As promised, here's the beast itself.

Ok, does anyone know why the laptop has a slot covered by a removable metallic plate in the back? It looks like 8-bit ISA.

songoffall wrote on 2023-10-10, 10:33:

Ok, does anyone know why the laptop has a slot covered by a removable metallic plate in the back? It looks like 8-bit ISA.

I don't have an answer to the ISA question but I would like to encourage you to finish this restoration! I'm considering buying one of these antiques and wanted to see what problems you ran into.

Also interested in updates, one of this series just made a blip on the radar here, wondering if I want to deal with the double barrelled floppies, when mass storage with have to dangle from some orifice or another... dude on youtube has a zip drive on his, figuring I might use an SD to parallel or something hacked up with a parallel IDE board.

I would assume the blanked off connector was potentially for a docking bay or expansion chassis or something.

I am not sure if I should just be content with my Sharp PC-4640 but the screen is really horrible on that and it doesn't have a monitor port, while the zenith on the radar is supposed to.

songoffall wrote on 2023-10-08, 22:26:

I posted about the laptop that was plugged into the mains some time ago. […]
Show full quote

I posted about the laptop that was plugged into the mains some time ago.

I now have the said computer in my possession and am planning to resurrect it. Will post photos tomorrow.

It's IBM PC XT-class, quite large, with 80C88 CPU that can be clocked to either 4.77MHz or 8MHz. It's a 16-bit CPU, an upgrade over the 8-bit 8088. The RAM is 640k.

The power circuit will need extensive modifications - I don't have the original power brick and the batteries have been taken out - and I'll see what the capacitor and CMOS battery situation is when I open it up. The laptop is quite damaged and dirty and is literally falling apart.

It also has a 20Mb HDD.

The LCD screen is quite horrible if Youtube is to be believed, but that's to be expected. There's also an RGB/composite port on the back of the laptop.

If you have schematics and repair manuals for ZWL-180 series laptops, I'd be quite thankful. This is my first attempt restoring something this old.

Hello! Any news on restoring this laptop??

I have a similar model ZWL - 181 - 92, I don't have a charger to plug it in yet, but I opened it up to give it a clean.

I only opened the bottom part of the laptop and not the one with the monitor, but I was surprised by the good condition it is in. Only the power board that connects to the main motherboard was a little oxidized.

I would like to have some information about this small power board. Did anyone analyzed this power board?

If you made changes, what changes would you make?
I don't know if the components are working correctly and I wanted to make sure before connecting this. I can send photos!

Ps. Sorry for my English!

jrevez wrote on 2024-12-03, 19:59:

Hello! Any news on restoring this laptop?? […]
Show full quote

songoffall wrote on 2023-10-08, 22:26:

I posted about the laptop that was plugged into the mains some time ago. […]
Show full quote

I posted about the laptop that was plugged into the mains some time ago.

I now have the said computer in my possession and am planning to resurrect it. Will post photos tomorrow.

It's IBM PC XT-class, quite large, with 80C88 CPU that can be clocked to either 4.77MHz or 8MHz. It's a 16-bit CPU, an upgrade over the 8-bit 8088. The RAM is 640k.

The power circuit will need extensive modifications - I don't have the original power brick and the batteries have been taken out - and I'll see what the capacitor and CMOS battery situation is when I open it up. The laptop is quite damaged and dirty and is literally falling apart.

It also has a 20Mb HDD.

The LCD screen is quite horrible if Youtube is to be believed, but that's to be expected. There's also an RGB/composite port on the back of the laptop.

If you have schematics and repair manuals for ZWL-180 series laptops, I'd be quite thankful. This is my first attempt restoring something this old.

Hello! Any news on restoring this laptop??

I have a similar model ZWL - 181 - 92, I don't have a charger to plug it in yet, but I opened it up to give it a clean.

I only opened the bottom part of the laptop and not the one with the monitor, but I was surprised by the good condition it is in. Only the power board that connects to the main motherboard was a little oxidized.

I would like to have some information about this small power board. Did anyone analyzed this power board?

If you made changes, what changes would you make?
I don't know if the components are working correctly and I wanted to make sure before connecting this. I can send photos!

Ps. Sorry for my English!

I haven't got to restoring it yet; there's a lot of restoring to do, tbh, the case itself is falling apart so I might need to get a 3d printer just for that.

As for the power circuit, it is not very complicated, as soon as I'm done with my current projects I'll go over it and post the schematic here. If someone doesn't do it before I do.

