Need help testing an oscillator.

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • reaper57
    Badcaps Veteran
    • Sep 2014
    • 216
    • Norway
    #1

    Need help testing an oscillator.

    Hi,
    I have never tested an oscillator, but I think that I have one that might be faulty. It's a 20mhz one it says H20.000M2 on top of it if it matters.
    I have heard from somewhere that it is possible to test it somehow (with some resistors and a cap, I think) without an oscilloscope. I don't have a scope so this is the only way for me to test it.
    Also is there a way to bypass it somehow? By that I mean make something that acts as an oscillator or something like that.
    If anyone cares it's from a j-r programmer v2. A nand and jtag programmer.
    Any advice is welcome!
    P.S. What would happen if I put a 48.000M one in there?
    Last edited by reaper57; 01-16-2015, 03:10 PM.
    Keyboard not detected, press F1 to continue...
    Tags: None
    • eccerr0r
      Solder Sloth
      • Nov 2012
      • 8682
      • USA
      #2
      Re: Need help testing an oscillator.

      If you make a high pass filter with a resistor and cap and then a low pass, then perhaps you can get some indication of functionality; but a scope and frequency counter is still the best way.

      This is a very crappy HPF-LPF:

      C1 IN n1 0.001uF
      R1 n1 GND 10K
      R2 n1 OUT 1K
      C2 OUT GND 0.1uF

      If you get some voltage at the OUT port when the oscillator can is on, then likely it's at least somewhat working; if it's 0V then it's dead.

      This is for oscillators, if it's a simple passive crystal, you have to amplify it.

      You probably can't really bypass it except with another oscillator of the same frequency, alterations could cause problems with the microcontroller.

      Usually oscillators don't go bad, at least I haven't had one die yet.

        Comment

        • budm
          Badcaps Legend
          • Feb 2010
          • 40746
          • USA
          #3
          Re: Need help testing an oscillator.

          Are you trying to test the crystal by itself or the oscillator module/board?
          Do you have short wave radio that you can put close to the board and then you may be able hear changes on the radio?
          Last edited by budm; 01-16-2015, 03:37 PM.
          Never stop learning
          Basic LCD TV and Monitor troubleshooting guides.
          http://www.badcaps.net/forum/showthr...956#post305956

          Voltage Regulator (LDO) testing:
          http://www.badcaps.net/forum/showthr...999#post300999

          Inverter testing using old CFL:
          http://www.badcaps.net/forum/showthr...er+testing+cfl

          Tear down pictures : Hit the ">" Show Albums and stories" on the left side
          http://s807.photobucket.com/user/budm/library/

          TV Factory reset codes listing:
          http://www.badcaps.net/forum/showthread.php?t=24809

            Comment

            • SM-Piyes90
              Senior Member
              • Feb 2014
              • 120
              • Morocco
              #4
              Re: Need help testing an oscillator.

              I think he is talking about a console stuff , the j-r programmer is supposed to program a RGH chip used on xbox 360 consoles .

                Comment

                • SteveNielsen
                  Retired Tech
                  • Jun 2012
                  • 2327
                  • USA
                  #5
                  Re: Need help testing an oscillator.

                  A simple crystal tester ckt:
                  http://electronics-lab.com/projects/test/010/

                    Comment

                    • mmartell
                      Badcaps Legend
                      • Oct 2013
                      • 3189
                      • Canada
                      #6
                      Re: Need help testing an oscillator.

                      If you think it is faulty it is probably simplest to replace it but you do raise a good question because I've read scoping it can shut it down anyway.

                        Comment

                        • eccerr0r
                          Solder Sloth
                          • Nov 2012
                          • 8682
                          • USA
                          #7
                          Re: Need help testing an oscillator.

                          It looks like it uses a crystal and not an oscillator, the amplifier is in the chip on that board. So a simple hpf-lpf test wont work, you'll need to isolate it as the load produced by the test will cause the oscillator to stop working...

                          They're cheap enough, agreed, just replace.

                            Comment

                            • Agent24
                              I see dead caps
                              • Oct 2007
                              • 4939
                              • New Zealand
                              #8
                              Re: Need help testing an oscillator.

                              Unless it was dropped, the crystal is probably OK, and likely you have some other problem. I have yet to find a bad crystal aside from one in a laptop that was physically smashed.
                              "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
                              -David VanHorn

                                Comment

                                • redwire
                                  Badcaps Legend
                                  • Dec 2010
                                  • 3900
                                  • Canada
                                  #9
                                  Re: Need help testing an oscillator.

                                  Without having a scope, just make an RF probe (cap and a diode) and your multimeter set to DCV. You are just looking for the presence of AC.

                                    Comment

                                    • reaper57
                                      Badcaps Veteran
                                      • Sep 2014
                                      • 216
                                      • Norway
                                      #10
                                      Re: Need help testing an oscillator.

                                      Thank you to everyone that has replied to this thread! @SM-Piyes90 that is correct! It's not only used to program the RGH chip, but it is also has an SPI that is used for r/w the nand.
                                      @eccerr0r Isn't is called a crystal oscillator? The crystal or the oscillator or the crystal oscillator or however it's called wasn't soldered all the way in the hole on one side, and it did spend a few hours in my laptop's bag. But I am careful with it so I don't know if it got too much vibration from there. I ordered the replacement on Friday, but it is going to take some weeks to get here (it's from China).
                                      I tried to solder a 12m one and it showed up as an unknown device straight away. I really hope that this is the problem as I have re-soldered everything (apart from the switches and plugs) on the board and tested all of the caps for shorts so if that's not the problem it's probably the IC. Team Xecutor (the manufacturer of the device) are pretty strict when it comes to their devices so I doubt that finding the IC type will be easy.
                                      Anyway if anyone has any ideas on what to try tell me and I'll do it if I can.
                                      I'll keep you posted on what's going on with the repair.
                                      Last edited by reaper57; 01-20-2015, 04:20 PM.
                                      Keyboard not detected, press F1 to continue...

