Chosen Solution
After running a aht it gives an error : 4SNS/1/40000001: VP0R-0.000 what is the exact problem in this logic board. System is very slow . i already dismantle 3-4 times some time after assembly it works for little time means working until restart. after restart it again giving same problem.
Run the extended version of the Apple Hardware Test. Sometimes you will get an error if you run the quick version, and it may be something of a false positive. Some have found doing an SMC reset 3 or 4X can eliminate the error (note: a work around not a fix). If it is indeed a logic board error it points to a sensor(s) failing, VPOR might be VGC(VPU) related. You’ll probably need a new logic board, AFAIK sensors as well as the VGC are soldered to the logic board which pretty much makes them non-DIY repairs, as soldering on logic boards are not for amateurs. If this answer was helpful please remember to return an mark it Accepted.