Wednesday, June 29, 2016

The Toshiba T1000 back to life!


Hi there,

As you know I got a Toshiba T1000 from a friend from Holland about 3 weeks back. I was posting on my Facebook page The x86 Generation that this machine dosen't even power up. That has changed dramatically in the past 3 weeks!!!

Source: PCWORLD.COM

"The Toshiba T1000 was a laptop computer manufactured by the Toshiba Corporation in 1987. It had a similar specification to the IBM PC Convertible, with an 4.77 MHz 80C88 processor, 512 kB of RAM, and a monochrome CGA-compatible LCD. Unlike the Convertible, it includes a standard serial port and parallel port, connectors for an external monitor, and a real-time clock.

Unusually for an IBM compatible PC, the T1000 contained a 256 kB ROM with a copy of MS-DOS 2.11. This acted as a small, read-only hard drive. Alternative operating systems could still be loaded from the floppy drive, or (if present) the ramdisk.

Along with the earlier T1100 and T1200 systems, the Toshiba T1000 was one of the early computers to feature a "laptop" form factor and battery-powered operation."
                                                                                                                                       
                                                                                                                                        from Wikipedia


At the time of its release, circa 1987, critics hailed the Toshiba T1000 as a groundbreaking innovation. It was the lightest PC-compatible laptop ever released up to that point, and the press considered it the MacBook Air of its day.

Like the MacBook Air, the T1000 shipped with a solid state disk: It packed MS-DOS 2.11 on a built-in ROM chip so it would be available instantly when powered on. For $549 more, you could increase the RAM to 768K, and use a portion of that memory as an ultra-fast RAM disk that retained its data as long as the main system battery didn’t discharge.


T1000 : Disassembly, Day 1, cleaning the motherboard against the electrolyte from the caps and battery spill 

Dissembling the unit is an very easy job as all you need is to unscrew 6 bolts and pick up the upper casing. Anyway, as for some this could be a challenge you can download the USER MANUAL here.



After removing the screws gently put the display in Open Position and then just unclick the top from the bottom. After that remove the video cable and let the fun begin.


After doing so you get this:


 The next step is to unscrew the keyboard bolts, remove the battery, then the FDD drive bolts and finally you get to the Motherboard.


 How all you need is to remove the motherboard in order to clean it from that spilled acid. Why? Because that fluid is conductive and thats not good for the sensible components.



 If you look in the next images you will see the acid laying on the motherboard.


I had cleaned the motherboard using isopropyl alcohol and nicely spreading it with a paint brush.



 After doing so I let the motherboard dry under a 25W Lamp (not neon)

           

As electronics age, the second components to fail (after batteries) are usually electrolytic capacitors, which break down over time and either deform or leak.

The next step was to check if the caps are dead or not. I tested them with a multi meter and could see a linear discharge so they seem OK but as they were leaking I decided to put new caps. Lucky for me I had a T1200XE dead unit that had good caps. I don`t want to use new caps, as they are very poorly made.


VR2 and PJ23

The next step is to get this machine to its initial parameters. otherwise it won`t boot. 

  • Assemble your computer back, except for the display and FDD unit (you will have more space to operate).
  • Ensure you have a 9V, 1.1 Amps adapter plugged in.
  • Use a multimeter to confirm that the output voltages for the PJ 23 on the system PCB conform to the values given in the following table.
  • If the voltage conforms to the values given in the table, try changing the Batteries (4X1.2V).
  • If the voltage does not conform to that given in the table, adjust the VR2 on the system PCB by a Phillips screwdriver. 



As seen below i had used some wiring to adapt to PJ23 the Multimeter
Multimeter on PJ 23

The next step is to use Philips screwdriver to set the value of the multimeter to 2.18-2.19Vdc.


Important! Check if battery is dead or it still holds some juice!

If battery is dead: Change the battery pack or ensure you have a 6V Vdc on the battery pins.

If battery still holds some power, even for a few seconds you can still use it to start your machine.

In my case the battery pack seemed fine so I gave it a try....


AAAAAAND.................YESSSS!!!!! THE MACHINE IS ALIVE!!!!!!!!!

WHO HOO!!!!!!..................................................................................
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...........!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Counting RAM to 768KB

MS-DOS, baby!!! (present on the ROM so no disk required)
C:\>DIR

:))))))

ALIVE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

5

4

3

2

1

DEAD!  :(

...............................................

NOT TO DESPAIR! :)

...the machine just powered OFF... It looks like the Battery pack has died for good, so now I am looking for a drilling machine 6Vdc battery pack in order to use the cells to get this thing working again.

So for all there users that can`t get this machine running... just make sure you have 6VDC on the Motherboard, 9V, 1.1 Amps as supply, clean the motherboard very good, adjust the voltage using a multimeter and BOOT your lost love once again!

THE END..... for now!



1 comment:

  1. Bogdan, it's so amazing what you did.. You made the old machine to live again!! It's so good to see it shining again...

    And great article you wrote, thank you.

    ReplyDelete