12V rail is not on ?

Collapse
X
 
  • Time
  • Show
Clear All
new posts

  • bianchi77
    replied
    Re: 12V rail is not on ?

    I've fixed it,DONE

    Leave a comment:


  • budm
    replied
    Re: 12V rail is not on ?

    Since you bought some new rectifier diodes for replacement, did you test it with your tester to see if the Vf comes out the same as the spec sheet as tested per TEST CONDITIONS?

    Leave a comment:


  • budm
    replied
    Re: 12V rail is not on ?

    BTW, I am not the only that already pointed out to you about the test conditon:
    https://www.badcaps.net/forum/showpo...&postcount=144
    Quote:
    Originally Posted by bianchi77 View Post
    I got bad 2N60, C = 1.06 nF...on the datasheet, maximum = 350 pF
    That's because your transistor tester probably applies different test voltage and current.
    Also, you don't need a transistor tester to check transistor. Should be able to do this with a multimeter.

    Leave a comment:


  • budm
    replied
    Re: 12V rail is not on ?

    Originally posted by bianchi77
    Focus on this
    5.1.2 Measurement of NPN Transistor or N-Channel-MOSFET

    That will answer you about "TEST CONDITION"...if you 're not sure, it's up to you...
    https://www.badcaps.net/forum/attach...2&d=1476416557
    Look at the test condition.
    Well, did you look at the test condition as per spec sheet of the transistor and compare to what your tester using , since it is not the same then how can you are saying it is testing with the same test condition as the spec of the transistor was tested on.
    You are NOT comparing the same test condition, so if you believe your tester then you will probably believe you have lots of bad parts then. It is UP to you to believe your tester or not.
    Manufacturer put what test condition is done to provide the spec of the device, if you do not test at the same condition then the the end user cannot complain that the device does not meet the published specification, common sense.
    Test Condition:
    5V, 0.8A
    5V 4A
    5V 1mA

    So are you telling me that your tester is applying all those Voltage and current?
    Attached Files
    Last edited by budm; 10-14-2016, 07:25 PM.

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    Originally posted by momaka
    Out of circuit or in circuit. You always need to specify this.


    That's because your transistor tester probably applies different test voltage and current.
    Also, you don't need a transistor tester to check transistor. Should be able to do this with a multimeter.


    Like I said, I don't think anyone does. Or even if someone does, don't expect them to join this forum just to post it here. Work with what you have. This is a very very basic ATX PSU. If you don't understand how this PSU works without schematic, you need to step back and read/learn more about circuits and components.

    And again, I will ask you once more:
    PLEASE! Put all your 1-line, 1-sentence posts into a single post. We are already at page 8 here, and the thread is a mess. I am already forgetting what was tested and what wasn't. If this keeps up, I'm not going to be able to help you any further with troubleshoot this PSU.
    Yes I can do a test with multester, that's what I do usually and the component's bad...but sometimes the tester is not right as well...I want to compare with different tester....nothing to lose for me...
    Yes I keep learning about circuit and components that's why I keep fixing...
    I put 1 line, 1-sentence, because it's a progress...and I can't put all together at once...I've forgotten already if I try to remember what I had done...too many small things on fixing circuit...some kind of step what I had done..
    Last edited by bianchi77; 10-14-2016, 06:46 PM.

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    Originally posted by budm
    BTW, what happen to the bad IC with reading of 300 Ohms on the Open Collector output pin and GND?
    I've replaced it....

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    Originally posted by budm
    Can you show us how you set up your test equipment to do the test as shown in the spec sheet 'TEST CONDITIONS'?

    Remember how you are telling us the diode is bad because the Vf did not come out as shown in the spec and we had to explain to you how to read the spec sheet and how to test it per spec sheet? It sounds like you still do not understand or learn from that experience as to what the spec sheet is telling you.
    Focus on this
    5.1.2 Measurement of NPN Transistor or N-Channel-MOSFET

    That will answer you about "TEST CONDITION"...if you 're not sure, it's up to you...

