User5518 wrote on 2024-11-22, 20:54:

Hello, currently, I have a Toshiba Satellite Pro 440CDT in front of me that unfortunately no longer boots and only shows this co […]
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Hello, currently, I have a Toshiba Satellite Pro 440CDT in front of me that unfortunately no longer boots and only shows this code:

https://imgur.com/a/iM9PPxa

Is this an error code? Does anyone happen to know what it means?

A bit of background information: I bought the notebook second-hand this week, and when it arrived yesterday, it was working perfectly fine. When I checked the BIOS battery, I noticed that it had leaked. Fortunately, in the 440CDT, the CMOS battery is located under the palm rest, so no circuit boards were damaged. I cleaned everything with vinegar and alcohol and let it dry overnight in a small room with a dehumidifier. After reassembling it, all I get is the blinking shown in the video. Naturally, I’d like to fix this. I’d really appreciate any help.

the "A" is the light for the caplocks, the fact its flashing must be an error code, if it worked when you first got it it could be that it wont boot without a cmos battery plugged in, i know people usually remove the battery for the restore function, and just replace the cmos for the RTC, both batteries on my 300CDT are dead but not leaking so i havent removed them so cant confirm if that is the cause of the flashing light, you best bet is to ask ThermalWrong he has threads on here as he collects and repairs a lot of Toshiba Satellites so he may have an idea of what the problem could be.

Thank you for your response. I will start by purchasing new BIOS batteries to replace the old ones. If that doesn’t solve the issue, I’ll ask ThermalWrong , if he might be able to help. I’ll definitely post an update here.

Unfortunately, it does not work with the CMOS / RTC battery (3,6V) alone. Here: same blink code. Hopefully, the second battery (7,2V, I guess for the "suspend to ram/disk"-feature) will arrive by the middle of the upcoming week. Then I can also test it with this one.

User5518 wrote on 2024-11-24, 07:58:

Unfortunately, it does not work with the CMOS / RTC battery (3,6V) alone. Here: same blink code. Hopefully, the second battery (7,2V, I guess for the "suspend to ram/disk"-feature) will arrive by the middle of the upcoming week. Then I can also test it with this one.

Yeah my dead 460CDT mainboard which has broken memory traces gives the same caps lock blink code, I checked it just now. It seems that's just some kind of startup indicator but isn't a meaningful error code. Your laptop doesn't start up the hard drive after it gives that blink code, right?

You should get hold of a parallel port POST code reader to see what code it's getting stuck on. Other than that you should remove the mainboard from the casing following this guide: https://archive.org/details/toshiba-service-m … 60cdtcdx-440cdt
Check the underside of the mainboard beneath where the RTC / standby batteries plug in, there's likely some corrosion. Clean it up initially with a Q-tip soaked in isopropyl alcohol to get the worst of it off, hopefully just a couple of traces need patching since this is a recent development. Although you've cleaned up the battery leak under the palm-rest, what happens is the battery's electrolyte wicks through the cables, usually the negative lead onto the mainboard and does damage from there.

I have 460CDT and 480CDT that work fine without the batteries. These 400 series are quite unreliable though. I have 4 dead ones. Two of which were working when I got them

@Thermalwrong: Thanks for the information. I've already ordered a parallel port POST code reader, but it will take a few weeks to arrive. Do you happen to know if the laptop outputs error codes via the data lines? I still have a small board from way back that connects the data lines with LEDs. I'm wondering if I could use it to read the codes (binary to hex).
Otherwise, I'll try opening up the device in the next few days to see if there's anything I can clean/repair.

@RetroPCCupboard
Thanks for the info, but I’m not ready to give up on the 440CDT just yet. 😉

I have now taken the 440CDT apart. Unfortunately (or luckily?), I couldn’t find any damage, except for one bug.

I really hope, that this was the problem:

Otherwise, the board still looks very clean:

Even in the corner where the BIOS battery was, no corrosion is visible:

I’m wondering if it’s a good idea to carefully clean the motherboard with isopropanol and a toothbrush.

Okay, it seems that not everything is as clean as it should be:

I’m wondering if the '220' / '330' SMD components are resistors and if I can test them with a multimeter.

The battery connections are also corroded:

I once heard that battery acid residue can be removed effectively with vinegar. Does anyone know if that would be a good option here?

User5518 wrote on 2024-11-27, 20:03:

I’m wondering if the '220' / '330' SMD components are resistors and if I can test them with a multimeter.

Yes, those are resistors of 22 Ohm and 33 Ohm respectively.

vstrakh wrote on 2024-11-27, 20:10:

Yes, those are resistors of 22 Ohm and 33 Ohm respectively.

