Philips 42FD9944 powersupply failure

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • PowerAmpFreak
    Badcaps Veteran
    • Feb 2010
    • 982
    • Sweden

    #1

    Philips 42FD9944 powersupply failure

    Hello everyone,

    Got a struggling older Philips plasma, model 42FD9944.
    During poweron it crackles and pops from the SMPS, I can read a somewhat unstable PFC voltage of around 390VDC, jumps a few volts up and down.
    VA and VS does not start anymore, recently tried to start up those, but not reach their correct magnitudes.

    Suspect a bad caps SOMEWHERE, there are hundreds in this set.

    Please check the attached pic and let me know if you know what to check.
    Attached Files
  • PowerAmpFreak
    Badcaps Veteran
    • Feb 2010
    • 982
    • Sweden

    #2
    Re: Philips 42FD9944 powersupply failure

    Any advice?
    Have to go through the pcb with freeze spray. Hairdryer didn't reveal anything.

    Comment

    • freakaftr8
      Badcaps Legend
      • Oct 2012
      • 3743
      • USA

      #3
      Re: Philips 42FD9944 powersupply failure

      Crackle and popping is not a good sign, where in the SMPS is that coming from? Primary or secondary side?
      Did I leave the soldering iron on?

      Comment

      • PowerAmpFreak
        Badcaps Veteran
        • Feb 2010
        • 982
        • Sweden

        #4
        Re: Philips 42FD9944 powersupply failure

        It's hard to determine which side crackles. I suspect the crackles are, simply, the PFC trying to regulate but the DC/DC is jumpy and won't present a smooth load.

        Comment

        Related Topics

        Collapse

        • alro7779
          Philips 32PFL4901/F8 BA4GF0F0102 2 Not getting standby led
          by alro7779
          Hello, guys!

          The same 32" Philips TV I was having video issues, but now I don't have standby led at all. Someone here shared with me the schematic of the power supply, and checking the voltages, I see right after the resistor R604 I'm getting 1.6 v which is too low for enabling the Gate of the Q601 mosfet (the diagram says 4.2). On the R614 resistor I'm getting 181 V in and 117 V out, then through R603 I'm getting the same 117 V in and 59.9 V out, finally getting the latter voltage in the R604 BUT getting just 1.6 V out, which is the voltage that goes on to the Gate of the Q601...
          09-14-2025, 12:25 AM
        • G33RT
          Philips 8200 series 65PUS8204/12 stuck at Philips Logo
          by G33RT
          Philips 8200 series 65PUS8204/12 stuck at Philips Logo, it does not reboot it just stays on the logo.

          It does power up when pressing the power button.

          I already try the power button while plugin the plug with no result.
          Also put the latest firmware autorun-TPM191E_R.001.004.100.000.upg on a MBR/FAT32 USB stick at USB port2 with no result either.

          Could this be an PSU or eMMC issue ?
          07-19-2025, 03:43 AM
        • double_DD
          Philips curling iron - is this a common AC cable?
          by double_DD
          Hi all,

          Wife has 2 Philips hair curling irons half defective - after learning how they're supposed to work and testing them, it turned out that both have defective power cables, and both on the same place; broken wires due to wire bending.
          As they were both relatively easy to disassemble, and cables are plugged not soldered (as they can rotate in the handle), I was sure it would be easy to find replacements. But - NO! I'm unable to find anything similar on ebay or Aliexpress.

          Not sure if this is something Philips proprietary, or a standard, but the cable plug...
          08-18-2025, 10:04 AM
        • janos6662000
          Philips 47PFS7509/12 LCD TV problem
          by janos6662000
          Hi

          I have here a Philips 47PFS7509/12 LCD TV which came to me with a weird problem : without signal i could access menu, make a factory reset, access menus, etc.
          When i applied cable signal to check image, i had normal picture, but TV was restarting.
          I downloaded original firmware and applied the update, but the problem remained.
          From a colleague i received a "factory package software" which is a lot bigger.
          I made another firmware update, but still did not solve the problem.
          Somewhere on the way the error got worse, because at the moment the...
          08-12-2025, 12:54 PM
        • Sus256
          HISENSE 65E7KQ PRO - no boot
          by Sus256
          Hi all!

          HISENSE 65E7KQ PRO
          RSAG7.820.13512 - chassis
          MT9618BAATAB - cpu
          RSAG7.820.12059 - power
          HD650Y3U77 - panel
          KLM8G1GETF - emmc

          The TV does not turn on, the standby indicator is on. All voltages are present.
          Emms is dead. Not readable, not detected.
          Replaced emmc.
          But with another dump there is no launch

          Terminal log

          UART
          <
          AC_ON
          RPMB key is not yet programmed

          HASH1_VERSION=0x00000000 64bit
          E-B
          FDE enabled
          layout pattern onebin by SAR7,0...
          06-01-2025, 02:11 AM
        • Loading...
        • No more items.
        Working...