Instead of a review IBM ThinkPad 755CD - restorer notes
Today I would like to tell you, dear readers, about another unusual and interesting piece of iron. But I will not tell ... instead, I will tell you how these old, rare and unusual pieces of iron help to break your head and, optionally, your hands.
So back to the year 2001. One frosty day, my friend Andrei, whose hobby and job is the sale of used iron on Juno (a large multi-assortment market in St. Petersburg), came to visit me and pulled out a small black brick fromwide trousers of an immense van - IBM ThinkPad 755CD. He, of course, knew about my love in black bricks (I collect them, work for them, and even go ... I don’t ride finkeets, of course) and decided to make me happy. He did it - the machine is in excellent external condition, a rare model and in an excellent configuration. Only one day darkened the day - when trying to boot, the car gave out “Levyke ei kelpaa” and reinstalling Finnish Windows to Russian did not have a fundamental impact on this inscription, only my language was a terrible curse word ... tests (say thanks to a good diagnostic system in the BIOS of ThinkPad's) showed an error operating memory, and digging inside allowed to clarify the bleak diagnosis - a failure in the soldered memory on the motherboard. So the laptop went to the shelf for several months.
The first attempt at revitalization was made a couple of months later, when I learned that, on this model, memory does not live on the motherboard, but on a small daughter's handkerchief. A little daughter's handkerchief located at the very bottom of the sandwich from the boards making up the laptop. Unfortunately, the laptop did not want to come to life without this handkerchief, or with a 4 megabyte motherboard (the native was at 8) from 755Cs. After that there was a move, a large expansion of the collection and much more - it was not up to him.
But now, on October 6 of this year, a potential donor was found on one of the ad sites, and in a better configuration. A few hours later, I already had a laptop. And now, let's digress from thisboring fascinating story and see what I'm talking about ...
')
So, we have a top model from 1994, the IBM ThinkPad 755CD, the first laptop with a built-in CD-ROM, and possibly the first laptop with an analog video input and a hardware video encoder card. Inside it has the fastest Intel 486 processor - already 100 MHz, 8 megabytes of RAM (looking ahead, I will say that it will be 16 megabytes for our hero), a hard disk of 810 megabytes (there were versions with a 540MB disk). A two-speed CD-ROM can be replaced with a floppy drive. Serious car.
Outside is a classic black-washed ThinkPad. At that time there were no ultrabooks and other thin devices, so that 56 mm of thickness was not something transcendent. The case is trimmed with soft-touch coating, the keyboard is raised for access to replaceable components - memory, battery, disk and drive. And now, having got acquainted with the laptop closer, we climbed into his gut!
Why do we do this? Let's start from the morning of October 7th. I took both laptops to the office, it was convenient to do the bulkhead there. Global things were not planned - just throw a cover with a matrix and a daughter board with slots for RAM in a new laptop - its cover was heavily scratched. And here began the difficulty. After assembly, the screen went to purple hues (one of the image channels disappeared). It turned out that the matrix connection connector was corrupted. It does not matter - we throw off the lid, remove the screen (and so, on both machines) and throw the top board out of the sandwich. It worked! We leave the laptop to work for a couple of hours ...
And here comes the fact that because of what today's review from the “review” of the laptop has become “the restorer's notes” ... the laptop is frozen. After re-enabling - only sees 4 megabytes of memory. After the removal of the plank, no changes occurred - again the trouble with the preinstalled memory ... we disassemble to the ground. I did not guess to photograph this process, despite the fact that I repeated it several times.
Frankly, it was very disappointing. But the desire to revive the laptop was stronger. I tried several combinations of boards, but without any result - one seems to be half the volume, the other gives an error when loading the OS. In one of the attempts - I forgot to connect the CMOS battery and the daughter's handkerchief with memory. In this embodiment, the machine booted without other errors and worked stably for more than an hour. Success.
We disassemble the boards collected on the knee and begin the assembly process “as it should.” That's just the internal structure and assembly process, and I want to devote the main part of today's story.
All modern laptops have one main, motherboard, board and it is often limited to it. In some cases, it is used daughter boards - for placement of connectors or optional controllers. Sometimes there is a video controller for a fee. But earlier, 15-20 years ago it was different: it was difficult to place everything on one board, there were many chips, the harness was more difficult. And if you still had to do something functionally rich ... As a result, the majority of laptops had a filling that was arranged in several layers. This is done in this device. The boards are placed in a separate compartment formed by a metal screen consisting of two parts - this also achieves the required structural strength - the case itself is made of plastic. The compartment with the boards occupies about a third of the internal volume of the case, the rest of the space is allocated for the replaced components.