Thanks, I just check very resistor. The 22 Ohm ones have a resistance of around 23,9 Ohm according to my multimeter (a "Metra Hit 26M"). I now assume that this is within the scope of tolerance.
The 33 Ohm ones have all a resistance of around 35 Ohm. Since they all have (more or less) the same resistance, I guess, that I don't have a problem here.
I also check some traces (the one, I was able to follow), and they were fine, too.

User5518 wrote on 2024-11-26, 20:55:

@Thermalwrong: Thanks for the information. I've already ordered a parallel port POST code reader, but it will take a few weeks t […]
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@Thermalwrong: Thanks for the information. I've already ordered a parallel port POST code reader, but it will take a few weeks to arrive. Do you happen to know if the laptop outputs error codes via the data lines? I still have a small board from way back that connects the data lines with LEDs. I'm wondering if I could use it to read the codes (binary to hex).
Otherwise, I'll try opening up the device in the next few days to see if there's anything I can clean/repair.

@RetroPCCupboard
Thanks for the info, but I’m not ready to give up on the 440CDT just yet. 😉

Haha, actually yeah it does. The Toshiba maintenance manuals show an 8-bit binary LED setup connected to the parallel port. That's how I was reading codes til I got the parallel port hexadecimal reader, so if you've got the LEDs then you can read the code that way. Your laptop should be stuck on hopefully code 05.

User5518 wrote on 2024-11-27, 20:03:

Okay, it seems that not everything is as clean as it should be: […]
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Okay, it seems that not everything is as clean as it should be:

The attachment IMG_2597.jpeg is no longer available

I’m wondering if the '220' / '330' SMD components are resistors and if I can test them with a multimeter.

The battery connections are also corroded:

The attachment IMG_2600.jpeg is no longer available

I once heard that battery acid residue can be removed effectively with vinegar. Does anyone know if that would be a good option here?

My recommendation at this stage is to use isopropyl alcohol to start with, most of that green stuff can be cracked off with pick tools. Putting vinegar on the board and leaving it for any length of time to fizz could finish off any weakened traces and make the repair more difficult.

This evening, I was able to reassemble the laptop after cleaning the affected areas with isopropanol (99%). Here are the after pictures:

I also connected my LPT board. (The board is now almost 20 years old, and I soldered it together in my younger years when I was learning in school how to use Java to interact with the parallel port. I never thought the board would ever come in handy again. What a coincidence...)

In the first step, right after powering on, all the LEDs light up (FFH), then they all turn off (00H). After that, "02H" lights up:

And then it gets stuck at "05H":

According to https://www.minuszerodegrees.net/manuals/Tosh … ce%20Manual.pdf, 05H means "SM-RAM check". So, I tested it with and without the RAM-module it came with. And: Same result. 🙁 But...

Fortunately, I still have an IBM ThinkPad 380Z, which, like the 440CDT, uses 144-pin EDO RAM. So, I installed the (IBM) RAM into the 440CDT:

Maybe I celebrated too early?!

Not sure if this is the Onboard-RAM or the RAM-Module, but I thought the Module are 64 MB... (Does the 440CDT has onboard-RAM?)

Edit: Okay, the Module I from the 380Z is a 32MB module. I just ordered one "Toshiba 64MB EDO 3,3V 60ns" module and one "IBM 64MB EDO 3,3V 60ns" for testing. Hopefully, the Toshiba module will work.

2nd edit:
This is the "original" RAM, the 440CDT came with:

I will test it tomorrow in my 380Z.

I went ahead and cleaned the module that came with the 440CDT, the RAM slot itself, as well as the area on the board around the slot with isopropanol.
And lo and behold:

It now works with the included module as well (without any error during POST).

Of course, it wasn’t a bad idea to remove the board from the laptop and clean it, but in the end, it seems the contacts on the RAM module just weren’t completely clean.

Once again, a big thank you to everyone who helped me here.

Well done for persevering! Maybe I should try this on some of my dead 460CDTs

User5518 wrote on 2024-11-29, 07:32:

I went ahead and cleaned the module that came with the 440CDT, the RAM slot itself, as well as the area on the board around the […]
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I went ahead and cleaned the module that came with the 440CDT, the RAM slot itself, as well as the area on the board around the slot with isopropanol.
And lo and behold:

The attachment IMG_2788.jpg is no longer available

It now works with the included module as well (without any error during POST).

Of course, it wasn’t a bad idea to remove the board from the laptop and clean it, but in the end, it seems the contacts on the RAM module just weren’t completely clean.

Once again, a big thank you to everyone who helped me here.

