NanTan Early 1990's laptops Guide (386/486/Pentium)

[RetroShare]

If you dont mind, can you please check whether CN3 and CN4 connectors in the notebook's internal power supply are connected to the screen and CN6 is connected to the videocard in your notebook?

 

[RetroShare]

Is there a cadmium battery inside the notebook?

Damn.

 

[Lou2000]

Hello, is there a replacement for the keyboard and battery? The right side of my keyboard doesn't work and the battery is dead. Are there drivers for the notebook? Thank you so much.

Hi, I've come home tonight, I way playing with my laptop and it froze and now won't boot, it just hangs here. I think I am going to give up because I seem to fix one thing and something else breaks. I'm tempted to strip and sell, do you want to buy my keyboard?

 

[Lou2000]

If you dont mind, can you please check whether CN3 and CN4 connectors in the notebook's internal power supply are connected to the screen and CN6 is connected to the videocard in your notebook?

All three are connected to the screen. When I took my laptop apart earlier today I didn't disconnect any of these three. I only disconnected like an earth on the video card and the video ribbon and I could then totally seperate the screen (still connected) and the power supply board from everything else.

 

[RetroShare]

At the weekend I noticed that when I switched on my 3500 (monochrome) the screen flickered like mad. I managed to adjust the brightness and contrast so the flicker was bearable and then after about 5 mins it was gone so didn't think anything about it. Monday, Tuesday all was fine. Yesterday the flicker was back, again for a few mins. Depending on how the brightness and contrast is set the flicker is literally as if the screen is off and on, not just a mild wave. As I say you can adjust the brightness and contrast so the flicker isn't so bad and then stops.

Anyone else had this? I'm worried it might get worse and worse. If it does I'll have to scrap it for spared.

That sounds like dead caps. There must be voltage drops. Time to replace them.

 

[Lou2000]

Damn.

You need to remove that asap before the junk starts eating your motherboard! I picked up a 3.6v Ni-Cd off eBay for about £3. And paid a local TV repair £10 to swop.

I went for a Ni-Cd, because being a Ni-Cd the motherboard must be able to recharge it. If you put a Ni-MH in, there's a good chance it will won't stop charging and then overheat as you need a cut off with Ni-MH and you don't with Ni-Cd.

 

[Lou2000]

Hi, I've come home tonight, I way playing with my laptop and it froze and now won't boot, it just hangs here. I think I am going to give up because I seem to fix one thing and something else breaks. I'm tempted to strip and sell, do you want to buy my keyboard?

Solved now, a piece of loose solder was left and had jumped onto the motherboard!!!

 

[RetroShare]

You need to remove that asap before the junk starts eating your motherboard! I picked up a 3.6v Ni-Cd off eBay for about £3. And paid a local TV repair £10 to swop.

I went for a Ni-Cd, because being a Ni-Cd the motherboard must be able to recharge it. If you put a Ni-MH in, there's a good chance it will won't stop charging and then overheat as you need a cut off with Ni-MH and you don't with Ni-Cd.

That’s a bad idea. You could replace it with a lithium cell and a shottky diode.

 

[Lou2000]

That’s a bad idea. You could replace it with a lithium cell and a shottky diode.

Too late, already fitted, today infact, picking it up 9.30am tomorrow. What's the shottky diode for? To mitigate against the charging current? If so do you put the diode on the positive or negative side? Positive, I'm guessing?

A lithium cell (Inc holder) would also be a good idea as the space between both boards is literally the width of the battery and there's no space to put a 3.6v Ni-cd a few mm's out of position once the upper board is attached.

I went for Ni-Cd as I wasn't sure the best way to prevent the motherboard trying to charge whatever was sat there.

 

[Lou2000]

That sounds like dead caps. There must be voltage drops. Time to replace them.

I bet its this one. It was about 1mm above the leaking battery.

 

[RetroShare]

I bet its this one. It was about 1mm above the leaking battery.

You can check all caps with a cheap measurement tool from Ali express or replace all of them with good new ones.

 

[Lou2000]

You can check all caps with a cheap measurement tool from Ali express or replace all of them with good new ones.

I "think" the cap is OK. I've washed all the gunk off with White Vinegar , and will observe to see if the flashing ever comes back.

When you say a cheap measurement tool from Ali Express? Do you mean a dedicated Capacitor Tester? I've a multimeter already.

I'm so pleased I've removed the leaking CMOS battery and now have a new one and my CMOS settings are all saved when I switch the laptop on.

 

[Lou2000]

The last job to do in restoration for me is the main battery. Its 2x5 Full Size NiCd C Cells. Full size C Cells are almost impossible to find singular. However you could use Sub C's or 4/5 Sub C's. I've found somewhere in the UK that supplies a 5 cell stick for £17. I'm looking to buy 2, however the company is asking the supplier if they will make me a 10 cell stick.

I've included pictures incase they are helpful to others.

 

[creepingnet]

The last job to do in restoration for me is the main battery. Its 2x5 Full Size NiCd C Cells. Full size C Cells are almost impossible to find singular. However you could use Sub C's or 4/5 Sub C's. I've found somewhere in the UK that supplies a 5 cell stick for £17. I'm looking to buy 2, however the company is asking the supplier if they will make me a 10 cell stick.

I've included pictures incase they are helpful to others.

I've been doing more digging on the batteries for these. I think I found some useful information cross referencing your battery number#

It seems most of the batteries intended for these laptop's (FMA3300, FMA3500/C/SX, FMA3540) battery casings is also sold as a LAP-220 battery pack. - https://www.batterytex.com/browse/manufacturer/klh - made by KLH apparently.