                                        Comment

                                        • Agent24
                                          I see dead caps
                                          • Oct 2007
                                          • 4939
                                          • New Zealand
                                          #11
                                          Re: Need help testing an oscillator.

                                          The crystal by itself doesn't oscillate. It needs extra circuitry to do so, the resulting circuit including the crystal is the oscillator.

                                          Sometimes the crystal and oscillator circuit is built together in one can which has 4 pins. These are quite large. Some SMD crystals are also in a 4-pin package, but the 2 extra pins are just for grounding the case.
                                          "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
                                          -David VanHorn

                                            Comment

                                            • reaper57
                                              Badcaps Veteran
                                              • Sep 2014
                                              • 216
                                              • Norway
                                              #12
                                              Re: Need help testing an oscillator.

                                              The crystals arrived a day ago and I changed the one one my programmer, now it's detected as it should be in windows and I programmed a xilinx chip with it, thank you to everyone for your time, assistance and information, I really appreciate it!
                                              Keyboard not detected, press F1 to continue...

                                                Comment

                                                • Agent24
                                                  I see dead caps
                                                  • Oct 2007
                                                  • 4939
                                                  • New Zealand
                                                  #13
                                                  Re: Need help testing an oscillator.

                                                  Good to hear
                                                  "Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
                                                  -David VanHorn

                                                    Comment

                                                    Previous template Next

                                                    Related Topics

                                                    Collapse
                                                    • lmcancu
                                                      LED Strip test points and testing?
                                                      by lmcancu
                                                      Hi is there a guide in this forum on how to test the LED backlight TV strips? I purchased an LED tester on amazon, but I am a bit confused on the test points and how to test the individual LEDs? I took apart a RCA 43" TV Rlded4331b. Please see attached pictures. I understand that all the LEDs are in series, but on these strips I don't see any individual test points for each LED? Any tips or guides?
                                                      Thanks in advance...
                                                      03-20-2023, 07:52 AM
                                                    • STKR123
                                                      The right BIOS Programmer - The right software (HP Elitebook 820 G1, 840 G2) no soldering, EC, DMI, ME
                                                      by STKR123
                                                      Greetings badcaps community,

                                                      I havent done this for a long time and want to start it all again, after some evil and annyoing illness.
                                                      So I apologize in advance, if some phrases might sound a bit like gibberish or illogical to you.

                                                      Im trying my best to fully describe what I plan to achieve and hope I was choosing the right sub-forum for my new adventure.

                                                      I have a Elitebook 820 G1 and a Elitebook 840 G2 here.

                                                      These ask for a password when entering the BIOS, but boot just fine from the internal SSD.

                                                      I learned that desoldering...
                                                      10-29-2024, 06:03 AM
                                                    • chth96
                                                      How Can I test PWM DM0365R?
                                                      by chth96
                                                      Hello
                                                      I have power adaptor(220V/input, 12V 1.2A/output) which has symptom of fluctuating output DC voltage between 11.5V-12.2V.
                                                      So I opened its plastic case and when switched it on, I heard constant tik tik sound from inside its PCB.
                                                      I measured DC voltage between negative and positive pin of the largest capacitor(400v 10uf) and it was measured contant 300V.
                                                      I also measured ESR value of all capacitors and I noticed that one of capacitor(KMG 16v 470uf), which located in the secondary side, have high ESR value(10 ohm),So I replaced it with same specification NXH capacitor....
                                                      06-18-2025, 04:14 PM
                                                    • khelane
                                                      test active pfc power with lamp test
                                                      by khelane
                                                      Hello
                                                      I have a big problem and that is that in some cases when repairing active pfc power supplies I cannot work with a test lamp. I can only get help with 5 volts standby and for starting and starting I have to work without a lamp and this way there is a possibility of parts exploding and other parts being added.
                                                      Sometimes with a multimeter test the problems can be reduced to some extent, but I had several cases that had to be tested on and online and recently two varistors exploded. They had terrible resistance because the power supplies were over 800 watts.
                                                      Is there a way...
                                                      06-03-2025, 01:00 AM
                                                    • chronic519
                                                      Mats / mods: detected and repaired GPU fault. Cant seem to test after!
                                                      by chronic519
                                                      Hello.

                                                      GPU came in, green lines. Spent lots of time using to get the Mats / mods drive working (found on youtube).
                                                      Found issue with a RAM block
                                                      Replaced, green lines gone.
                                                      Trying to test again, assuming getting the false positive. Originally had over 1K on a single bank. Now getting tosses low between banks.
                                                      Used a good card to test and same results low errors 32+.

                                                      I am just search for some form of command to do a full test on the GPU.
                                                      I just ran the mats command with my good GPU and passed after roughly 40 min.
                                                      The repaired one, ran...
                                                      05-20-2025, 07:56 PM
                                                    • Loading...
                                                    • No more items.
                                                    Working...