Gregory's Serverlooks like an SCR crowbar circuit is firing. I think I'm going to have to reverse engineer this board so I know what's going on.
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206 comments
 @johnlogic good eye, it took me half an hour of inspection to notice that and prove that it was the SCR firing... i really love it when a board has designators all out of order. bad? no! it means it's in order on the (implied) schematic, modulo revisions. very useful information! looks like the only electrolytic capacitor on the board had leaked, and the electrolyte etched and broke 6 vias. let's see if my repair worked...    Therapist: So you have nightmares about electrolytic capacitors? Patient: Yes. Therapist: And they are following you around? Patient: Yes. Therapist: And you think they want to harm you? Patient: I know they do.   @tubetime I loved that thinkpad. such a solid machine! And the nipple mouse was super.  @tubetime Problems solved by whacking with hammer: *adds one to the tally*  @tubetime I'm not sure, but I think your sheet size is a tad bit too small for your schematic
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@tubetime Huh? On a power supply board? What sub-circuit are these resistors part of?  @tubetime the one and only time I soldered directly to a coin cell it exploded in my face. Never again! @tubetime You need a small spot welder in your arsenal (and so do I) @tubetime I’m too scared to do that, so I use electrical tape to tape the wires to the cell (plus cover the whole thing with said tape so it looks similar to the original)  @tubetime You can just use a regular soldering iron for this and for the small parts you'll need a finer mesh, can find it on amazon https://www.amazon.com/dp/B0B3T3ZBSR . Holds much better than the glue  |
@tubetime
Nice to see SCR1 in the legend left of the orange sticker...