Shame it doesn't have any onboard sound?
Take some nice pics of it running classic games. I would be looking for a replacement drive rather than trying to align it.
$55 + postage sounds reasonable if it's working 100%.

keenmaster486 wrote:

-Battery: 12V NIMH. I've taken it apart and I'm going to replace the cells with 8 AA rechargables since they fit in there with room to spare (is this safe? why wouldn't it be? 😉 )

Yes it is, i've done it in two laptops 😉 BUT, for safety reasons, don't throw away the thermal fuse and solder it in series with the new battery pack. You can wrap a wet cloth around it during soldering so it won't break 😜 Also there is probably a termal diode, it should remain in place too. Sometimes you can buy rechargable batteries wrapped in packets ready to use, so you don't have to solder individual cells.

When I buy some used components, I worry about what extent to which they were tested and whether they will actually work correctly. Lots of bulk liquidators toss around the phrase "fully tested" but it means nothing unless they actually explain what they tested and how. In the typical case, I worry that a seller has never used the thing in their lives and just acquired it somewhere, turned it on for 10 seconds, and then listed it for sale.
Best case is somebody who owned and used the item for years (thus able to speak from real experience that it works) and has also subjected it to recent and thorough testing to make sure it still works as it did before.

An example for me was a particular graphics card which I feared being DOA, so I bought the one which the seller had described owning since new and had photographed the final scene/results of a 3D benchmark, showing it was stable under stress.

Not sure what kind of tests would be appropriate and effective for a 486 laptop though.

A concern that I'd have with an old laptop is how it will be packed. When I buy fragile items, I like to buy them from sellers whose feedback indicates they have a lot of experience shipping those items. Lacking that, at least give some description of how you will pack the laptop so a buyer doesn't have to worry that you'll do anything dumb with it. 😀

bjt wrote:

Shame it doesn't have any onboard sound?

Yeah, the analogous model with onboard sound is the T4700CT, currently for sale on eBay for $100 plus $30 shipping 😵 You can still use a PCMCIA sound card though, if you can find one!

bjt wrote:

Take some nice pics of it running classic games. I would be looking for a replacement drive rather than trying to align it.
$55 + postage sounds reasonable if it's working 100%.

OK, cool. It should run DOOM reasonably well 😀 I checked eBay and there's a replacement for $5 and free shipping, so I'll probably get that.

adalbert wrote:

Yes it is, i've done it in two laptops BUT, for safety reasons, don't throw away the thermal fuse and solder it in series with the new battery pack. You can wrap a wet cloth around it during soldering so it won't break Also there is probably a termal diode, it should remain in place too. Sometimes you can buy rechargable batteries wrapped in packets ready to use, so you don't have to solder individual cells.

I kept the thermal fuse and diode - except I don't know which one is the fuse and which is the diode. I have one round part labeled with a voltage and amperage and "Microtemp". The other one is flat, has some mold on it, and labeled "70C". What is the difference, and if I was only going to use one of them, which would it be? I have two 4-AA battery holders I'm using, since they fit perfectly. And I can use a wire-crimper thingy instead of solder to connect them. It also has a temperature sensor, separate from the cells, passed through to the internal circuitry in the machine.

shamino wrote:

When I buy some used components, I worry about what extent to which they were tested and whether they will actually work correctly. Lots of bulk liquidators toss around the phrase "fully tested" but it means nothing unless they actually explain what they tested and how.

I see what you mean. Are there any good benchmarks I could use? I haven't done benchmarking before but there's always a time to start. I have used this machine for a lot of stuff over the four months I've owned it 😀 It works great for word processing and for games that sound good on the PC speaker (like Keen 😉 )

shamino wrote:

A concern that I'd have with an old laptop is how it will be packed.

I plan to pack it inside of the aforementioned case, with bubble wrap inside the case and around it, and in a nice cardboard box (not just an old crappy one left over from Christmas 🤣 )

keenmaster486 wrote:

I kept the thermal fuse and diode - except I don't know which one is the fuse and which is the diode. I have one round part labeled with a voltage and amperage and "Microtemp". The other one is flat, has some mold on it, and labeled "70C". What is the difference, and if I was only going to use one of them, which would it be? I have two 4-AA battery holders I'm using, since they fit perfectly. And I can use a wire-crimper thingy instead of solder to connect them. It also has a temperature sensor, separate from the cells, passed through to the internal circuitry in the machine.

By thermal diode I meant that temperature sensor 😉 and actually i probably wrongly called it a diode, it should be a thermistor 😜 it should be placed possibly close to one of the cells, you can even put some thermal paste there, because rise of temperature is a signal that the battery has charged. Your thermal fuse should look like this: http://shop.rabtron.co.za/catalog/images/thermal%20fuse1.JPG and the second thing you mentioned probably looks like this http://g01.a.alicdn.com/kf/HTB14wZsKpXXXXXEXp … jpg_640x640.jpg and it looks like it is a thermal fuse too, but honestly I didn't know that before i looked that up in google (mine didn't seem react to high temperature). I just left that barrel type fuse inside, taped to one of the cells and it's fine without that other thing.

Aha, aha. Yes, that's what my thermal fuse looks like (the round one) and that's the one I put in the pack.
But after loading 8 freshly charged batteries in the pack, the computer tries to start up and then gives me a low battery alarm and shuts down.
I checked the battery before starting the computer and it read 11.5V - not surprising since I've heard that rechargable AA batteries are usually a little less than exactly 1.5V. If I charge this pack using the computer's built-in charger, will it charge it to exactly 12V or a little above? And is it bad to overcharge these batteries like that? The most I can see them actually overcharging is about 1.6V (which comes to 12.8V). Any more than that and I'd be worried. What's your experience? Should I add another cell to get 12.9V at normal charge?

Oh well, the nominal voltage of a single ni-mh cell is 1.2V (it doesn't matter if it's a regular AA rechargable battery or an industrial-type cell). So, if that battery was rated 12V, you should have 10 cells, not 8 (and there were probably 10 cells originally, or five sets of 2 cells packed in cardboard tubes). The voltage will rise after charging, but thats normal. Fully charged battery should be ~14V, nominal voltage is for discharged battery (not exactly, but let's say). The laptop can tolerate voltage differences because it uses stabilizing circuitry. Overcharging is a bad idea, it just won't work, the excess voltage will turn into heat and degradate the battery very quickly. And, I don't think it would make it explode, but I wouldn't consider it to be safe.

So, add two cells and you will be fine 😉 but first discharge those 8 batteries a bit with a 12V lightbulb or something like this, so they will have roughly the same voltage as the cells you add... and/or charge new cells with a battery charger.

You're exactly right, it had five long cells in it - I'm assuming sets of two. So I'll add two cells. I actually just added one and it worked much better, but still only for about five minutes before activating the really cool "resume" feature 😀 So I'll have to add one more.