Toshiba 110cs Rip...

[3lectr1c]

If it's purple, it's a polymer.

 

[GiGaBiTe]

If it's a Sanyo polymer, it needs to go. Those things turn into resistors.

 

[Wappynutter]

Thanks for the input, and yes, hiding in that little case was indeed a crusty legged electrolytic.
How did I miss that yet replace the one on the other end of the board?


...and after a gentle poke to detach the glue underneath is... crusty too..


Off with it and a quick clean up..

Unfortunately I only had a 6.8uf 35v tantalum cap to replace it with. Hope that'll do.

The removed cap read 1.2uf in circuit and 6uf off the board. The tantalum was a healthy 6.9uf.
Back on the bench, power, diagnostic card and... Well of course its still the same.
I'm beginning to suspect that 187hp or keyboard connector is halting the boot.
Maybe I should replace those warm resistors too? Or maybe those other warming parts in the power area.

Looks like one of the coils, a diode and transistor. Unsure without checking the board markings.


Just clutching at straws with this old Toshiba.
Thanks again for all the input and suggestions everyone, appreciated.

 

[GiGaBiTe]

D511 (1BL3 Schottky Rectifier) in the second to last pic looks sus, like one side of it isn't properly soldered.

With all of the cap leakage, I'm suspecting that you may have dead parts from cap electrolyte getting inside them, as well as broken traces under chips. I'd just keep measuring stuff and see if it doesn't match what the thing says it is.

It's clear that something is drawing current with the buck regulation circuitry getting warm. Since it's not getting smoking hot, I don't think there's a shorted part, just think either components are out of spec or there's broken traces.

 

[3lectr1c]

If it's a Sanyo polymer, it needs to go. Those things turn into resistors.

Ah interesting, didn't know that. Might be worth trying to replace those on my WinBook XP5 to rule them out as a problem.

 

[GiGaBiTe]

Ah interesting, didn't know that. Might be worth trying to replace those on my WinBook XP5 to rule them out as a problem.

I used to think old polymers were fine, that was until I started coming across those purple Sanyo polymers. Every single one of them I've tested have been bad, dozens and dozens of them. They never leak, but they most commonly turn into resistors or lose a massive amount of capacitance. Like 50% or more capacitance loss from spec.

Then of course there are the fake tantalums, those things are always hideously bad.

 

[3lectr1c]

I figured the purple fake tantalums would be polymer, not electrolytics? All I see in the photos above looks like dried glue and flex residue, no electrolyte. Well noted though that they likely need replacement.

 

[Wappynutter]

So I've reflowed the big chips and converters as suggested and checked out the warming parts in the power area. The inductor coil has some corrosion/flux so may need a reflow too. After part checking I can see that maybe the voltage regulator should be warming, after all its taking 5volts and outputting 3volts...or should be.
Unsure why the transistor labelled MY is warming beside the power switch.


So I'm wondering and thinking I need some help identifying power rails and what's switching where.

I'm guessing 3 inductors, 3 power rails, 1 main 18volt in, 1 battery in, 1 charging circuit?
Again just wondering but if I connect bench psu to battery pins to replicate battery power, no mains voltage in. Will I get a different result, coil, voltage regulator, transistor heat up? Will it use a different route to supply power?
Anybody know what battery volts and amps are and battery connector pin layout?
Just pondering my next move to isolate the problem area.
All input welcome and greatly appreciated.

# quick check, it seems to be a 10.8v pack. Just need to get poking around with the multimeter to find ground and positive pins#

 

[GiGaBiTe]

If you haven't already, I'd suggest taking the "101 KS" black inductor off and checking under it. I've seen those things wick electrolyte inside them and corrode the wires off one or both sides, or corrode them to make them high resistance and make the inductor not work.

You may also want to wash that area of the board again and scrub it with soap and a tooth brush. It still looks like there's a lot of residue in that area.

As for trying the battery pins, you can, just make sure you don't get anything backwards or exciting times will be upon you. It may not work, because later battery packs had smarts in them that send signals to the power circuitry to monitor the health/temperature of the battery. You can always try though.

 

[hunterjwizzard]

Oof. I guess I'm opening up my gateway tomorrow to check for a varta.

 

[Wappynutter]

Hope that Gateway is safe and sound.. Good luck.
Hey GiGaBiTe..... think I made some progress but won't know until over the weekend and it's your suggestion that put me in the right area to discover a hidden problem. I gotta check it out but hey, thanks for the input.
So anyway you suggested that Tolkin coil thing may have failed and it needed a check and clean.

This one I removed off my dead 110cs to transplant over if the 210's was dead.
So anyway I read the "clean the board" comment and decided to use the ipa and a good brush.
Cleaning away I got to here.
Realised I couldn't clean around and between the regulators or whatever they are here. 4 larger, 2 smaller. So I parted them and spied a potential problem.

