• Please review our updated Terms and Rules here

Toshiba T1000LE not booting up

rzmijan said:
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:
www.ebay.com

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 :)
Click to expand...
hi, how did you track down the actual part number knowing only the case markings?
thanks!
 
compaqportableplus said:
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.
Click to expand...

I just wanted to give more visibility to this message. After trying to repair a toshiba T2000 twice (I bought two units) and also discussing with people repairing T1200 or the likes, I have to confirm that these units are to be avoided for retro enthusiasts.
Something is simply wrong with the power supply, and it's not the caps, I suppose some surface mounted mosfets , or even the power supply controller itself (as there are a plcc "brain" on these psu) simply doesn't cut it after 30 years. Even if you're lucky enough to find a unit that boots, it'll die after less than an hour of use.

They are impossible to repair, at best they behave erratically until they eventually die for no reason. Parts are often surface mounted and unlabeled.
I am giving up on repairing the "T2000 era laptops", and recommend you all do so.
 
Dokken said:
I picked up a T1000 in a FB buy last week (also a TRS-80 Model 100). The T1000 power section caps were very leaky but no noticeable corrosion. got the caps replaced and a temporary battery solution and it boots up! The working battery connection is required. the barrel DC port does not power the laptop without a working battery connected to the mobo. I guess the external 9v is for charging.

The LCD screen is in bad shape but viewable. it looks like it is de-laminating or something? are there modern options for replacing the display?


View attachment 1250660
Click to expand...
Hi,

It's a late reply but anyways since I've picked up my T1000 a week or so ago I can say "yes" to your findings. I've also recapped electrolytes, managed to buy new 4pcs of 1.2V NiCd cells, replaced the 9V DC socket, (mine was badly corroded) and the machine booted right away.

As for the damaged screen you have posted a picture of, I'm not sure but it might be the top layer of the polarising film. The twisted nematic, i.e. TN LCD is sandwitched between two such polarising sheets rotated 90 deg. with respect to each other. I think these can be bought (ebay, aliexpress to name a couple) and cut to desired size if you wish to replace yours. That would require dismantling your LCD panel of course.
 
I thought I would give an update on some progress I had with my T1000's so far.
To date I have amassed two T1000LE's, one T1000SE, two T1000's, two T1200's, and one T1600.

Repairs attempted so far were on the T1000LE's and on one T1000 - all successful, both LE's are up and running any time, all the time. I've managed to gently open their battery packs, replace the cells and seal it back.
A lot of work and attention to details is what made it possible I think.
- Recap tantalum and electrolytes using high quality low ESR electrolytes for replacement
- bad tantalums do not only fail by exploding, they may also leak a DC current through and you won't notice it if the current is small enough not to cause them to explode.
- Check MOSFETs and SMD elements around the power supply section on both sides of the mainboard
- inspect the board for broken/corroded traces, cracked SMD elements, etc., in some cases you have to desolder some smd chips and other elements to inspect the traces underneath these bits.
- clean/wash the board in plenty of isopropyl or a PCB cleaner.

I am looking at the T1000SE as the next candidate for resurrection. Will let you know how it went.
 
You must log in or register to reply here.
Back
Top