Toshiba T1100 Plus - New Owner Questions

[desertrout]

I've acquired a T1100 Plus but have never owned a machine like this before (my collection has been exclusively Apple machines until now). I'm wondering what 'first things' I need to know before doing a first boot and other items to be aware of as an owner and user.

For instance:
- the machine is not coming with an adapter; I know it needs to be 9V/1.1A, but what size is the barrel, and is it center positive?
- does the internal battery need to be functioning / connected in order to boot the machine (or safely boot)? If the battery needs to be rebuilt, does it need to use NiCd cells?
- are there known issues with caps, either on the display, inverter board, or logic board?

I'm currently flipping through the owner's manual and the maintenance manual, but I'd love to hear from those who have experience using and repairing these machines in more recent years. Thanks!

 

[Plasma]

Center positive but I don't know the size. Hopefully it still powers on because the internal power supplies on those early Toshiba laptops were crap. Batteries are not required to operate.

 

[modem7]

does the internal battery need to be functioning / connected in order to boot the machine (or safely boot)?

Batteries are not required to operate.

Is that a known/established fact about the T1100 PLUS, or a generalisation?

I ask because the T1100 PLUS' predecessor, the T1100, something I own, cannot operate if the battery pack is bad, or if the battery pack is simply removed.
And on a later model, the T1000, the web page at [here] contains, "Note that this computer does not work without a working battery present (or other DC power source plugged directly into the battery terminals)".

 

[Plasma]

Based on my experience with the T1200XE. I don't know about the T1100 PLUS specifically.

 

[modem7]

does the internal battery need to be functioning / connected in order to boot the machine (or safely boot)?

To my surprise, in the appendices of the technical manual for the T1100 PLUS, are some circuit diagrams.
The circuit diagram of the power supply board indicates that if the battery pack is simply unplugged, the T1100 PLUS will not power on (unplugging breaks the circuit between CR5/CR6 and part of S1, S1 presumably the power switch).

(For testing purposes, a +5V power supply could be used in place of the battery pack, if done properly.)

If the battery needs to be rebuilt, does it need to use NiCd cells?

You can use NiMH, but there are disadvantages. See [here] for some details.

 

[modem7]

the machine is not coming with an adapter; I know it needs to be 9V/1.1A

What Toshiba supplied is pictured in the 'AC adapters' section of [here].
The "1.1A" means that the most current that the adapter is designed to supply is 1.1 amps.

So, does that mean that you can simply use a +9V DC adapter that is capable of supplying more current (even though that additional current won't be called upon) ?
First, be aware of unregulated versus regulated - see the diagram at [here].
I do not know whether the adapter supplied by Toshiba is unregulated or regulated (Toshiba T1100 PLUS technical documentation does not inform me).

If what was supplied by Toshiba is regulated, then the answer to the question is, yes.

If what was supplied is unregulated, then the questions become:
- There are different degrees of 'unregulated'. As a fictional example, maybe the low-load voltage from the Toshiba supplied adapter is about +10V DC; in which case, would damage (or improper operation) result if what was used is a third-party adapter that has low-load voltage of about +12V DC ?
- Is using a regulated +9V DC adapter going to work as a substitute? I.e. Maybe the circuit relies on the fact that the low-load voltage of the Toshiba supplied adapter is significantly more than +9V DC.

Maybe just try a regulated +9V DC adapter that can supply up to 1.1 amps or greater, and see how that works out.

Maybe someone here with a T1100 PLUS has already been down this path.

 

[desertrout]

Thanks for the input, much appreciated!

I do not know whether the adapter supplied by Toshiba is unregulated or regulated (Toshiba T1100 PLUS technical documentation does not inform me).

This is exactly the reason I ask... I have some experience with and knowledge of the Macintosh Portable, which relies on a regulated 7.5V/1.5A adapter -- if you use an adapter that allows the draw of too much current, it can damage the logic circuit (even though it's only supposed to be used to charge the battery). I have a 9V / 1A adapter handy, but it is most certainly unregulated... perhaps I will source a regulated one to be safe.

To my surprise, in the appendices of the technical manual for the T1100 PLUS, are some circuit diagrams.

Interesting. I didn't notice this, I will go look again. Thank you!

You can use NiMH, but there are disadvantages. See [here] for some details.

Funnily enough, as soon as I asked that question I realized it was unnecessary... NiCd cells are easy to come by, won't be an issue to build a new battery...

 

[modem7]

In case you are unaware, there is another battery that is of concern.
See the 'Battery for clock/calender' section of [here].
If what is fitted is the original battery, the battery may have leaked.

 

[desertrout]

Thank you for the reminder - I had noticed that earlier. The machine does boot (albeit with a faint screen - could be for a few different reasons) so at least I know that if there has been some leakage it hasn't caused any fatal damage.