Ohh, I had assumed that your laptop had spontaneously stopped working because of corrosion, but expansion memory can cause problems too. I should have recommended removing any memory expansion modules *first*. Looks like the 440CDT only has 16MB of RAM vs the 460CDT's 32MB? So it's more likely that a 440CDT or 230CX will have a memory expansion board.
I've seen enough times where a perfectly working laptop has been taken down by bad contacts on a memory expansion and simply removing it makes it all work properly once more, usually because of dirty contacts. See my recent experience with similar problems on my 230CX, which was left in parts for long enough for some oxidation to set in on either the SO-DIMM slot or the module: Re: What retro activity did you get up to today?
Cleaning the original SO-DIMM's contacts with Isopropyl on a cotton bud is what would help and it appears it did 😀

Regarding installing an IBM module in place of the original, I'm not sure that will work? Looking at the pins vs my pinout document (taken from 500CDT maintenance manual and verified on my 460CDT), CAS0/1 pins are on pins 12 and 13 which looks like it's the case on your original module, but won't be the case on a JEDEC standard EDO SO-DIMM which puts VCC onto the CAS0 line.
The pinout of a Toshiba 144-pin EDO memory module is not JEDEC / IBM standards compliant either because it predates it or just Toshiba being Toshiba. It's possible that was causing some of your problems... There are pins on a Toshiba module / pinout that connect to 5v while the JEDEC pinout hooks them to Ground. Any SODIMM you install in a Toshiba laptop should be carefully inspected for a Toshiba part code or some note saying it's for a Toshiba laptop, standards were a mess back in the EDO days.
Edit a few days later: This is incorrect, Toshiba's EDO memory is JEDEC standard 144pin EDO SO-DIMM, however Toshiba in their maintenance manual use a different pin layout (1 to 72 in a strip, 73 to 144) from how SO-DIMMs actually lay it out, which is odd pins on one side (1 to 143) and even on the other (2 to 144). Both pinouts match up.

The traces on the mainboard look to be in pretty good shape overall since the gold test pads aren't too corroded and now you've cleaned off the worst of it it should be fine for a long time now.

Thermalwrong wrote on 2024-11-30, 03:24:

Ohh, I had assumed that your laptop had spontaneously stopped working because of corrosion, but expansion memory can cause problems too. I should have recommended removing any memory expansion modules *first*. Looks like the 440CDT only has 16MB of RAM vs the 460CDT's 32MB? So it's more likely that a 440CDT or 230CX will have a memory expansion board.

I had bought the laptop the week before last. After I received it, I turned it on immediately, and it booted up just fine. Then I unscrewed the palm rest and saw that the BIOS battery had leaked. After cleaning it with vinegar and isopropanol, it wouldn't turn on anymore. So your assumption wasn't entirely wrong. Unfortunately, I didn't perform a thorough test before cleaning, so I don't know whether the issue I currently (again) have already existed before the cleaning or not.

Thermalwrong wrote on 2024-11-30, 03:24:

Regarding installing an IBM module in place of the original, I'm not sure that will work? Looking at the pins vs my pinout document (taken from 500CDT maintenance manual and verified on my 460CDT), CAS0/1 pins are on pins 12 and 13 which looks like it's the case on your original module, but won't be the case on a JEDEC standard EDO SO-DIMM which puts VCC onto the CAS0 line.
The pinout of a Toshiba 144-pin EDO memory module is not JEDEC / IBM standards compliant either because it predates it or just Toshiba being Toshiba. It's possible that was causing some of your problems... There are pins on a Toshiba module / pinout that connect to 5v while the JEDEC pinout hooks them to Ground. Any SODIMM you install in a Toshiba laptop should be carefully inspected for a Toshiba part code or some note saying it's for a Toshiba laptop, standards were a mess back in the EDO days.

Okay, I wouldn't have thought that 'Toshiba EDO' RAM differs so much from 'IBM EDO' RAM or that Toshiba EDO RAM is so messed up. Thanks for the info!

I wanted to install Windows 95 on the 440CDT today and realized that my problems aren't fully resolved yet. I have two floppy drives for the 440CDT, but neither of them works. Fortunately, one of the CD-ROM drives I have for the device does work. So I booted from a Windows 98SE CD, partitioned and formatted the hard drive, copied the Windows 95 setup files, and started the setup from the hard drive. Scandisk completes successfully, you briefly see the Windows 95 setup, and then this appears:

I’ve encountered this error before on another system (Acer Desktop, 200MHz/233MHz). Back then, replacing the CPU resolved the issue: Re: Can't install Win98SE: "fault in MS-DOS extender"
I’ve also read that replacing the RAM has worked for others: https://www.techguy.org/posts/3151992/ (3rd post in this thread)

I first downloaded MemTest86, booted from the live CD, and tested the RAM:

(The test is still running in this screenshot, but even after three full iterations, no problems were found.)

What really confuses me is that during boot, 48MB is displayed:

However, MemTest only tests 32MB (see above for the MemTest execution). And here’s the kicker: without a RAM module, the laptop won’t boot and hangs at "05h," even though it supposedly has 16MB of onboard RAM. I’m wondering if the RAM chips on the mainboard are damaged.

