Restoring IBM Thinkpad 230cs

[solidpro]

Just thought I'd report on my work to restore up to 3 x 230cs. I think I might come out with one working example



There are two main issues with this lovely little machine:

1) As it originates in Japan only, almost all the screens have succumed to 'Vinegar Syndrome'. I'm midway through trying to get at least 2 of 3 screens working - luckily the Citizen screen in this unit is very easy to disassemble and only has one polarizing layer - the one on top - so less to remove.

2) There is a board inside which sits next to the power in put and it's refered to as "84G8486 Power Sub-Card with coils and electrolytic capacitors". This is the machine's achillies heel. It has about 7 through-hole electrolytic caps on it and 3 surface mounted ones. At least some of the through hole ones on every board have leaked and caused more issues - the corrosion has begun to eat away at tracks in the PCB and the legs of both the small proprietary connector to the motherboard as well as the legs off the biggest IC on the board have come loose in various places. It took me HOURS trying to work out why a so-called repaired board was working sometimes and not other. Under a microscope legs were moving all over the place. I managed to reflow one and get it working. It's a mess but it works. A second works for about 2 seconds and then the machine shuts off. Suspect one of the transistors in there is shot. I don't know if I have the skills to repair it.

My biggest fear from all this is how many other capacitors are in other 1990s thinkpads of mine slowly devouring the insides.....

[astral]

Gotta check those caps for sure! Lovely work as usual. I’d check anything pre-95 for cap leakage at this point.

[solidpro]

Upon doing some more googling it appears the cause of the corrosion is the horrible green varta hibernation battery that originally sits right under this daughterboard..... although the caps are still a time bomb if you ask me....

That's a random google pic by the way but once I have one completely rebuilt I'll take some pics!

[astral]

ah the standby battery. the real killer in all 90s laptops. those things are the devil

[solidpro]

Spent 3 hours de-vinegaring a working LCD from the 230cs today. Replaced with a new CCFL and all capacitors replaced (15 tiny surface mount caps).

The LCD is now usable but the colour reproduction is terrible due to me not being able to locate a decent pair of polarising filters for these older LCDs.

Once I got it running, tested it on my 'most working' 230cs which booted into W95 and then shut off. Now the thing will only power on for 5 seconds before powering off again. Sigh. The 230cs is probably the most cursed thinkpad I have come across... it just really doesn't want to work. I have 7 now and none of them work! Desperately trying to get one working one so that I can use it as a base to test all the spare parts so I can work out what I need. The DC/DC is the worst bit though.

[yyzkevin]

These machines certainly had serious damage when those bridge batteries failed. I have a few of these it was on my list to look at replacing the screens, but I never got around to it. I have one working new machine that is a DX2, I also have one upgraded cpu with the amd 5x86 chip, I did not do the upgrade.

If i recall correctly, these citizen screens are one digit off from the PC110 display. I am not sure I have seen a working one for sale, seems to be even worst failure rate or more rare than the PC110.

Not that I normally use batteries, but it is nice to have the AA battery holder.

edit: also check this out for some tedious 230cs repair adventures if you have not already come across it: https://twitter.com/TenmaniChan/status/ ... 02466?s=20

[solidpro]

Firstly, is that your boxed 230cs (and does it work!?)

Secondly, that 550BJ in box. I just bought one last week in Japan - same as. Mine is BNIB but I won't get it until late next week so see how bad the plastic has gotten over the years... It's not a *real* thinkpad but a really curious diversion. I have somewhere some other laptop with a printer built in - likely the same machine in a different branding.

The 230cs. I spent another full day on these. I think I might just might end up with 2 working ones and then about 5 machines worth of good and bad parts. The screens are pretty easy (comparitively to some) to de-vinegar but I have no real good polarisation filter to replace with. Every few months I order a bunch of different samples online to see if I can find anything that produces good colour for Citizen or similar screens (mainly Japanese IBM related issues) but never come up with anything.

Just spent a few days restoring 2 more 535 machines which by comparison to the 230cs are a dream. Easy to disassemble and re-assemble, easy-ish boards to remove, decap and recap, seem to have survived the battery timebombs a bit better... The 530 on the other hand.... nightmare!

[yyzkevin]

My 550BJ was brand new in box as well, and for sure it had never been touched. But it was not in good shape, it looks perfect but I could not open it, the screws were just corroded so I placed it back in the box and left it. I have some other parts machines also including working displays but it was too fiddly for me all kinds of random boards, ribbon cables etc I put them all back on the shelf and likely will never get back to it.

the new 230cs, that works no issues amazingly. From time to time there are displays for sale for the 230cs, I know somebody that purchased some and they were refurbished but had correct colors. I purchase one from the seller they only had one left at the time, and when I got it there was a problem with a few horizontal lines but it was otherwise correct colors so it is interesting. Most people selling them, once you pay them they respond saying sorry we don't have one. I stopped doing it after a few times as I was getting hit with exchange loss every time, most the sellers were very dishonest.

[solidpro]

There must have been a warehouse somewhere in Japan with brand new 550BJs in it! I suspect mine is the same because it was all sealed up and I am guessing it's a mess inside. I'm hoping I can do something with it. Looks complex to disassemble though.