Inside the screen is a sandwich from the boards. We consider them in the process of assembling a laptop. Dismantling, although it requires painstaking work, is trivial.
Let's start. We take in hand the main board - there is a chipset (Pico Power), a video controller (Western Digital with 1 MB of memory. There is no magnetic plates) and connectors for connecting other components. Below it is mounted on the connector that most ill-fated memory shawl ...
Insert the card into the bottom half of the screen. It is fastened to it with two screws simultaneously fixing the block of PCMCIA slots and the spacer screws of the external ports. From the bottom we join together the processor board (there is almost nothing beside it) - it completes the bottom of the screen with a heat sink plate. Also, the processor heatsink is used to preheat the hard drive during the cold winter months.
Now install the communication board. The IBM M-Wave controller - DSP, responsible for sound output and working with a telephone line, is soldered on it. It connects to the cover of the microphone cable and video processing board audio cable for speakers.
The next board is a VRM module.
The next step was to have a photo with the latest installed one from the big cards - the video processing card, which also brought LVDS from the video controller, the IR port and the connector for the external drive. On the board itself, there is a Philips 7110 chip and a microcircuit with hieroglyphic marking and number 7320, adjacent to a pair of RAM chips. The first, as I believe, is responsible for digitizing the analog signal, and the second acceleration of video encoding-decoding. Also through this board the signal is brought to the speakers. But the photo turned out to be unsuccessful and I had no opportunity to make it again. Therefore, in the photo - already closed shielded module installed in the housing.
The next step is to install the module into the case and connect the front IR port (for convenience, the ThinkPad has two IR ports installed for a long time), a memory power battery (used for warmly replacing batteries in standby mode) and a card with memory slots.
Now - install the keyboard - the bottom half of the laptop is ready.
A little distracted from the bottom - in front of you is a photo of the "fillings" of the cover - a matrix, a microphone and a loop. Of the two covers, I collected one - in one was a dead train, the other cover was very worn.
Finally, the finish line - we tighten the 4 screws that fasten the hinges of the cover, connect the display cable, inverter cable and microphone, set up the panel with LED indicators and throw on the case panel. The laptop is ready!
That turned out so handsome! The laptop is operational, we can assume that completely. There are only two problems - 8 megabytes less RAM than it would be if the clock settings were misaligned - if you connect a CMOS battery, an error 201 occurs, a memory error - the laptop is surprised that it does not have enough 8 megabytes ... why the error does not occur without a battery is not clear.
I hope the article didn’t turn out to be too messy and you won’t regret the time spent reading it) I apologize for the quality of the photo - the plans were a bit different and I didn’t take the camera with me.
The following review will be more classic) I will try. Thanks for attention! Stay tuned!
PS Comments accept comments on the topics of the following reviews.
PPS Tradionnaya link to the page of the exhibit (so far without a photo).
So back to the year 2001. One frosty day, my friend Andrei, whose hobby and job is the sale of used iron on Juno (a large multi-assortment market in St. Petersburg), came to visit me and pulled out a small black brick from
The first attempt at revitalization was made a couple of months later, when I learned that, on this model, memory does not live on the motherboard, but on a small daughter's handkerchief. A little daughter's handkerchief located at the very bottom of the sandwich from the boards making up the laptop. Unfortunately, the laptop did not want to come to life without this handkerchief, or with a 4 megabyte motherboard (the native was at 8) from 755Cs. After that there was a move, a large expansion of the collection and much more - it was not up to him.
But now, on October 6 of this year, a potential donor was found on one of the ad sites, and in a better configuration. A few hours later, I already had a laptop. And now, let's digress from this
')
So, we have a top model from 1994, the IBM ThinkPad 755CD, the first laptop with a built-in CD-ROM, and possibly the first laptop with an analog video input and a hardware video encoder card. Inside it has the fastest Intel 486 processor - already 100 MHz, 8 megabytes of RAM (looking ahead, I will say that it will be 16 megabytes for our hero), a hard disk of 810 megabytes (there were versions with a 540MB disk). A two-speed CD-ROM can be replaced with a floppy drive. Serious car.
Outside is a classic black-washed ThinkPad. At that time there were no ultrabooks and other thin devices, so that 56 mm of thickness was not something transcendent. The case is trimmed with soft-touch coating, the keyboard is raised for access to replaceable components - memory, battery, disk and drive. And now, having got acquainted with the laptop closer, we climbed into his gut!
