Search results

Search Forums New Posts
  1. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Installed new U2 R12/C6 connected to pin6 of u2 Adjusting P1 causes voltage on pin 6 to go from 0 to 7V
  2. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Audioguru Thanks P2 turned right down R7 voltage on one of the pins = 0.002V In - (Pin 2) = 0.94V In + (Pin 3) = 0.73V Any other Voltage I can check? P1 turned halfway
  3. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Fortunately my new 2N3055's arrived:
  4. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Thanks Audioguru Yes, my R1 is 2W. Well, on the pcb it's just next to R7 so I guess I'll just have to live with it. If I put U3 back I get my -1.5V on pin 4, It just disappears with U3 removed so I guess that's ok. U3 pad voltages with U3 removed: (U2 in situ) 1 0V 2 0V 3 0V 4 0.3V 5 0V 6 32V...
  5. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Just noticed that R1 the 2.2k resistor gets hot. Don't know if that's new, it's hidden under big R7, so probably have never felt it What next?:(
  6. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Apologies, not 0.3 but 0.03V
  7. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Thanks Audioguru, I wish I knew, will check
  8. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    I don't get this. 42V gets to D13, 32V leaves D13, then passes through 2 resistors totalling 22.2kΩ and arrives at pin 6 as 32V??? How is pin 6 going to end up not having some sort of voltage?
  9. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    With U3 removed pin at .3V or -.3V depending on probe orientation. Been hunting that voltage on pin 6 all day. Can only be coming from base of Q3 as far as I can see. If 10V zener D13's job is to drop voltage by 10V then it's still working. I am using resin core solder, don't know mix. Solder...
  10. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Pulled U3 and all voltages at 0 except pins 6 and 7 at 32.4V Busy checking to see why that is
  11. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    and U3 getting hot still Starting to despair
  12. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Just checked R21, connected to U3 pin 2 o/s and connection to C4 other side. I have 2 x spare TLl2141 but I am too scared to try them for fear of blowing them. Oh, and led still lit
  13. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    I was hoping that would sort U3. I think pin 6 on U3 s/b 24-28V but I am only seeing 1.7V
  14. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Well, I'm so relieved something is correct. Thank you
  15. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    On your Rev 6 the bars on the diodes are on R3 side ?
  16. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Swung them around . Seeing -1.5V across them
  17. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Thanks Audioguru. me hangs head with bleeding forehead in shame
  18. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Thanks for your endless patience Audioguru Can we please sort out the 2x D7 Here is a photo (please excuse state of board but it's been busy) Right hand leg of diodes connects to R3 Have I got them the wrong way round.? Not trusting myself anymore:(
  19. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Have reversed the BC557 but have not noticed any change Trying to hunt down the -1.3V. Have replaced C2 and C3. Resistance on R2 and R3 checks out (in circuit readings) Voltages across the following diodes: 2 x D7 = -3.9V D5 = -0.72V D6 = -0.72V Is this what they should be?
  20. bushtech

    Chinese Hiland 0-30V/Audioguru PSU build (down the rabbit hole)

    Have I got Q3 the wrong way round: Found a 9015 pinout here...
Top