Guidance with Travelmate 4000m Restoration

[RetroPilot]

Hello, I picked up this treasure while thrifting an older tv. Told the manager I liked old tech and he pulled it from storage. The screen is excellent shape, it powers up to bios and the floppy drive spins loudly. I would like to install Windows 3.1 on it and run some classic games.
So far I ordered:

• CF card 512mb with reader
• IDE to CF adapter
• 16mb ram card on eBay
• Replacement cap for nib mouse / pointer stick

I disposed of the Ni-ca battery and scrapped the 300mn HDD. There is a corroded component near the HDD that concerned me (see pics). Would we be the next step in installing the OS? Additionally should I be concerned about the corrosion? Cheers!

 

[Istarian]

You might need to source a replacement battery to ensure the BIOS settings are retained, unless Windows 3.1 uses it's own disk drivers that don't rely upon DOS or the BIOS.

 

[RetroPilot]

I opened it up and it looks like the traces are damaged. How would you go about fixing?

 

[Istarian]

It really doesn't look that bad, just some damage to the solder mask.

I'd start by using a q-tip/cotton bud and some isopropyl alcohol to clean up any obvious residue. Then follow the traces and use a multimeter in continuity mode to see if there is actually meaningful damage to any traces.

NOTE: you need to test uninterrupted sections of trace, because resistors, capacitors, or active components aren't the same as a continous length of wire.

-----
EDIT

If there IS a problem then you have to run a fine wire (as short and flat as possible) between the points that should be connected.

I'm not positive on it, but I think any bends/corners in that wire should be as close to 90 degrees as possible without breaking the wire.

Supposing you're comfortable with fine soldering, you can use a fiberglass pen to scrape away the solder mask. Then use some fine wire (strip insulation at the ends so there is 1/8" to 1/4" of bare wire) to bridge over the damage area and solder it on either end. With this kind of work it may be better to just tin (put solder onto) a section of the wire itself and then set the wire near the trace segment and reflow that solder so it connects your new wire to the trace.

Watching a few videos might be useful here to get an overview of the process.

 

[AlexC]

A bit late to this but... I had one of these many years ago (486slc/25) and recently bought two more: 486 DX4/75 and DX4/100.

The battery in the 75MHz one had only just started to leak so I managed to salvage everything but the one in the 100MHz laptop had sent turquoise fur all over a nearby chip, damaging some legs. I don't have the eyesight or skill to replace those traces but I might have access to a service that can.

The damaged chip seems to be the primary IDE controller (there are two identical ones) and the laptop always reports "Fixed disk controller error" at startup. I assume that will go away if/when the chip is repaired. However, my board looks different to yours and the chips are a different size and name.

Meantime I use a boot floppy (having replaced the belt in the Citizen W1D) to load PCMCIA drivers and access a CF card in a PCMCIA adapter. I also have the docking station so I can run a SCSI drive in that.

These are great machines, well-built and with native DOS sound, but as with so many 90s laptops the plastic is becoming so brittle it falls apart if you glance at it too hard.

 

[Vitalic]

Hi guys. Can anyone make a picture of this area. Pins 9 and 10 are missing traces. I concern if pin 10 should go down….

 

[Istarian]

Is it really so hard to just figure out from the intact connections and a chip datasheet where the signals should be going?

https://www.ti.com/lit/ds/symlink/sn74abt245b.pdf

^ possibly some slight differences from the part in your board, but it looks like pin 10 should be connected to ground and pin 9 is A8 (of the A8/B8 pair).

 

[Vitalic]

the thing is ground goes from under the chip. And on my second picture it traces reminder seems to have both go 9 and 10 pin. The last one is right, but whether A8 is shorted on ground I’m not sure.

B signals goes to ide connection… but A goes in a hidfen layer of pcb.

Can anyone adwice how to trace this?

 

[Istarian]

the thing is ground goes from under the chip. And on my second picture it traces reminder seems to have both go 9 and 10 pin. The last one is right, but whether A8 is shorted on ground I’m not sure.

B signals goes to ide connection… but A goes in a hidfen layer of pcb.

Can anyone adwice how to trace this?

You could probably get away with a bodge wire connecting pin 10 on the right chip directly to pin 10 on it's neighbor to the left. No need to trace that out.

The situation with pin 9 is different, but if it's for the IDE connector then it must ultimately connect to the on-board IDE controller

 

[Istarian]

If you have this all taken apart, maybe you can take some pictures of the whole board?

The IDE controller may well be part of the chipset depending on the design. Or it could be implemented as a SCSI-IDE bridge, but that seems unlikely.

Just as a note, chances are good that a lot of stuff is attached to the ISA bus or the PCI bus (if present), so you might be able to trace where that goes to work your way toward potential condidates for the chip you want.

The 74x244 and 74x245 (where x stands for a group of letters identifying the logic family -- e.g. LS, S, F, HC, HCT, AHCT, and so on) are commonly used octal (8-bit) bus transceivers.

So any such chips you see are almost certainly sitting between a device and the bus it connects to.

 

[Vitalic]

I have a slightly different design rather than the topic starter's. On the opposite side, there is ic 35D 3D UK HCT244 which legs on one side are completely disconnected from the PCB. When the battery leaked, it went to the opposite side throw the holes. So my biggest fear is that the internal traces inside the PCB could be damaged as well.

Alright, it's time to practice microwiring. It looks so easy on YouTube, but it needs practice, practice.

 

[Vitalic]

Power supply has classic issues - caps to be replaced; 47Ohm resistor burned. I've seen a video on YouTube with exact the same problem.

 

[Istarian]

47 ohms isn't much resistance at all...

I think resistors usually burn up when you have a dead short, which could be caused by a failed capacitor.

You may want to see if you can work out if the 244s / 245s connect to that signetics IC and if so, how. Google isn't much use, but I suspect it's programmable logic of some sort.