I highly recommend that you check all the tantalum capacitors (mostly yellow) because their mode of failure is shorting and they can explode and take other parts with them. Safest bet is replacing them altogether with new ones.

songoffall wrote on 2024-12-04, 13:07:

I haven't got to restoring it yet; there's a lot of restoring to do, tbh, the case itself is falling apart so I might need to ge […]
Show full quote

jrevez wrote on 2024-12-03, 19:59:

Hello! Any news on restoring this laptop?? […]
Show full quote

songoffall wrote on 2023-10-08, 22:26:

I posted about the laptop that was plugged into the mains some time ago. […]
Show full quote

I posted about the laptop that was plugged into the mains some time ago.

I now have the said computer in my possession and am planning to resurrect it. Will post photos tomorrow.

It's IBM PC XT-class, quite large, with 80C88 CPU that can be clocked to either 4.77MHz or 8MHz. It's a 16-bit CPU, an upgrade over the 8-bit 8088. The RAM is 640k.

The power circuit will need extensive modifications - I don't have the original power brick and the batteries have been taken out - and I'll see what the capacitor and CMOS battery situation is when I open it up. The laptop is quite damaged and dirty and is literally falling apart.

It also has a 20Mb HDD.

The LCD screen is quite horrible if Youtube is to be believed, but that's to be expected. There's also an RGB/composite port on the back of the laptop.

If you have schematics and repair manuals for ZWL-180 series laptops, I'd be quite thankful. This is my first attempt restoring something this old.

Hello! Any news on restoring this laptop??

I have a similar model ZWL - 181 - 92, I don't have a charger to plug it in yet, but I opened it up to give it a clean.

I only opened the bottom part of the laptop and not the one with the monitor, but I was surprised by the good condition it is in. Only the power board that connects to the main motherboard was a little oxidized.

I would like to have some information about this small power board. Did anyone analyzed this power board?

If you made changes, what changes would you make?
I don't know if the components are working correctly and I wanted to make sure before connecting this. I can send photos!

Ps. Sorry for my English!

I haven't got to restoring it yet; there's a lot of restoring to do, tbh, the case itself is falling apart so I might need to get a 3d printer just for that.

As for the power circuit, it is not very complicated, as soon as I'm done with my current projects I'll go over it and post the schematic here. If someone doesn't do it before I do.

I highly recommend that you check all the tantalum capacitors (mostly yellow) because their mode of failure is shorting and they can explode and take other parts with them. Safest bet is replacing them altogether with new ones.

Thank you for your response!

I was wrong in the previous message, the model I have is the ZWL 183-92.
I opened it recently to clean it.

I bought it many years ago and have never turned it on since. I'm waiting for a 12V 2.5A charger to power it.

I read this on the forum - vcfed.org: "Today, I decided to make a small and entirely reversible modification to the little power board inside of the laptop. I discovered that removing the little choke coil from that board takes the DC barrel jack completely out of circuit, so I pulled that out, and then just ran wires from the jack straight to the positive and negative points for the battery, allowing me to plug my 12V 2.2A power supply into the side of the machine like normal! low power" light and the hard drive now works as it should! I also wired it for the more traditional center-positive, rather than center-negative like this laptop originally was."

I would like to know if this is really a good idea to do. My battery is probably dead and I've heard that without it, the laptop runs poorly.

Therefore, I will keep an eye on your publications here for new ideas for modifications to be made.

I finished the power board schematic today, I still have to review it with a friend who understands electronics and then I'll share it here.

I'll leave here photos of my board and the components it contains.

It might be useful to help someone

More...

and more...

Last one

jrevez wrote on 2024-12-04, 23:03:

Thank you for your response! […]
Show full quote

songoffall wrote on 2024-12-04, 13:07:

I haven't got to restoring it yet; there's a lot of restoring to do, tbh, the case itself is falling apart so I might need to ge […]
Show full quote

jrevez wrote on 2024-12-03, 19:59:

Hello! Any news on restoring this laptop?? […]
Show full quote

Hello! Any news on restoring this laptop??

I have a similar model ZWL - 181 - 92, I don't have a charger to plug it in yet, but I opened it up to give it a clean.

I only opened the bottom part of the laptop and not the one with the monitor, but I was surprised by the good condition it is in. Only the power board that connects to the main motherboard was a little oxidized.

I would like to have some information about this small power board. Did anyone analyzed this power board?

If you made changes, what changes would you make?
I don't know if the components are working correctly and I wanted to make sure before connecting this. I can send photos!

Ps. Sorry for my English!

