Ad Widget

Collapse

Announcement

Collapse
No announcement yet.

Orange Bass Terror no filaments

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
  • #1

    Orange Bass Terror no filaments

    Customer said sound is dropping out, totally silent by the time I open it.
    All fuses good, High Voltage for preamp tubes is good (Class D power amp), but I have no 6.3V for the filaments, of course that means no pilot light or fan, also.
    I am completely ignorant to this power supply, so I'm wondering where I should start looking.

    Also for this heather supply, w no CT, am I correct in that I'll need to measure across , say C117 to get a reading(assuming I get it working)?

    Click image for larger version Name: orange_tb500_bass_terror_sch.pdf_2.png Views: 546 Size: 34.7 KB ID: 974899 Click image for larger version Name: orange_tb500_bass_terror_sch.pdf_2.png Views: 387 Size: 34.7 KB ID: 974900
    Tags: None
  • #2
    Which supplies have you got?
    +VCC and -VDD ?
    175v ?
    Support for Fender, Laney, Marshall, Mesa, VOX and many more. https://jonsnell.co.uk
    If you can't fix it, I probably can.

    Comment

    • #3
      Yes, I remember finding 180VDC on the 12ax7 plate supply, and also remember 50V when I was pokin around. That would leave me to believe the primary side is fine...

      Comment

      • #4
        Heater supply is called 'HT' in this amp. Since we don't see the full fan circuit, it's possible it doesn't run full time. So did you check F4 fuse?
        Originally posted by Enzo
        I have a sign in my shop that says, "Never think up reasons not to check something."


        ​

        Comment

        • #5
          Oops. I see you 'checked all fuses'.
          So do you have DC across C120 ?
          Originally posted by Enzo
          I have a sign in my shop that says, "Never think up reasons not to check something."


          ​

          Comment

          • #6
            Well crap, I've taken a step backwards now...
            So I fired up the amp just now to check about DCV across C120, and everything was working...filasments, fan, lamp... So this must be the intermittent part customer was originally talking about...
            So I'm tring to measure across C120 to check, and had my lead on where C120 meets L104, and I hit the same lead to the heatsink for IC1, and got a liuttle smoke and off course lost all filaments, again. For a different reason.
            So now I'm sure I fried some diodes in the bridge rectifier, and/or the inductor

            Comment

            • #7
              Maybe frying the diodes was the best thing that couldve happened to me today haha.
              While replacing them I noticed that a couple traces were damaged, with copper exposed, and one was barely making a connection. I wired it, and now the amp is working properly.
              Also, I'm getting 6V DC on the filaments, when before, when I was able to take a reading, I was getting 5.

              Thank you for the quick reples, it certainly got me headed in the right direction!!

              • Likes 1

              Comment

              Previous template Next
              Working...
              X