Why do we do this? Let's start from the morning of October 7th. I took both laptops to the office, it was convenient to do the bulkhead there. Global things were not planned - just throw a cover with a matrix and a daughter board with slots for RAM in a new laptop - its cover was heavily scratched. And here began the difficulty. After assembly, the screen went to purple hues (one of the image channels disappeared). It turned out that the matrix connection connector was corrupted. It does not matter - we throw off the lid, remove the screen (and so, on both machines) and throw the top board out of the sandwich. It worked! We leave the laptop to work for a couple of hours ...
And here comes the fact that because of what today's review from the “review” of the laptop has become “the restorer's notes” ... the laptop is frozen. After re-enabling - only sees 4 megabytes of memory. After the removal of the plank, no changes occurred - again the trouble with the preinstalled memory ... we disassemble to the ground. I did not guess to photograph this process, despite the fact that I repeated it several times.
Frankly, it was very disappointing. But the desire to revive the laptop was stronger. I tried several combinations of boards, but without any result - one seems to be half the volume, the other gives an error when loading the OS. In one of the attempts - I forgot to connect the CMOS battery and the daughter's handkerchief with memory. In this embodiment, the machine booted without other errors and worked stably for more than an hour. Success.
We disassemble the boards collected on the knee and begin the assembly process “as it should.” That's just the internal structure and assembly process, and I want to devote the main part of today's story.
All modern laptops have one main, motherboard, board and it is often limited to it. In some cases, it is used daughter boards - for placement of connectors or optional controllers. Sometimes there is a video controller for a fee. But earlier, 15-20 years ago it was different: it was difficult to place everything on one board, there were many chips, the harness was more difficult. And if you still had to do something functionally rich ... As a result, the majority of laptops had a filling that was arranged in several layers. This is done in this device. The boards are placed in a separate compartment formed by a metal screen consisting of two parts - this also achieves the required structural strength - the case itself is made of plastic. The compartment with the boards occupies about a third of the internal volume of the case, the rest of the space is allocated for the replaced components.
Inside the screen is a sandwich from the boards. We consider them in the process of assembling a laptop. Dismantling, although it requires painstaking work, is trivial.
Let's start. We take in hand the main board - there is a chipset (Pico Power), a video controller (Western Digital with 1 MB of memory. There is no magnetic plates) and connectors for connecting other components. Below it is mounted on the connector that most ill-fated memory shawl ...
Insert the card into the bottom half of the screen. It is fastened to it with two screws simultaneously fixing the block of PCMCIA slots and the spacer screws of the external ports. From the bottom we join together the processor board (there is almost nothing beside it) - it completes the bottom of the screen with a heat sink plate. Also, the processor heatsink is used to preheat the hard drive during the cold winter months.
Now install the communication board. The IBM M-Wave controller - DSP, responsible for sound output and working with a telephone line, is soldered on it. It connects to the cover of the microphone cable and video processing board audio cable for speakers.
The next board is a VRM module.
The next step was to have a photo with the latest installed one from the big cards - the video processing card, which also brought LVDS from the video controller, the IR port and the connector for the external drive. On the board itself, there is a Philips 7110 chip and a microcircuit with hieroglyphic marking and number 7320, adjacent to a pair of RAM chips. The first, as I believe, is responsible for digitizing the analog signal, and the second acceleration of video encoding-decoding. Also through this board the signal is brought to the speakers. But the photo turned out to be unsuccessful and I had no opportunity to make it again. Therefore, in the photo - already closed shielded module installed in the housing.
The next step is to install the module into the case and connect the front IR port (for convenience, the ThinkPad has two IR ports installed for a long time), a memory power battery (used for warmly replacing batteries in standby mode) and a card with memory slots.
Now - install the keyboard - the bottom half of the laptop is ready.
A little distracted from the bottom - in front of you is a photo of the "fillings" of the cover - a matrix, a microphone and a loop. Of the two covers, I collected one - in one was a dead train, the other cover was very worn.
Finally, the finish line - we tighten the 4 screws that fasten the hinges of the cover, connect the display cable, inverter cable and microphone, set up the panel with LED indicators and throw on the case panel. The laptop is ready!
That turned out so handsome! The laptop is operational, we can assume that completely. There are only two problems - 8 megabytes less RAM than it would be if the clock settings were misaligned - if you connect a CMOS battery, an error 201 occurs, a memory error - the laptop is surprised that it does not have enough 8 megabytes ... why the error does not occur without a battery is not clear.
I hope the article didn’t turn out to be too messy and you won’t regret the time spent reading it) I apologize for the quality of the photo - the plans were a bit different and I didn’t take the camera with me.
The following review will be more classic) I will try. Thanks for attention! Stay tuned!
PS Comments accept comments on the topics of the following reviews.
PPS Tradionnaya link to the page of the exhibit (so far without a photo).
Source: https://habr.com/ru/post/196688/
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