I haven't got to restoring it yet; there's a lot of restoring to do, tbh, the case itself is falling apart so I might need to get a 3d printer just for that.

As for the power circuit, it is not very complicated, as soon as I'm done with my current projects I'll go over it and post the schematic here. If someone doesn't do it before I do.

I highly recommend that you check all the tantalum capacitors (mostly yellow) because their mode of failure is shorting and they can explode and take other parts with them. Safest bet is replacing them altogether with new ones.

Thank you for your response!

I was wrong in the previous message, the model I have is the ZWL 183-92.
I opened it recently to clean it.

I bought it many years ago and have never turned it on since. I'm waiting for a 12V 2.5A charger to power it.

I read this on the forum - vcfed.org: "Today, I decided to make a small and entirely reversible modification to the little power board inside of the laptop. I discovered that removing the little choke coil from that board takes the DC barrel jack completely out of circuit, so I pulled that out, and then just ran wires from the jack straight to the positive and negative points for the battery, allowing me to plug my 12V 2.2A power supply into the side of the machine like normal! low power" light and the hard drive now works as it should! I also wired it for the more traditional center-positive, rather than center-negative like this laptop originally was."

I would like to know if this is really a good idea to do. My battery is probably dead and I've heard that without it, the laptop runs poorly.

Therefore, I will keep an eye on your publications here for new ideas for modifications to be made.

I finished the power board schematic today, I still have to review it with a friend who understands electronics and then I'll share it here.

I'll leave here photos of my board and the components it contains.

It might be useful to help someone

Ah, I guess he's referring to connecting to the battery connectors directly - without the proper battery the laptop will have its low battery light on all the time. Essentially, unscrew the battery compartment and connect the PSU to the battery connector - note the polarity though - and you might have yourself a PSU posing as a working battery.

songoffall wrote on 2024-12-05, 23:35:

jrevez wrote on 2024-12-04, 23:03:

Thank you for your response! […]
Show full quote

songoffall wrote on 2024-12-04, 13:07:

I haven't got to restoring it yet; there's a lot of restoring to do, tbh, the case itself is falling apart so I might need to get a 3d printer just for that.

As for the power circuit, it is not very complicated, as soon as I'm done with my current projects I'll go over it and post the schematic here. If someone doesn't do it before I do.

I highly recommend that you check all the tantalum capacitors (mostly yellow) because their mode of failure is shorting and they can explode and take other parts with them. Safest bet is replacing them altogether with new ones.

Thank you for your response!

I was wrong in the previous message, the model I have is the ZWL 183-92.
I opened it recently to clean it.

I bought it many years ago and have never turned it on since. I'm waiting for a 12V 2.5A charger to power it.

I read this on the forum - vcfed.org: "Today, I decided to make a small and entirely reversible modification to the little power board inside of the laptop. I discovered that removing the little choke coil from that board takes the DC barrel jack completely out of circuit, so I pulled that out, and then just ran wires from the jack straight to the positive and negative points for the battery, allowing me to plug my 12V 2.2A power supply into the side of the machine like normal! low power" light and the hard drive now works as it should! I also wired it for the more traditional center-positive, rather than center-negative like this laptop originally was."

I would like to know if this is really a good idea to do. My battery is probably dead and I've heard that without it, the laptop runs poorly.

Therefore, I will keep an eye on your publications here for new ideas for modifications to be made.

I finished the power board schematic today, I still have to review it with a friend who understands electronics and then I'll share it here.

I'll leave here photos of my board and the components it contains.

It might be useful to help someone

Ah, I guess he's referring to connecting to the battery connectors directly - without the proper battery the laptop will have its low battery light on all the time. Essentially, unscrew the battery compartment and connect the PSU to the battery connector - note the polarity though - and you might have yourself a PSU posing as a working battery.

thank you very much 😀

Another question:

Unfortunately my knowledge of electronics is very limited and without a schematic of the board it becomes even more difficult.

I have been changing some electrolytic capacitors on the motherboard and on the bottom of the board there are other SMD ones.
I noticed that I have 3 smd capacitors that have continuity on both sides, and another one that neither side has continuity with the negative on the board, which makes me suspicious that something might be wrong.

Can anyone check on their boards?

Capacitors in continuity:

C79 - Upper right side
C80 - Lower right side
C81 - Lower left side
C82 - Upper left side

Capacitor without continuity with the negative on either side:

C54 - lower right side

Do you now know what value these capacitors can be?

jrevez wrote on 2024-12-12, 16:53:

thank you very much :) […]
Show full quote

songoffall wrote on 2024-12-05, 23:35:

jrevez wrote on 2024-12-04, 23:03:

Thank you for your response! […]
Show full quote

Thank you for your response!