The 230cs screens - I found some (expensive) ones in China which I am waiting for. I'm hoping someone out there has had a go at replacing the polarisers so I don't have to. It's a bit of a gamble. Maybe they'll arrive next week. I'm amazed the new one was perfect - could be one of the only ones like that left in the world!

I just restored a 510cs today and had to do the screen. It's only black and white though so the colours are not an issue. Not a nice machine to take apart through - you have to fan it out on it's side and carefully connect things as you go.

It seems almost all 2xx/5xx machines have dodgy DC boards with all the caps on. I am slowly working my way back through all my machines doing the caps. I'm fretting through that although I buy the best quality ones, maybe they'll be leaking in 20 years too. I try to use tanatlums where possible but in many case it isn't...

[astral]

god anything citizen made for laptops seems to be just completely cursed. their belt drive floppy units are a proper nightmare.

[solidpro]

After a lot of time and effort, I decided that the only way to make the 230cs usable is to replace the screen using the least invasive and most invisible upgrade possible.

On the right is a 'fully restored' machine with the original screen de-vinegared, recapped and re-CCFLed - it looks awful. The original screen is an 8" DSTN screen and it just completely rots in every way you can think possible.

On the left is a restored one with a new IPS screen.




Here is the screen close-up:




It wasn't without difficulties. Finding a powerful enough 5v rail inside proved tough. Lots of 4-5v rails to power the IPS screen but nothing providing more than 1.1a. I managed to find 2 wires on the 5v rail to power the screen internally, although on a different motherboard, the same source wasn't providing enough amps and had to go back into storage. Seems hit and miss.

The other issue is the trackpoint. Nearly all have failed. I can't quite figure out if it's the motherboard or the trackpoint itself that has the problem. Is uses the visually-same 5/6 wire ribbon most trackpoints use of this era. I tried other trackpoints from other keyboards and couldn't get anything to work. I de-oxed the connector and cleaned it. I shorted some of the pins on the connector and the mouse did move up and down but not side to side. So could actually be both the motherboard AND the trackpoint have failed. Luckily there is a PS/2 port so I use a period-correct PS/2 mouse.

[solidpro]

Oh, and I'm going to do a second one with some very minor improvements, using the knowledge of doing this first one. The only irreversible change I have to make is one 5mm hole in the back of the plastic to feed out the video cable.

When I do it, I'll take pics of the insides / process.

cheers

[ahmadexp]

Any chance you shed more light on the IPS screen you used to replace the original one.
Also, is there any chance someone can share a picture from a fixed power subsystem board. I have a 230Cs that is dead and I am trying to fix it.

[panips]

Any chance you shed more light on the IPS screen you used to replace the original one.
Also, is there any chance someone can share a picture from a fixed power subsystem board. I have a 230Cs that is dead and I am trying to fix it.

I was thinking it could be some vga output alternatives, for a full solution is way too heavy. I also asked a seller from China and got some hints, which suggest the hdmi-ips solution with a hdmi-vga converter.
So I ordered an 8" ips lcd with driver board from him. Also the vga/hdmi converter is easy to get. Both boards look small enough to fit in 230Cs, but a new bezel needs to be 3d-printed.
I'll give it a try when I get them.

It's painful to disassemble a 230Cs...let me see if I got time to take some pictures for you.

[astral]

I think I remember seeing a reddit post from solidpro that showed what he did - it's routed through the VGA port, there was a cable sticking out of the port that ran inside the machine. In theory, you could probably directly wire to the pins of the VGA port internally at the motherboard instead.

[solidpro]

Yeah, sorry, if you measure the 230cs screen for me, I'll look back over my aliexpress order history and look for the one which matches. As I recall it went in ok, but I likely had to desolder any connector that was taking up too much height. I then used some of the many 5 or 12v rails going to the original screen and combined them to make one with another amps to power it and so it was all self-contained except for the SVGA connector popping out of the back of the lid and into the SVGA port. I may have also had to desolder the actual VGA port from the monitor's PCB and hard wire directly in to make it flatter to fit into the lid.

I did consider attempting to route a cable internally to the SVGA output plug but my distant memory is that it's in a place where it just isn't practical to do it.

If I truely had skills like xxykevin, I could adapt everything to a stock screen - but I don't have that time, energy or knowledge.

I've got one more 230cs coming to me today. I don't mind working on them because I've found once you remember the correct ordering, it's easy to break down and put back with the only fiddly bit being the white wires going through the hinge area from the lid to the base. And nothing tends to snap or break.

It is in working condition so the DC board should be in good condition. I'll take some more photos as I recap.

cheers

[panips]

Any chance you shed more light on the IPS screen you used to replace the original one.
Also, is there any chance someone can share a picture from a fixed power subsystem board. I have a 230Cs that is dead and I am trying to fix it.

It looks like:




and, here are more details:
































Let me know if you need more details...

[update]
C5 33uf 10v
C10 22uf 16v
C14 18uf 50v
C2 15uf 25v
C1 150uf 25v
C31 47uf 6.3v
C11 33uf 10v

[solidpro]

That power board is a nightmare. I've got a bag of dud ones, i've tried to repair.