Mystery zener diode

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • joshnz
    Badcaps Veteran
    • Feb 2011
    • 969
    • New Zealand
    #1

    Mystery zener diode

    It is marked ZL30L I believe it is a 30 volt zener from the circuit it came from.
    it was working till I shorted the output
    Was outputting 28volts if i remember correctly.
    My pc
    CPU : AMD PHENOM II x4 @ 3.5Ghz
    MB : ASUS M4A89TD PRO USB3
    RAM : Kingston ValueRAM 16gb DDR3
    PSU : Cooler Master 850W Silent Pro
    GPU : ATI Radeon HD 6850
    Tags: None
    • joshnz
      Badcaps Veteran
      • Feb 2011
      • 969
      • New Zealand
      #2
      Re: Mystery zener diode

      Well I have put in 30volt zener but it is getting HOT so i guess the transister is damaged.
      you can see i put a watt meter in to monitor the zener looks fine.
      Attached Files
      Last edited by joshnz; 10-19-2011, 04:38 PM.
      My pc
      CPU : AMD PHENOM II x4 @ 3.5Ghz
      MB : ASUS M4A89TD PRO USB3
      RAM : Kingston ValueRAM 16gb DDR3
      PSU : Cooler Master 850W Silent Pro
      GPU : ATI Radeon HD 6850

        Comment

        • Longbow
          Badcaps Veteran
          • Jun 2011
          • 623
          • USA
          #3
          Re: Mystery zener diode

          What type of circuit is this? Is the cathode of the zener grounded, or does it go directly to the wattmeter? Easy enough to test both the zener and the transistor with a multimeter.
          Is it plugged in?

            Comment

            • joshnz
              Badcaps Veteran
              • Feb 2011
              • 969
              • New Zealand
              #4
              Re: Mystery zener diode

              Hi here is the actual circuit with the removed test equipment.
              The 2 transformers are actually one just could not find one in multi sim
              The zener shorted when I shorted the output waiting for replacement transistor to arrive as the old one does not give normal results.
              My pc
              CPU : AMD PHENOM II x4 @ 3.5Ghz
              MB : ASUS M4A89TD PRO USB3
              RAM : Kingston ValueRAM 16gb DDR3
              PSU : Cooler Master 850W Silent Pro
              GPU : ATI Radeon HD 6850

                Comment

                Previous template Next

                Related Topics

                Collapse
                • unimatrix93
                  TV backlight zener diode
                  by unimatrix93
                  Hello everyone, I'm repairing an LG TV backlight and I noticed some strange behavior when I touching the backlight strip with a missing Zener diode.

                  So I replaced the leds on the strips and they seemingly working fine, but soon as I touch the strip which has a missing Zener diode the whole backlight turns off for a few seconds and then turns back on.

                  Is this caused by the missing diode? If so what kind of zener diode should I use to replace it?.
                  ​​​​
                  The led strips has 9 6V leds.


                  ​​​
                  1 Photo
                  02-10-2025, 12:13 PM
                • hobostove
                  Corsair RM1000e - Help identify 5VSB Zener diode
                  by hobostove
                  Hey there guys. I've got a Corsair power supply that's come across my bench dead. I usually don't mess with power supplies, but it's a slow week so I'm giving it a whirl.

                  Taking it apart I heard a screw rattling around inside, and when I got it apart I found a couple blown components near what I think is the 5VSB area.

                  There's a 22ohm resistor that's melted and open, but it still has the bands.

                  The other part is a zener diode and it's top went to jesus, so I can't read the marking.

                  It looks like the diode connects the source and drain of a TNY284...
                  03-27-2025, 02:25 PM
                • debidoobs
                  Yamaha delay D1500, zener diode broken with no marking
                  by debidoobs
                  Hello,

                  im actually trying to save a d1500 delay from yamaha. I found the service manual but schematic is missing and BOM list is a bit unclear as components listed have no reference linked to the pcbs... In my case, one zener diode was broken (114 code on the pcb in attached file) and couldn't be repaired : it was a zener type package. In the BOM list i found 3 reference on this board : 1S555 (can be replaced by 1N4148), RD4.7EB2 (approx 5v rectifier), RD7.5EB3 (approx 7v rectifier)...

                  Actually the cathode goes to VCC of sram M5M5118P, without this diode missing, i have...
                  04-24-2024, 09:01 AM
                • caspian
                  What Zener Diodes on a Linear Power Supply
                  by caspian
                  Dear members,

                  I have a linear variable power supply with unknown brand name that I used for voltage injection.
                  Then it failed. I discovered that its transistors (Q1 and Q2) are shorted.
                  In addition, I discovered that its zener diodes are defective.
                  I can replace the burned transistors.
                  But I do not know the model of the zener diodes. the model number is not marked on the zener diodes.
                  Therefore, I cannot replace the zener diodes.
                  I do not want to test the zener diodes in a test circuit to discover their model or value.
                  no schematics are available...
                  05-26-2025, 12:38 PM
                • jm1234
                  T3D 21 - zener diode?
                  by jm1234
                  Hi,
                  I'm looking at the power source module of my Panasonic plasma TV TX-P42ST50. The TV goes into suspended state almost immediately and keeps flashing 6 times.
                  That zener diode is marked on the board with the diode sign (D204), that much I know. It seems to be open completely in both directions and its legs seem dark, as if it suffered some heat.
                  I'm having trouble finding a replacement. Does 21 stand for 21V?
                  The only other clue I have it is connected across 2 of the legs of a transformer (primary side).
                  Any idea how to find a replacement?
                  Thanks
                  ...
                  04-14-2024, 12:42 PM
                • Loading...
                • No more items.
                Working...