PS 305D : Voltage is not going to its Max

[Jaival]

Hi

   Having PS 305D and Previously Voltage is controlled by "Fine" and "Coarse" Knob of Supply and able to vary output from 0 to 30V .
   But now  there is hardly any effect of "Fine" Knob . And with "Main/Coarse" Knob able to vary Volt till 12 V and not reaching to it max value .
   But With Current "Fine" and "Main/Coarse" Knob able to reach to 5A .

   Checked the following :
      1)   Transformer output seems fine
             Transformer output AC1 to AC2  ~ 7v
             Transformer output AC1 to AC3  ~ 22v
             Transformer output AC1 to AC4  ~ 38v     
 
     2)  Both Relay is working (Manually checked)
     3)  "Coarse/Main" And "Fine" Knob of Volt seems fine as when rotating Voltage is varying @ out (Middle point) of POT.
     4)  Reference  O/P at LM324 is -10.76 V and @ TL431A is 3.2V 
 
   And having the same schematic and PCB which is present in below Thread .
   https://www.eevblog.com/forum/repair/new-power-supply-ps305d-not-regulating-and-running-over-voltage-and-current/

   So please can i have any suggestion what can be issue ?

 

 Regards
+Jaival

[syedhussain_alishah]

did you find the problem.?