Going through the User's Manual (http://www.minuszerodegrees.net/man...ba T1100 PLUS - User's Manual - PAD8645-1.pdf --- thank you for archiving these), and noticed a 'note' in the troubleshooting section saying that the computer will not start with a discharged battery even if the adapter is connected. So it looks like a bench supply will need to be used until I put a battery together...

 

[Eudimorphodon]

I had an 1100Plus many, many years ago (bought it for nearly nothing at a garage sale in the 1990's), alas long lost to history. When it was "new to me" the battery was good for a couple hours, but after a few years the machine turned into a pumpkin after the battery went completely bad. So I would concur (based on my rusty memory at least) that a dead battery can keep it from running.

 

[modem7]

So it looks like a bench supply will need to be used until I put a battery together...

Wow. Someone at [here] used a USB battery bank as a substitute for the 5V battery pack.

I have some experience with and knowledge of the Macintosh Portable, which relies on a regulated 7.5V/1.5A adapter -- if you use an adapter that allows the draw of too much current, it can damage the logic circuit (even though it's only supposed to be used to charge the battery).

I have never heard of that. Out of curiosity, I will do some research.

 

[modem7]

This is exactly the reason I ask... I have some experience with and knowledge of the Macintosh Portable, which relies on a regulated 7.5V/1.5A adapter -- if you use an adapter that allows the draw of too much current, it can damage the logic circuit (even though it's only supposed to be used to charge the battery). I have a 9V / 1A adapter handy, but it is most certainly unregulated... perhaps I will source a regulated one to be safe.

I have never heard of that. Out of curiosity, I will do some research.

So, explained in part of the video in post #16 at [here].
Due to the design of the Macintosh Portable.

 

[desertrout]

Wow.

I dunno, it's not a big deal and I'm not in a hurry. A USB battery bank is an interesting idea, but honestly remaking the battery is very simple and inexpensive --- and you can then use the machine to charge the battery instead of an external charger. And you also have the benefit (for me anyway) of having a more 'original' machine.

These, or something like them, should do the trick (pre-tabbed, so no spot-welder required) https://www.ebay.com/itm/362518907670 I've repacked quite a few batteries for other machines, as long as you match voltage and stay chemically like-for-like (or at least try to match charge/discharge profiles) it works well.

Due to the design of the Macintosh Portable.

Yep. The power management system is 'badly' designed, or at least the designers made the assumption that users would always and forever use the machine the way they were told in the user manual. Many, many Portables have been bricked because of modern assumptions about how a power management system should work ("it will only draw what it needs" or "it has over-current protection"). Mine was almost added to that bricked list... thankfully only one IC was damaged, and it was replaceable.

So, understandably, I'm gun shy about adapters.

Anyway, I won't be able to pick up the Toshiba for a few weeks. Then we'll see what's what.

 

[silence012]

So, first congratulation for your new machine This is very nice laptop.

First thing you should do is to remove BIOS battery. Hopefully it didn't leak too much.

I always replace all electrolytes, but it is up to you. T1000 Plus does not have many of them, so it will not be big deal.

For internal battery, as it will not power up without it, there is a simple hack that I discovered.
It has 4 wires (2 red and 2 black). Cut the old battery pack and join together two red and two black (two reds is one join and two blacks is second join).

With this, you can use the laptop directly from power supply. As it now relays only on power supply, it will have just enough power so that you can use it. You might notice that LCD looses a little bit contrast when FDD is active but it is not big deal.

You can of course build your battery pack, or even find already built one. I don't know where are you located, but I bought my on this website: https://www.akkushop.de/de/notleuch...200mm-kabel-einseitig-passend-fuer-48-v-akku/

Cheers,
Branko

 

[desertrout]

Thanks @silence012 - I like that direct power tip. I finally brought the machine home today and I discovered it had already been modified to accept drop-in cells, but I already had tabbed NiCd's on hand and made a 5V pack to put in there. I also have a 9V/1.1 adapter with the correct plug. so I'm all set on the power front.

The battery hadn't leaked at all, and cosmetically everything inside looks ok. It has a RAM expansion, which is nice.

However, the machine isn't booting. I get the power LED, and the PSU light comes on when I plug in the adapter, but the CRT LED remains lit, despite pressing Ctrl+Alt+Home, as per the manual. I did connect a composite monitor, but nothing appears on the screen. So, something's up.

At this stage, I'll do a full recap - as you say, there aren't many on the power board and logic board. Are there caps on the display as well?

 

[desertrout]

Answered my own question - 7x 25V 10uF radials, laying flat on the backside of the display panel. All of them were out of spec.

Also discovered the display cable has an intermittent connection - some of the cable insulation has been worn away at the hinge, so I'll need to firm that up. That, and one of the column... connections (? not sure what to call them, the fine pitch terminals along the edge of the display, obviously for the display columns) is corroded open, so that may need to be addressed.

Clock battery did actually leak a wee bit and corroded away the via at its negative through-hole. So, a few things to do.