i’ve been using a gift tp25 for some years. it’s a special lenovo laptop edition that is similar to the t470 and t480. as the years have passed, it gets harder to find information on repairing this laptop online.<div dir="auto"><br></div><div dir="auto">last time or two ago i replaced the system board, i engaged a long list of substitute part numbers for system boards that would fit and boot. i haven’t found this list again. i originally made it by looking at simple commonalities on <a href="http://support.lenovo.com">support.lenovo.com</a> and <a href="http://ebay.com">ebay.com</a> , but simple search terms do not return as many results now as they did before, and <a href="http://support.lenovo.com">support.lenovo.com</a> is only showing one system board now for my model number.</div><div dir="auto"><br></div><div dir="auto">i’m seeing these values in the bios atm:</div><div dir="auto">bios ver: N1QETA3W</div><div dir="auto">ec ver: N1QHT54W</div><div dir="auto">model: 20K70004US</div><div dir="auto">unit serial: PF12XKZP</div><div dir="auto">board serial: L1HF83M000D</div><div dir="auto">cpu: i7-7500u 2.7ghz</div><div dir="auto">uuid: 1f4bfcc-2c71-11b2-a85c-955ac813bb93</div><div dir="auto">os license: SDK0J40697</div><div dir="auto">oa3 id: 3305102936368</div><div dir="auto">may have made copy mistakes</div><div dir="auto"><br></div><div dir="auto">the problem i have right now is that the system does not charge, instead emitting a pungent smell for some time after the charger is plugged in.</div><div dir="auto"><br></div><div dir="auto">i removed the bottom cover but</div>