Toshiba T1000LE not booting up

[Zythen]

I bought a second hand Toshiba T1000LE (not working of course) and I am having trouble fixing it. It came with a working DC charger and when plugging it in and trying turning it on did this:

Just some quick light blink and a noise from the floppy drive that it is trying to do something.

The problem is that i won't turn on so after a bunch searching later I had found a post on this forum recommending replacing the, on my machine, very leaky electrolytic capacitors.

So I had went out and bought Panasonic replacements for all the capacitors on the motherboard and on the power circuit.

2X 10V 220uf
2x 25V 120uf
2X 35V 220uf
1X 6.3V 1000uf
4X 25v 220uf

But now after replacing all the caps and very thoroughly cleaning the motherboard the only thing working again is the battery charging but still the laptop is still not turning on.
The battery charges a little but being ~30 years old at this point i didn't have hope for it but it does hold a little bit of charge.
The CMOS/RTC battery on the motherboard is at a whole 0.4 volts so that needs replacing but i don't know if that is preventing it from turning on.

Adding a different 7.2 volt power source to the battery pins did not make a difference but it should power on without a battery installed.

There are no visual damages to components that i can see that would indicate them not working.
After cleaning the motherboard i found some sketchy traces that looked broken but i measured all the questionable traces and they all still worked, could still have missed something.

After replacing the caps I was checking the voltages on the points on the images on this comment, I have attached my voltages in this post as well as pictures of both sides of 1 side of the motherboard.
now my voltages are really different at some points so that would explain why its not working properly but i have no idea where those voltages come from or why they are wrong.

Now I am at a loss, the laptop is still not working and I don't know where and how to continue troubleshooting so here I am asking for your help.

Thanks in advance.

 

[modem7]

Welcome to these forums.

I see that the 'DC IN' light is flashing.
That is covered on page 2-8 (PDF page 14) of the T1000LE Maintenance Manual, found at [here].
A snippet from that is:

 

[Zythen]

Thanks for the reply.

I have checked the voltage from the AC Adapter and it is 12 volt but with some infrequent voltage dips to les then 8 volt which might be a problem.

the manual then suggests checking the battery charge circuits so I am going to try and check some voltages and cables to see if the problems is in the PSU circuit or the power circuitry on the motherboard.
Do you by any change have some data to know what voltages has to come from which pins on the battery charge circuits?

 

[compaqportableplus]

Not trying to be a downer, but this issue is why I gave up on Toshiba laptops of this era and recommend against buying them. Replacing the caps almost never fixes them. There's some other issue going on that I've never found.

I really hope you can narrow down the issue though, and I wish you luck. These are really cool machines otherwise.

If you want a more reliable Toshiba from that era, go for one of the dark gray AC-powered units with gas plasma displays. They are solid machines.

 

[Zythen]

Yeah it seems that every Toshiba laptop of that era is broken in some way and fixing them can be a bit tedious.
I will try and fix it but if i give up the laptop is going to become a cool retro Raspberry pi based machine.

 

[rzmijan]

Hi, I'm new to the forum. This is my first post here and I have just bought the T1000LE. After changing all the electrolytic caps having the exact same problem, i.e. flashing DC-IN followed by a quick flash of the other leds. I have still not given up on this and will definitely post back my findings if I manage to bring it back to life.

 

[nullvalue]

Hi, I'm new to the forum. This is my first post here and I have just bought the T1000LE. After changing all the electrolytic caps having the exact same problem, i.e. flashing DC-IN followed by a quick flash of the other leds. I have still not given up on this and will definitely post back my findings if I manage to bring it back to life.

I have a T1000LE with this exact same issue. LED blinks, when I press the power button all the lights come on for a brief moment, then it shuts down immediately. I know you only posted this a couple weeks ago, but any luck?

 

[rzmijan]

I know you only posted this a couple weeks ago, but any luck?

I'm suspecting an smd voltage regulator on the flip side of the mainboard. It was a nightmare to identify what that smd is by its symbols - this alone took me about two weeks, but finally I have nailed it. It's on order via eBay from China at the moment, still a couple of more weeks before I get it I'm afraid. I'll definitely respond here, even if negative result.

 

[nullvalue]

I'm suspecting an smd voltage regulator on the flip side of the mainboard. It was a nightmare to identify what that smd is by its symbols - this alone took me about two weeks, but finally I have nailed it. It's on order via eBay from China at the moment, still a couple of more weeks before I get it I'm afraid. I'll definitely respond here, even if negative result.

Awesome, thank you!

 

[rzmijan]

The CMOS/RTC battery on the motherboard is at a whole 0.4 volts so that needs replacing but i don't know if that is preventing it from turning on.

Yes, it may prevent from turning on, cause the blinking LEDs including other weird behaviors such as unexpected shutdowns/power loss. Make sure you connect a FULLY charged cmos/rtc battery. If this does not help then you're certain the problem is elsewhere.

 

[rzmijan]

Yes, it may prevent from turning on, cause the blinking LEDs including other weird behaviors such as unexpected shutdowns/power loss. Make sure you connect a FULLY charged cmos/rtc battery. If this does not help then you're certain the problem is elsewhere.