Anyway, I took some Gut Shots of my own NanTan FMA3500C/BSi 486DX/33 Notebook this afternoon. I finally replaced the CMOS battery with one from a Dell Latitude E-series. It seems to work great. Right now it's idling on my desk.FMA

 

[Lou2000]

The main battery in that link looks good.

I do like the way you have replaced the battery. However, isn't there an increased risk of leakage because when the laptop is on, the motherboard is expecting to be charging a Ni-Cd?

 

[creepingnet]

The main battery in that link looks good.

I do like the way you have replaced the battery. However, isn't there an increased risk of leakage because when the laptop is on, the motherboard is expecting to be charging a Ni-Cd?

The pictures don't do justice. One whole side of the Varta Battery was covered in white/tan corrosion, and a group of surface mount diodes/caps/resistors seem to have been hit as well. The battery only read 0.16vdc so it probably started leaking out once already dead. I sold my GEM 286 desktop that also had a (just barely) leaky Varta and it was still working after 33 years of faithful service somehow (!?!?). I don't think these computers always recharged the CMOS battery even if they had one capable of it. I know my 9200 sure does - and it uses a Lithium Ion coin cell. Since I've been running that on the regular it's not lost it's settings, but when I first got it, I could not remember it's CMOS settings to save it's life. I cleaned the area with Mass Airflow Sensor cleaner

I'm going to give this a go and see if it works. So far so good, I've had it off for quite a bit, then powered it back on again, and it started right up without me putting in the CHS, so for now at least, it's working. I still need to dig around my storage space and find where I put the battery for it though. I'm playing with an idea of putting a rechargable Li-Ion Batery with a BMC between the original BMC and the battery. That way the BMC just sees an old NiCAD per the math, but the secondary is seeing the actual, higher capacity, more efficient, LiIon.

Right now I'm letting the screen run for awhile. Something else I noticed about my 9200's DSTN screen is it has gotten better the more I've used it. Last night I was playing Hoyle Card games on it and it looked almost as good as my Active Matrix NEC Versa laptops, save for the ghosting thing. I'm also noticing this one gets a little more "crisp" if I let it warm up awhile. Sometimes even baking them with the lid closed and the screen on seems to help somewhat, going from overly bright and a bit faded to a crisper, deeper color.

I'm always experimenting with these things, but my experiments tend to come from the same place Eddie Van-Halen's guitar experiments come from (I'm also a guitarist)...except I tend to figure out later why scientifically this is and why it works, or find someone else found a better way, sometimes using my input.

 

[creepingnet]

Figured out another trick on the FMA3500 series today while poking around - I figured out how to get the Turbo to work on it (ie turn it off to slow it down for older games)...

(Excript from my website)
Turning Turbo On and Off - The FMA3500 series comes with an ability to slow down like a lot of desktops at the time did. How this is done, is by using the control combination CTRL+ALT+↑ to turn Turbo On, and CTRL+ALT+ ↓ to turn turbo off.

Slowing it down makes it more like a fast 286 or a 386SX from my experience. Kinda' cool. Have to wonder if the FMAK9200 is similar in this fashion, though it uses a different BIOS (AWARD vs. the Phoenixview Technologies BIOS used on the FMA3500 series).

 

[Lou2000]

I am already to rebuild my external battery. 4 screws to undo. Saved the cable from the original Ni-Cd to then solder onto a new pack. I did have the option of buying a 10 C Cell wrapped just like the original, but I have gone for 2x 5 C Cells because then I can replace half the pack if needed later on.

I paid £40 Inc delivery (UK).

These batteries are fairly easy to source if you search for "Emergency Lighting Batteries". See screenshot.

The original pack came with C Cells. Obviously Sub C and 4/5 Sub C will be suitable also. But don't buy D Cells, they will be too big.

Can't wait to finish the restore!

To recap, work done so far:
1) Replaced leaking Ni-Cd CMOS battery.
2) Cleaned away leaked Ni-CD from both the board it was attached to, but also the board
above. I had leakage over the legs of a capacitor which was causing screen flicker intermittently. I used white vinegar to clean.

 

[creepingnet]

Figured out another trick on the FMA3500 series today while poking around - I figured out how to get the Turbo to work on it (ie turn it off to slow it down for older games)...

(Excript from my website)
Turning Turbo On and Off - The FMA3500 series comes with an ability to slow down like a lot of desktops at the time did. How this is done, is by using the control combination CTRL+ALT+↑ to turn Turbo On, and CTRL+ALT+ ↓ to turn turbo off.

Slowing it down makes it more like a fast 286 or a 386SX from my experience. Kinda' cool. Have to wonder if the FMAK9200 is similar in this fashion, though it uses a different BIOS (AWARD vs. the Phoenixview Technologies BIOS used on the FMA3500 series).

Yep, tried it on the NanTan FMAK9200C this morning - it works! There's even a Turbo LED.

 

[Lou2000]

My NanTan was working great and I was switching on every day. Been about 5 days since I last used it, booted into DOS fine. I left it 5 mins and came back to this. Switched it off and on and now nothing on the screen. I've had this happen before but had been fine. I'm not sure if using everyday was in some way maintaining a good stability. I'm quite annoyed as I've spent a bit on new C Cells for the main battery and a new CMOS battery. Someone has suggested getting all the capacitors changed but I don't really want to spend any more without feeling confident.

Any ideas?