I was wrong in the previous message, the model I have is the ZWL 183-92.
I opened it recently to clean it.

I bought it many years ago and have never turned it on since. I'm waiting for a 12V 2.5A charger to power it.

I read this on the forum - vcfed.org: "Today, I decided to make a small and entirely reversible modification to the little power board inside of the laptop. I discovered that removing the little choke coil from that board takes the DC barrel jack completely out of circuit, so I pulled that out, and then just ran wires from the jack straight to the positive and negative points for the battery, allowing me to plug my 12V 2.2A power supply into the side of the machine like normal! low power" light and the hard drive now works as it should! I also wired it for the more traditional center-positive, rather than center-negative like this laptop originally was."

I would like to know if this is really a good idea to do. My battery is probably dead and I've heard that without it, the laptop runs poorly.

Therefore, I will keep an eye on your publications here for new ideas for modifications to be made.

I finished the power board schematic today, I still have to review it with a friend who understands electronics and then I'll share it here.

I'll leave here photos of my board and the components it contains.

It might be useful to help someone

Ah, I guess he's referring to connecting to the battery connectors directly - without the proper battery the laptop will have its low battery light on all the time. Essentially, unscrew the battery compartment and connect the PSU to the battery connector - note the polarity though - and you might have yourself a PSU posing as a working battery.

thank you very much 😀

Another question:

Unfortunately my knowledge of electronics is very limited and without a schematic of the board it becomes even more difficult.

I have been changing some electrolytic capacitors on the motherboard and on the bottom of the board there are other SMD ones.
I noticed that I have 3 smd capacitors that have continuity on both sides, and another one that neither side has continuity with the negative on the board, which makes me suspicious that something might be wrong.

Can anyone check on their boards?

Capacitors in continuity:

C79 - Upper right side
C80 - Lower right side
C81 - Lower left side
C82 - Upper left side

Capacitor without continuity with the negative on either side:

C54 - lower right side

Do you now know what value these capacitors can be?

I'll open up mine when I get a chance and we'll compare notes, ok?

Well, I'd like to say that I finally got everything assembled and connected, and I was able to get it working from the floppy disk.

At least I had the opportunity to play Prince of Persia and make a backup of the original floppy disk that came with this Zenith. If anyone wants the .img, just let me know.

I made the jumper at the time, from the DC to the solder on the battery connector, both positive and negative, and it worked fine without the "low battery" light.

However, today I turned it back on, and after a while, the light started coming back on and making the famous beep.

I don't know if the third wire on the battery connector is related to the battery presence sensor or something, and it needs some voltage.

I also noticed that I don't have a backlight; I don't know how it works on these computers. I don't know if it's repairable or not. If anyone has any knowledge, it would be very helpful.

And another very negative thing is the screen housing is broken. Today I opened it again to remove the long piece of hardware that used to open and close it, as it's now quite stiff and won't rotate.

Ideally, I'd like to have a 3D-made housing
with some kind of functional system.

jrevez wrote on 2025-09-21, 17:05:

Well, I'd like to say that I finally got everything assembled and connected, and I was able to get it working from the floppy di […]
Show full quote

Well, I'd like to say that I finally got everything assembled and connected, and I was able to get it working from the floppy disk.

At least I had the opportunity to play Prince of Persia and make a backup of the original floppy disk that came with this Zenith. If anyone wants the .img, just let me know.

I made the jumper at the time, from the DC to the solder on the battery connector, both positive and negative, and it worked fine without the "low battery" light.

However, today I turned it back on, and after a while, the light started coming back on and making the famous beep.

I don't know if the third wire on the battery connector is related to the battery presence sensor or something, and it needs some voltage.

I also noticed that I don't have a backlight; I don't know how it works on these computers. I don't know if it's repairable or not. If anyone has any knowledge, it would be very helpful.

And another very negative thing is the screen housing is broken. Today I opened it again to remove the long piece of hardware that used to open and close it, as it's now quite stiff and won't rotate.

Ideally, I'd like to have a 3D-made housing
with some kind of functional system.

Sorry man, it completely skipped my mind that I had promised to help you with the power board.

As for the housing, the plastic on about all these laptops has deteriorated and is falling apart, so doing a 3d print seems like a must.

As for the backlight, I'm pretty sure you can just make one with some dimmable LED strips and a diffusion films.