Unfortunately, I only have this picture, but it doesn’t look great:

I’m wondering how I could have overlooked this.

In the next few days, I plan to disassemble the laptop again and clean those areas, hoping the chips haven’t suffered permanent damage.

Otherwise, I’m considering whether I could simply desolder the chips. I wouldn’t miss the 16MB onboard RAM, but I suspect the board might expect those chips to be present and refuse to function entirely if I remove them.

The board has "Toshiba TC51V16165CFTS-60" chips soldered on. Getting the exact replacements is tricky. I’ve found "Toshiba TC51V17405CST-60" chips and wonder if I could replace the "TC51V16165CFTS-60" with the "TC51V17405CST-60"? (I’ve already done RAM chip soldering before, so I have some experience. For example, I upgraded an AWE 64 Value from 512KB to 2MB successfully: https://www.reddit.com/r/vintagecomputing/com … bmod_on_a_abit/ – while writing this, I realized that the mod was introduced/created by you, Thermalwrong: Creative AWE64 CT4500 upgraded to 2MB of RAM. Thanks for that! It worked perfectly, though I was a bit nervous at times 😉 )

Is there any way to test the TC51V17405CST-60 chips? (Preferably without having to desolder them.)

(I also tested another 64MB RAM module from Toshiba, which was in the mail today. But with the 64MB-Module, I wasn't even able to start MemTest.)

Edit:
Okay, ChatGPT answered me the question, if I can replace the "TC51V16165CFTS-60" with the "TC51V17405CST-60":
TL;DR: No, I cannot / I shouldn't.

Based on the available information, the TC51V16165CFTS-60 and TC51V17405CST-60 are both EDO DRAM chips from Toshiba, but they ha […]
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Based on the available information, the TC51V16165CFTS-60 and TC51V17405CST-60 are both EDO DRAM chips from Toshiba, but they have different organizations and capacities:

TC51V16165CFTS-60: Organized as 1,048,576 words × 16 bits (1M × 16), providing a total of 16 Mbits.
DATASHEET ARCHIVE

TC51V17405CST-60: Organized as 4,194,304 words × 4 bits (4M × 4), providing a total of 16 Mbits.
OCTOPART

While both chips offer the same total memory capacity (16 Mbits), their internal organizations differ significantly. The TC51V16165CFTS-60 has a 16-bit data width, whereas the TC51V17405CST-60 has a 4-bit data width. This difference affects how data is accessed and managed within the system.

[...]

Recommendation:

Given these differences, it is not advisable to replace the TC51V16165CFTS-60 with the TC51V17405CST-60. To ensure proper functionality and compatibility, it's best to source a direct replacement that matches the original chip's specifications, particularly in terms of data width and organization.

[...]

But maybe I can replace the "TC51V16165CFTS-60" with one of these:

• Alliance Memory AS4LC1M16E5-60TC
• ISSI IS41LV16100A-60T
• Oki Semiconductor MSM5116165D-60

The Toshiba TC51V16165CFTS-60 is a 16 Mbit (1M x 16) EDO DRAM chip. Finding a widely available direct replacement can be challen […]
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The Toshiba TC51V16165CFTS-60 is a 16 Mbit (1M x 16) EDO DRAM chip. Finding a widely available direct replacement can be challenging due to the obsolescence of such components. However, here are some potential substitutes:

Alliance Memory AS4LC1M16E5-60TC: This is a 1M x 16-bit EDO DRAM with a 60ns access time, similar to the Toshiba chip. It operates at 5V and features extended data-out mode.
DIGCHIP

Integrated Silicon Solution Inc. (ISSI) IS41LV16100A-60T: This 1M x 16-bit EDO DRAM offers a 60ns access time and operates at 3.3V. Ensure your system supports 3.3V DRAM before considering this option.
DIGCHIP

Oki Semiconductor MSM5116165D-60: Another 1M x 16-bit EDO DRAM with a 60ns access time, operating at 3.3V. Verify voltage compatibility with your system.
DIGCHIP

Important Considerations:

Voltage Compatibility: The original Toshiba chip operates at 5V. Some alternatives operate at 3.3V. Using a 3.3V chip in a 5V system can cause malfunction or damage. Ensure your system can accommodate the voltage requirements of the replacement chip.

Package Type and Pin Configuration: Confirm that the physical package (e.g., TSOP) and pinout of the replacement match the original to ensure proper fit and function.

Availability: These components are considered obsolete, and availability may be limited. Check with electronic component distributors or specialized suppliers for stock.

Before proceeding with any replacement, consult your system's documentation or a professional technician to ensure compatibility and prevent potential damage.