OK, I take it back. Actually I've run into some issues which on the surface look like cmos/rtc related and I may have falsely associated it with the laptop not being able to turn on. After more testing I do not have a proof that actually connecting a healthy cmos battery or disconnecting it makes any difference - in either way it does not power on.
I'll keep you updated.

 

[rzmijan]

Awesome, thank you!

I've found a shot SMD voltage regulator. Description below, including the location on the flip side of the mainboard. Make sure yours has the RD imprint on top.
Ordered here:

5PCS S-81250HG-RD-T1 SOT-89 | eBay

Find many great new & used options and get the best deals for 5PCS S-81250HG-RD-T1 SOT-89 at the best online prices at eBay! Free shipping for many products!

www.ebay.com

what matters is the upper RD symbol, the bottom one is LOT number (my was R5, but yours may be different).

The good news is that the laptop started, booted properly from the old hard drive, and worked for about a day. Then it started switching off suddenly. After a few more on/off cycles it would not want to turn on any more. The red DC-IN stays on, not flashing, but it will not power up anyways. More testing and troubleshooting on the way when i find more time.

I can definitely confirm that you do not need a battery to switch it on - it should power up and boot on the power supply/charger alone.

Let me know if you also find this SMD part broken on yours, and of course if you manage to bring your toshiba back to life, even if for a day

 

[nullvalue]

Let me know if you also find this SMD part broken on yours, and of course if you manage to bring your toshiba back to life, even if for a day

I haven't cracked mine open yet but will take a look - I'm guessing by a brief lookup on that datasheet that the expected output is 5V?

 

[rzmijan]

I haven't cracked mine open yet but will take a look - I'm guessing by a brief lookup on that datasheet that the expected output is 5V?

Yeah, I think so, for clarity I'm attaching my datasheet. I'm sure that mine was dead - if you take a good one and set your multimeter to the diode tester, and check between pins 1-2 (input) it should read about 0.6V, mine was showing an infinity, and when set on resistance it was in mega ohm range. Definitely was not good.

 

[rzmijan]

By the way, I'm also suspecting the oscillator ticking the RTC chip, or the chip itself may be faulty. Need to run more tests, but don't have much time at the moment...

 

[nullvalue]

OH man.. I've got a bit of a horror show going on here.

Immediately after opening I noticed I had a component with a black spot on it, and upon closer inspection it looks like it's case is even cracked.


Everything in this area is just caked in what I'm assuming here is cap juice.


Gah!! the back side is even worse..


Needless to say I haven't bothered to test any of these components until I get this board cleaned up.. At a minimum I'm guessing all these electrolytic caps need to be replaced.

 

[rzmijan]

OH man.. I've got a bit of a horror show going on here.

Immediately after opening I noticed I had a component with a black spot on it, and upon closer inspection it looks like it's case is even cracked.
View attachment 1246847

Everything in this area is just caked in what I'm assuming here is cap juice.
View attachment 1246848

Gah!! the back side is even worse..
View attachment 1246849
At a minimum I'm guessing all these electrolytic caps need to be replaced.

yes, not only these, but change the electrolytic ones ALL over the mainboard - no exception. Even if they look good and /or measure the right capacitance do not get tempted to leave them on. They pose a huge risk - bin it. There's no way even the best of this world electrolytic cap can survive over 30 years without loosing it's parameters, especially if it was not powered on for ages.

 

[rzmijan]

OH man.. I've got a bit of a horror show going on here.

Immediately after opening I noticed I had a component with a black spot on it, and upon closer inspection it looks like it's case is even cracked.
View attachment 1246847

Everything in this area is just caked in what I'm assuming here is cap juice.
View attachment 1246848

Gah!! the back side is even worse..
View attachment 1246849

Needless to say I haven't bothered to test any of these components until I get this board cleaned up.. At a minimum I'm guessing all these electrolytic caps need to be replaced.

Q502 - That's a P channel MOSFET. May be difficult to find a replacement. I bet these are not manufactured for a long time, so best to download its datasheet, note the key parameters and start looking for a replacement. I think I've already seen somewhere someone reporting these (Q502) blow up on T1000s.
Desoldering these rusty caps is a nightmare. I used a good amount of flux, added fresh solder on top and then a desoldering gun did the job.
Good luck! And keep posting the progress.

 

[rzmijan]

Needless to say I haven't bothered to test any of these components until I get this board cleaned up.. At a minimum I'm guessing all these electrolytic caps need to be replaced.

Ah, do not forget you also have a few more electrolytic caps on the separate power inverter / LED board sitting under the LCD panel. On mine these looked clean and a couple even measured about the right capacitance, slightly high(ish) ESR, but... for me these found their new home in the bin. I'd rather not play a lottery.

 

[rzmijan]

View attachment 1246848

Here you go, our Q502:

2SJ182 FET Datasheet pdf - MOS FET. Equivalent, Catalog

Hitachi Semiconductor 2SJ182 | FET. ( DataSheet : www.DataSheet4U.com ) 2SJ181(L), 2SJ181(S) Silicon P-Channel MOS FET Application Hig.

datasheetspdf.com