That looks like a massive hidden explosion and burn. I haven't had a chance to test with the multimeter or get the soldering Iron out to remove it and get a closer look incase it's just glue or something but I'm sure I spied splatter on the board needing a clean.
Now unfortunately family commitments meant I couldn't stay and investigate but tomorrow I'm on it. Maybe I've found the problem, maybe it's just another red herring. This Toshiba has lead me a dance this far, I gotta strike a win sooner or later.
Wish me luck, drop any thoughts or input on what I've discovered thus far.
More soon. Thanks again for the suggestion GiGaBiTe, appreciated.

 

[3lectr1c]

That sure looks blown up to me.

 

[GiGaBiTe]

That was actually not the inductor I was talking about, but at least it lead to a problem being found lmao.

If one of those is blown up, the others are probably not in good shape either. I'd carefully check all of those mosfets/transistors, and if they are giving weird readings, replace them.

The MM1089 chip next to them may or may not be related, that's the NiCD battery charger control chip.

 

[Wappynutter]

So, back on this 210cs. Out with the soldering Iron and removed.

Clean the board and back of the other nearby ic.

I was unsure of the multimeter results so just swapped out the same chip removed from a 110 board destroyed by Varta.

Soldered in and checked..

... and plug in the diagnostic card, power and thermal camera in hand and guess what??...

No change.... same results, card results power up activity.
Guess I'm testing up and down stream from the J377 to see if it's damaged other components.
Why??... it just taunts me..
Oh well, more soon..

 

[GiGaBiTe]

Did you check the other black inductor next to the toroidal coils?

 

[Wappynutter]

Ha.. yeah gotta pull that one too as I spy some orange discolouration under it. I'm reading mega and k ohms when I use the multimeter.
Unless I'm testing wrong. I'm a novice tinkerer, I can follow testing instruction and check for what I should have based on schematics and such but I have no clue what I should be reading on this machine apart from the obvious or part number data sheets. Electronics were never my strong subject, I have to tinker to try and keep them functional without making magic smoke .. haven't done that it 40 years intentionally but there is a chance with this thing. Lol..

 

[Wappynutter]

Just here look..

 

[Wappynutter]

So put that damaged inductor in the cheap tester...

It's a capacitor now.. lol..
Tester one I pulled off the dead 110cs.

Looking about right, not sure on the readings but seems to be identified correctly.
...and now I'm getting a 3rd warming resistor..

That 471 below the G12 ic. Reads damn close to expected resistance so the 20c isn't doing it any harm. Yet......
So now I'm getting 3 warming resistors on the rear of the power/charging area..
That 471 comes off a leg on the chip then goes back through the board.. I'll trace it more tomorrow.
More fumbling blindly soon... lol..

 

[Wappynutter]

So while waiting on a delivery from the other side of the world for some parts for the IBM and a slightly better oscilloscope I dug the 210cs out of its box.
Thinking I might be missing voltages to the cpu and ram causing the "ff" code on the diagnostic tester. Apparently "ff" can mean either fault found or a serious problem with cpu or ram, which worries me.
I found the cpu type and a pin out.

Lifted the cover etc.. to uncover the pins.
Checked the power pins on the testpads and via's and power management ic's and yes.. 3.1 to 3.3 volts on vcc2 and vcc3 pins.
...but there was a discovery that I gently removed with a cotton bud but bent a pin.
I found a green blue corrosion spot on a pin.

Note bent pin 285..


Under the microscope you can still see a faint green blue mark but the pins are tissue thin and I dare not touch it anymore. I believe it is still attached just dinted in were weakened. Pin 285 is a byte enable pin BE0#. So hopefully still good.
So continued checking volts and voltage regulators.. Ram power, all good and receiving 3.3 volts on the power legs to every chip.

Now next to those are the battery connector pin vias and the vias I had to repair due to corrosion. Now these vias were really gummed up and damaged with no continuity through the board.
My repairs are real rough but I get Continuity now...

Top side here I have 4 vias on the white line to the left of the removed battery connector vias. These 4 pins come off the Toshiba 187 chip..

..and top side I get 5 volts on each via.
Bottom side of the board these vias I expected 5 volts but 1 via only reads 1.8 volts max. These vias connect to the Toshiba Peggy3 chip.

So I'm losing 3 volts to one of the pins on the Peggy chip. Maybe I should rewire, reflow or run another bodge wire through this via. Connectivity is a little patchy on that via but when I check with the thermal camera it doesn't get warm there indicating a short internally.
Could this lack of voltage cause the boot halt, "ff" error and no screen or audio beeps?
As stated earlier i was expecting no voltage to the cpu or ram but both have the expected voltage present. The 187 chip controls the keyboard I think and both internal or external keyboard connectors don't work. Maybe it's halting on a keyboard error?
What does the forum think? Am I on to something or just chasing a lost cause?
Any advice appreciated. If anyone has a 210cs or 430 to test via voltages in this area I'd be grateful. Thanks again, more soon.

 

[Wappynutter]

So I removed the board, reflowed the via's making sure I had good continuity. Upon testing I have a good solid 5 volts both sides of the board at the via's.
Connected my diagnostic card in the lpt port and powered up a couple of times. Seems I no longer have a "ff" error code. Yay!... but I do still have codes, "00" and "01". These codes are not the best codes to be seeing or halting at.
Tomorrow I'll connect the screen, sound card etc.. and power up, see if I get anything.