'm sorting first.
This is the error I get every time it's powered up. Sorry for the image quality, plasma screens and digital cameras are not good bedfellows.
Followed by:
Step 1 is to flip the machine over and remove the three screws under the keyboard front edge.
You can then release the two little clips that are hidden in the screen catch recess.
This allows the keyboard to be lifted up and laid down in front of the computer. The ribbon cable is exactly the right length for this.
Two further screws need to come out at the rear of the keyboard recess then the RF shield can be withdrawn.
You can then get to the keyboard connector. You don't *need* to remove the keyboard, it just makes things easier though as it gets in the way otherwise. This has one of those connectors with a raised collar you have to pull out before you can remove the ribbon cable.
There we go, access to the area we need. If I had a memory upgrade to go in this is where it would be done. Sadly the T3100e uses proprietary memory so I can't just stick any old 36 pin memory in. If I had an 80287 math co-processor it would be fitted to the empty socket roughly central towards the rear.
Here's our target.
The trickiest bit of this process to be honest is getting the power connector off the motherboard as there's very little clearance beneath one of the case retaining lugs.
Still only about a 2/10 though, just a bit fiddly.
The battery holder itself is held in place by a bit of velcro.
While the battery is a standard AA in terms of form factor a bit more work is needed than dropping a new one in, as the connections to the original are spot welded on.
The eagle eyed among you might have spotted there's a tiny little diode in there too. I think that's a holdover from an earlier design which used a NiCd battery and had charging hardware on board. Because of the spot welded connections there are no actual terminals in the battery holder.
I figured rather than messing around trying to solder to lithium batteries, for the sake of £0.75 apiece I'd just get a new battery holder with standard connectors in.
I remember when I first got the T5200 that these batteries were really hard to find...however now you can just get a pack of 10 from Amazon or eBay for less than £20.
The T5200, T3200SXC and T1200 will want this job doing as well, hence the larger pack I picked up.
I just snipped the leads off the old battery so I could reuse the connector etc. For a change I did remember to put the heatshrink in place before soldering the wires together!
I bundled up the extra length of cable with a couple of small cable ties. Not pretty but it'll do the job.
Luckily for me the glue on the old velcro rectangle was still sticky so I was able to peel it off and put it on the new battery holder.
Convenient as that's not something I had in stock.
From this point on reassembly is the reverse of disassembly.
New battery holder etc shown in place before putting the covers back on.
Note when the keyboard goes back in that there's a lip at the back so it has to go in at the rear edge first.
On the first startup it will of course still be complaining so you'll need to set the date and time one last time in the BIOS setup screen.
Date correctly set...no Y2K issues here on a machine from 1988!
I do enjoy the ARE YOU REALLY SURE YOU WANT TO DO THAT?!? nature of the confirmation screen it gives you before saving the settings.
Rebooting a few minutes later gave no error messages, and checking the date once we'd booted into DOS...
Yep...it's saved the date settings and the clock seems to be running properly.
Very simple job really but nice to have something that was quite annoying ticked off after several years.
Great to see these old computers still in productive use... 
When I have bloods taken the nurse makes me lie down on the couch, just in case!
