PB MLT168A for an Akai LCT2701AD LCD TV

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • orgud030364
    New Member
    • Mar 2014
    • 2
    • US
    #1

    PB MLT168A for an Akai LCT2701AD LCD TV

    I am new to troubleshooting TV's but had taken electronics courses in college 8 years ago and I am finally using my knowledge on TV's left behind in the garage by my growing children. I have a power supply board model MLT168A which was dead. Found several bad caps so I purchased the MLT168A kit and replaced the bad caps with the new. I finally got power output as following:

    5v = 4.97v (found in CON4)
    9v = 11.67v (found in CON5)
    12v = 11.67v (found in CON5)
    24v = 23.9v (found in CON7)
    24av = 20.8v (found in CON6)

    Voltage readings for 9v and 24av are incorrect.
    removed Zener diodes 4 and 5 which desoldering Zener diode 3 on one end and tested using a multimeter. Also desoldered three rectifiers without removing from board and also tested with the multimeter. All of these show they were good.

    what could be the problem?
    Tags: None
    Previous template Next

    Related Topics

    Collapse
    • 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
    • nev1001
      What zener diode might fix the sound on Maestro Mayhem gaming chair?
      by nev1001
      Hi, I'm looking for a bit of help trying to fix the audio unit from a Maestro Mayhem 4.1 gaming chair please.

      The chair has a few speakers and vibration motors. All was well, for a while, but now the sound is gone.

      It may be significant that I discovered my son was powering it with a 19V laptop charger when it should run on 12V - it did fully work, for bit.

      I think an issue could be a zener diode (or capacitor) which has shorted out.

      The board's bluetooth input still works, the vibration motors are working, so is the line out socket but not the...
      04-17-2025, 05:09 PM
    • sam_sam_sam
      NTE Electronics “NTE5251K” Zener Diode 9.1V @ 50W Do-5.5% Want to build a 9.1 output from a 9.6 lipo4 battery pack
      by sam_sam_sam
      I have bought this Zener Diode for this project what size and wattage resistor value do I need to use to get near 50 watt output
      I bought this from an eBay seller but unfortunately they only had one

      I bought three from Vetco Electronics these are Sylvania ECG5185A 9.1@10w A to Stud what size and watt resistor do I need to use to get near 10 watt output
      I bought three of from them to also make battery packs with this output power limit in mind

      I want to use this battery pack and turn it into a 9.1 output battery pack output to eliminate using 9 volt battery...
      04-23-2025, 05:50 AM
    • 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
    • Vincenzo2
      Element 32 inches tv (ELEFW328B) Unknown component: Diode or zener?
      by Vincenzo2
      My Element 32 inches tv (ELEFW328B) lost it's backlight (confirmed with a flashlight test) and the connector on the PCB (it has one board that has a processor chip, switch mode power supply, and backlight circuit) that has the two wires that go to the backlight LED strips has a very low voltage (28-29 volts) when turned ON, in my opinion.

      Started testing components and found an SMD diode or zener that is shorted (even zero fusing resistors read a few tens of milliohms, while this thing reads zero).

      I put some pictures here to show that it is labeled "M7"....
      09-07-2023, 07:43 PM
    • Loading...
    • No more items.
    Working...