Announcement

Collapse
No announcement yet.

Crate VC5310 power tube failure ,and fuse blown.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by MarkusBass View Post
    If the current is correct, this will be a waste of time. But if it is not correct, you could save some money (needed for new tubes). That's why I would do it. And it will help you to be on the safe side (I mean having the knowledge what is the current).
    Can you also make a photo of the cap in the middle (from a different angle)? It looks a little bit suspicious.

    Mark
    See attached. Most of them look bulged at the top ,but it's just the cover. I'll check the current tonight when I get home ,and report back tomorrow. Thanks Mark !
    Attached Files

    Comment


    • #17
      Originally posted by MarkusBass View Post
      On the schematic there is a jumper from cathode of the power tubes to the ground. You can disconnect it and replace with a meter set to DC current (range 200 mA). And report what current you get. This will tell you whether the bias is set correctly.

      Mark
      Should I do this with the limiter ?

      Comment


      • #18
        Bias current measurement must be done without the limiter.
        Originally posted by Enzo
        I have a sign in my shop that says, "Never think up reasons not to check something."


        Comment


        • #19
          Originally posted by g-one View Post
          Bias current measurement must be done without the limiter.
          Thanks g-one. I tried it with the limiter ,and got nothing at all. I'll try it again tonight without.

          Comment


          • #20
            Originally posted by gtrplayr1976 View Post
            Thanks g-one. I tried it with the limiter ,and got nothing at all. I'll try it again tonight without.
            Ok I tried without the limiter still no reading on JO3. Do I need all four tubes in ?

            Comment


            • #21
              You shouldn't need them all in.
              So you clipped the J03 wire and have your meter connected between the two sides of the clipped wire? Do you have your meter set for DC current range with the probes in the proper ports for current measurement?
              Is it auto-ranging or do you have a choice of range (200mA would be good) ?
              Does the meter have a fuse for current range that may be blown?
              Originally posted by Enzo
              I have a sign in my shop that says, "Never think up reasons not to check something."


              Comment


              • #22
                Originally posted by g-one View Post
                You shouldn't need them all in.
                So you clipped the J03 wire and have your meter connected between the two sides of the clipped wire? Do you have your meter set for DC current range with the probes in the proper ports for current measurement?
                Is it auto-ranging or do you have a choice of range (200mA would be good) ?
                Does the meter have a fuse for current range that may be blown?
                I have two power tubes in and all the preamp tubes. I clipped the jumper and put one lead on each part of the clipped jumper. The black lead is in the common port and the red in the Ma port. Set to 200ma. Meter set to dc voltage ?

                Comment


                • #23
                  Nope. You want your meter to read current, not voltage.
                  "I took a photo of my ohm meter... It didn't help." Enzo 8/20/22

                  Comment


                  • #24
                    Originally posted by The Dude View Post
                    Nope. You want your meter to read current, not voltage.
                    Ok so what did I not set correctly ?

                    Comment


                    • #25
                      You asked in your last post, "Meter set to dc voltage?"
                      The meter should be set to read current- not voltage.
                      "I took a photo of my ohm meter... It didn't help." Enzo 8/20/22

                      Comment


                      • #26
                        Your meter needs to be set to DCA or DC mA, not DC volts or millivolts. You said there is a 200mA jack for the probe so it must be able to measure current.
                        And be sure to take the probe out of that 200mA jack as soon as you are done. If you forget, your meter will be a dead short between the probes and fry something when you try to measure volts.
                        Originally posted by Enzo
                        I have a sign in my shop that says, "Never think up reasons not to check something."


                        Comment


                        • #27
                          Originally posted by g-one View Post
                          Your meter needs to be set to DCA or DC mA, not DC volts or millivolts. You said there is a 200mA jack for the probe so it must be able to measure current.
                          And be sure to take the probe out of that 200mA jack as soon as you are done. If you forget, your meter will be a dead short between the probes and fry something when you try to measure volts.
                          I`m pretty sure its set correctly. I`ll show you what I have.

                          Comment


                          • #28
                            Originally posted by The Dude View Post
                            You asked in your last post, "Meter set to dc voltage?"
                            The meter should be set to read current- not voltage.
                            I just wasn't thinking when I put that part in. What I meant was I had the selector set to DC.

                            Comment


                            • #29
                              Originally posted by g-one View Post
                              Your meter needs to be set to DCA or DC mA, not DC volts or millivolts. You said there is a 200mA jack for the probe so it must be able to measure current.
                              And be sure to take the probe out of that 200mA jack as soon as you are done. If you forget, your meter will be a dead short between the probes and fry something when you try to measure volts.
                              This is how I set the meter.
                              Attached Files

                              Comment


                              • #30
                                Originally posted by gtrplayr1976 View Post
                                This is how I set the meter.
                                It's correct. But you have to know that in such meters (only on current range) there is quite often a fuse and sometimes the fuse fails. In this case you can still measure voltages but you cannot measure any current. Please check that you can measure curent; connect the meter to a 9V battery with 1k resistor in series. If in this case you also get 0 mA, then you need to fix the meter (the fuse inside) first.

                                Mark

                                Comment

                                Working...
                                X