Hi, many thank for all guys comments
I have tried to checking and focus on around TF-245 and U139 first, then LM339 Ref...
On K2010, not sure the voltage quite difference from K2000 schematic or not ?
Using DMM to AGND TP-102 ..
U141 LM399...Ref voltage...
pin1 : 3.672 V
pin2 : GND
pin3 :+15.20 V
pin4 :-15.98 V
U139
Pin1: AGND
Pin2: -15.99 (-Vcc)
Pin3: -1.275
Pin4: -1.345
Pin5: -0.983
Pin6: 15.820 (+Vcc)
Pin7: -9.58
Pin8: -1.054
*It possible U139 have to defective, i feel quite hot by hand touch ?
On the attached image seem the +V to TF-247 below the range ?