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141 comments
[DATA EXPUNGED]
Tube🍂Time replied to Tube🍂Time

it's working. that was a big step forward!

bitsavers.org replied to Tube🍂Time

@tubetime

I just checked and (thankfully) CHM doesn't have one. They actually have almost no ThinkPads in the collection. I have nightmares about how many early 90s machines in the collection have pcb rot.

Tube🍂Time replied to Tube🍂Time

it's really too bad the soft touch paint gets sticky. black? not quite -- it's got flecks of blue pearlescent pigment!

Tube🍂Time replied to Tube🍂Time

i would also like to comment that the 640x480 color LCD screen is utterly fantastic for 1992. it's active matrix and beats the crap out of the more common passive screens of the time

fraggLe! replied to Tube🍂Time

@tubetime Ugh I remember trying to play Jazz Jackrabbit on my first thinkpad, I couldn't see shit because of the passive matrix screen. Looked okay for productivity stuff, but anything fast moving was a blurry mess.

Andrew Certain replied to Tube🍂Time

@tubetime I had totally forgotten about active vs passive matrix displays!

LabSpokane replied to Tube🍂Time

@tubetime

The minute I saw an IBM active matrix LCD, I knew the end was nigh for the CRT. It was amazing for its time.

tecknicaltom replied to Tube🍂Time

@tubetime Active matrix, man. A million psychedelic colors... I bet it looks crispy in the dark.

Tube🍂Time replied to Tube🍂Time

cracking open the battery. it's ultrasonically welded shut. the trick is to find a weak point and start wedging it open.

Tube🍂Time replied to Tube🍂Time

then you just work your way around the seam, cracking it apart.

Tube🍂Time replied to Tube🍂Time

tada! looks like 18 cells total. maybe 2/3 AA sized?

Landy Manderson replied to Tube🍂Time

@tubetime The single strip of Scotch tape in the middle is a nice touch.

SLeiBt replied to Tube🍂Time

@tubetime Nice, can see 2 symetrical strings with temp sensor in the middle. Is the red wire connected to both strings in the far middle?

Tube🍂Time replied to SLeiBt

@SLeiBt yeah 2 parallel strings of 9 cells each

Tube🍂Time replied to Tube🍂Time

it died again. the problem was this via. I dug out the FR4 and reconnected it to the trace on layer 2.

Tube🍂Time replied to Tube🍂Time

back in business. for now anyway. 😅

Tube🍂Time replied to Tube🍂Time

I 3D printed a new power connector. the strain relief is printed using TPU.

Darryl Ramm replied to Tube🍂Time

@tubetime Did you have to make your own contacts of could you reuse something else?

Tube🍂Time replied to Tube🍂Time

any ideas about the type of connector the docking port uses? it's like a micro ribbon connector but with four rows instead of two rows. 240 pins total. pin pitch is 1.27mm. the only markings on the connector are "MXJ1" at one end and "52577A" at the other.

Tube🍂Time replied to Mark J Koch ✅

@maehem yeah i sorta think its a Hirose product but it's not DXM, which has only 2 rows of contacts, not 4.

DrYak replied to Tube🍂Time

@tubetime and apparently that specific one is only found on 700 and 720 series.
Source: thinkwiki.org/wiki/Docking_Por

Probably this one is ISA only, whereas the following series have PCI and/or CardBus.

Tube🍂Time replied to Tube🍂Time

i figured it out. it is the AMP .050 CHAMP line of docking connectors.

Tube🍂Time replied to Tube🍂Time

oh i should fix the backlight, which blinks on and off for some reason. time to take it apart!

Tube🍂Time replied to Tube🍂Time

welp, looks like i missed a few electrolytic capacitors. check out all that nasty corroded fuzz on the nearby component leads!

Tube🍂Time replied to Tube🍂Time

all cleaned up! i had to remove all those parts, add flux and reheat all the pads, scrub with IPA, and then put everything back in place. and replace the caps, of course.

Tube🍂Time replied to Tube🍂Time

it lights up and stays lit, so i'll call that a win. (yes, the hard drive still isn't working, so it's not booting.)

Tube🍂Time replied to Tube🍂Time

i just got the AC adapter for this! it came in from everyone's (not) favorite auction site. the listing conveniently forgot to mention that it REEKS of cigarette smoke. 🤢
oh well, at least it was cheap.

Tube🍂Time replied to Tube🍂Time

even the inside smells like smoke. it's not an ultrasonically-welded plastic case (just held together with 4 screws hidden under the labels) so it's definitely not airtight.

Tube🍂Time replied to Tube🍂Time

pulled the main power transformer for reverse engineering purposes.

Tube🍂Time replied to Tube🍂Time

last night i reverse engineered it. the design is simple so it wasn't too hard. the files are here: github.com/schlae/Thinkpad700C

Tube🍂Time replied to Tube🍂Time

it also explains the mystery "INPUT SIGNAL" pin on the old 4-pin IBM Thinkpad power connector. this pin simply increases the output current limit when it is pulled low by the laptop. it's because the power brick is also the battery charger, and when the laptop is turned on, you have to increase the current to compensate.

Tube🍂Time replied to Tube🍂Time

anyway, isopropyl alcohol wipes and a bath in Simple Green has mostly taken care of the bad smell.

Tube🍂Time replied to Tube🍂Time

now for that pesky docking connector: I've discovered that a 1.2mm PCB fits perfectly in the connector, so I made a set of two boards that stack and break out all the pins to 0.1" headers.

Jeff Haluska replied to Tube🍂Time

@tubetime Time to invent a rubbing alcohol pressure washer.

ĸurth replied to Tube🍂Time

@tubetime don't say 'just screws' … bless the screws

FozzTexx replied to Tube🍂Time

@tubetime I once got something that was so bad that the things inside that were still sealed in the original shrink wrap reeked of smoke when I took the shrink wrap off. I ended up throwing away most of the items.

Jeff Haluska replied to Tube🍂Time

@tubetime You're taking good care of the capacitors they're growing in size! 😆

Joe Pasqua replied to Tube🍂Time

@tubetime Now that would be a truly useful AI - upload a picture of a connector (perhaps with a ruler for scale), and it tells you what the connector is and where to get it.

Yours was a tough one, but its hard even for more common connectors. Next time I go to Anchor I’m going to take some stuff with me to see if I can find matching connectors.

Darryl Ramm replied to Tube🍂Time

@tubetime Others have speculated in the past that IBM used Nextel Suede coating. nextel-coating.com/produkt/nex. I am not sure if that info is correct. Difficult to get in the USA and $$$. I know folks who may have very limited quantities (used on aircraft instrument panels), may be the wrong color or variant.

Inmbolmie replied to Tube🍂Time

@tubetime

Regarding the hinge support replacements, I present you the 700c that came from death...

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