Help With ATX smps

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • papabol_24
    New Member
    • May 2010
    • 2

    #1

    Help With ATX smps

    Hello there, i have some low end ATX smps boards lying around so i thought that i could use them in some other way so i decided to set it up as a power supply for my 2 linksys routers and bandluxe 3G router all running at the same time, it worked for abt a year then one evening it suddenly went dead, all preliminary checks were ok, fuse not blown, rec diodes ok, primary caps ok, switching transistors ok, sec rec diodes ok and sec filter caps ok, i noticed that my 5vsb voltage was too low, abt 1.4 volts only, checked the schematic and the 5vsb ckt has 2 transistors, one for the 5 volts and one for the startup power of the TL494 chip that should be 10 to 12 volts (measured from a spare board) both transistors are ok, when i remove the VCC pin of the TL494 the 5vsb and the 12 volts supply of the TL494 chip became normal, i removed the chip and tested it on a good board and grrrrr the TL494 chip is working, can pls somebody help me, confused and currious
    Attached Files

Related Topics

Collapse

  • sam_sam_sam
    TL494 PWM Controller Module Booard to control a SMPS switching power supply are they available for this purpose
    by sam_sam_sam
    I have seen some board on eBay and Aliexpress but I have not seen any for SMPS switching power board modules I would like to build one if I can not find one that is already made

    Dose anymore known if there is such a module and where would I find some

    While searching this topic on google I found this

    https://www.badcaps.net/forum/troubl...anything/page3

    I have read through this I have some switching...
    09-16-2024, 05:39 AM
  • Loretto
    Samsung SMPS BN44-00339A
    by Loretto
    Hi all,
    this unit comes from a samsumg LCD TV LE32C530F1W which stopped working after making a strong noise like something was exploded inside of it.
    I opened it and found that fuse FP801S was blown, capacitor CP814 was completely disintegrated and MOSFET QP801S was shorted.
    I replaced all of them and instead of the fuse I connected a 100 Watt bulb. Then, without connecting it to other TV boards, I switched it on, but the bulb begun to blink.
    I thought that maybe the bulb was somehow interfering with the normal operation of the power supply, so I replaced it with a fuse,...
    03-29-2025, 08:30 AM
  • Loretto
    Samsung SMPS BN44-00339A
    by Loretto
    Hi all,
    this unit comes from a samsumg LCD TV LE32C530F1W which stopped working after making a strong noise like something was exploded inside of it.
    I opened it and found that fuse FP801S was blown, capacitor CP814 was completely disintegrated and MOSFET QP801S was shorted.
    I replaced all of them and instead of the fuse I connected a 100 Watt bulb. Then, without connecting it to other TV boards, I switched it on, but the bulb begun to blink.
    I thought that maybe the bulb was somehow interfering with the normal operation of the power supply, so I replaced it with a fuse,...
    03-28-2025, 10:28 AM
  • dkneyle
    Onkyo DX-V500 Laser Disc Player - weird SMPS fault
    by dkneyle
    This relic from a technology path that came to a dead end (but still has historical interest) was brought in with a dead SMPS, which is based around a MK1210 device. I got it going after a battle. It seems to have a strange design - if it's not getting feedback that the secondary is OK it cause the big FET to go into full conduction and overloads resulting in a blown fuse at best or something worse! I'm using a Dim Bulb Tester (70W/230V) which thankfully has saved the day a number of times whilst repairing.

    Now, it loads a CD OK. The motor voltage output (which is built onto the SMPS...
    02-01-2022, 02:08 AM
  • shamsudeen
    Hi, Can we use SMPS Bench Power Supply for Laptop troubleshooting?
    by shamsudeen
    Hi all, I just need to know that, can i use SMPS type power supply to test and short circuit detection on a laptop motherboard?
    I saw 95% of repair guys are using only Linear bench power supply. linear bench power supply is pricy, thats why i planned to get one SMPS supply.

    i know that in linear power supply the noise will be very low comparing to SMPS supply....
    07-19-2025, 07:14 AM
  • Loading...
  • No more items.
Working...