I think it has been, but I need to verify with the previous owner. He fixed a couple of corroded traces before giving it to me, and many of the caps look newer, so it's possible he replaced some of them. This laptop has been through a lot. For the full picture, here's what I fixed on it:
* Repaired 3 ripped/cut traces on the main board (previous owner damaged them by pulling out chips to try and isolate a short) * Repaired a short on VB (the aforementioned short that the previous owner was looking for). Solder mask on one of the VB traces had flaked off and there was a nearby solder joint (which looked like a factory joint) touching it. * Repaired broken via from T23 to the LCD connector (the LCD issue I mentioned earlier) * Cleaned and retightened LCD zebra strips (various pixel columns were out) * Found and repaired shorts on two separate LCD driver chips (there was ghosting between adjacent columns in two parts of the LCD) * Repaired broken keyboard trace on PA7 (none of the function keys worked) * Repaired broken keyboard trace, which prevented the caps and num lock keys from working. So yeah... I might as well do a full recap just to round this one off and see if it brings down that current draw. It wouldn't surprise me if there's another short somewhere else on the board, and I just haven't discovered it yet - I haven't used the modem or serial port yet, so who knows. As far as repairs are concerned, this one has certainly been one of the more problematic M100s I've worked on! Super satisfying when I finally got it booted, though - lots of fist pumping! //Ken S ________________________________ From: M100 <m100-boun...@lists.bitchin100.com> on behalf of Josh Malone <josh.mal...@gmail.com> Sent: Monday, February 5, 2024 8:44 AM To: m...@bitchin100.com <m...@bitchin100.com> Subject: Re: [M100] LCD Troubleshooting Advice On Mon, Feb 5, 2024 at 8:35 AM Ken St. Cyr <k...@stcyrfamily.net<mailto:k...@stcyrfamily.net>> wrote: Finally got it - boy, this one was a pain to hunt down. Turned out to be a failed via between the contrast pot and the LCD connector. A quick bodge did the trick (photo attached for anyone curious). The current draw is still a bit high (around 80mA) but everything seems to work 🤷 Nice! Has the unit been recapped? High current draw (in my experience) is an initial sign of failure due to the M100's notoriously leaky capacitors. All M100s need a *complete* recap, regardless of apparent condition. -Josh