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    Originally posted by budm
    You are joking, right?
    You mean your tester is putting out those exact test condition as shown in the spec sheet? How did you set up your tester to put out those Voltages and frequency? Do you really have that kind of test equipment? I thought you bought one of those $20 tester.
    I doubt that your tester can really do it as test condition.
    So where are the other two Capacitance readings?
    For a test...do we need to do all of them to decide the component is faulty ?
    one parameter is enough to decide...if you want to get all the parameters...you can have it but you need a better tester which expensive and only affordable by a big company which has a profit from it...
    for me I don't get any profit from it, only learning and curiousity...

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    Originally posted by budm
    You know what you can really do, get it over with and replace all the parts to get it working and put old parts back in one at a time until it stops working.
    Did you even try checking you new spare parts to see any of them meet the spec sheet based on the measurement using your tester?

    'I see a faulty on Q4,Q3,Q2,Q1, D9 board' based on your tester because the Beta of the transistor did not come out as shown in the spec sheet?
    I've checked all of the components one by one off board....
    What do you want to do for fixing anyway ? I want to know...replacing all the components by new one ? buy a new one then...easier...
    Last edited by bianchi77; 10-14-2016, 06:32 PM.

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    I've checked all of the components one by one off board....

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    Originally posted by budm
    Can you show us how you set up your test equipment to do the test as shown in the spec sheet 'TEST CONDITIONS'?

    Remember how you are telling us the diode is bad because the Vf did not come out as shown in the spec and we had to explain to you how to read the spec sheet and how to test it per spec sheet? It sounds like you still do not understand or learn from that experience as to what the spec sheet is telling you.
    Thanks for the comment....
    Have a read about test condition:
    http://www.mikrocontroller.net/artic..._.28English.29
    chapter 5...that's the way the transistor tested

    Leave a comment:


  • budm
    replied
    Re: 12V rail is not on ?

    BTW, what happen to the bad IC with reading of 300 Ohms on the Open Collector output pin and GND?

    Leave a comment:


  • budm
    replied
    Re: 12V rail is not on ?

    Originally posted by bianchi77
    yes it is with "TEST CONDITION"
    Can you show us how you set up your test equipment to do the test as shown in the spec sheet 'TEST CONDITIONS'?

    Remember how you are telling us the diode is bad because the Vf did not come out as shown in the spec and we had to explain to you how to read the spec sheet and how to test it per spec sheet? It sounds like you still do not understand or learn from that experience as to what the spec sheet is telling you.
    Last edited by budm; 10-13-2016, 10:06 PM.

    Leave a comment:


  • budm
    replied
    Re: 12V rail is not on ?

    You know what you can really do, get it over with and replace all the parts to get it working and put old parts back in one at a time until it stops working.
    Did you even try checking you new spare parts to see any of them meet the spec sheet based on the measurement using your tester?

    'I see a faulty on Q4,Q3,Q2,Q1, D9 board' based on your tester because the Beta of the transistor did not come out as shown in the spec sheet?
    Last edited by budm; 10-13-2016, 09:47 PM.

    Leave a comment:


  • budm
    replied
    Re: 12V rail is not on ?

    Originally posted by bianchi77
    yes it is with "TEST CONDITION"
    You are joking, right?
    You mean your tester is putting out those exact test condition as shown in the spec sheet? How did you set up your tester to put out those Voltages and frequency? Do you really have that kind of test equipment? I thought you bought one of those $20 tester.
    I doubt that your tester can really do it as test condition.
    So where are the other two Capacitance readings?
    Attached Files
    Last edited by budm; 10-13-2016, 09:50 PM.

    Leave a comment:


  • momaka
    replied
    Re: 12V rail is not on ?

    Originally posted by bianchi77
    D9 is short it goes 0 ohm on both direction...is it 1N4148 ?
    Out of circuit or in circuit. You always need to specify this.

    Originally posted by bianchi77
    I got bad 2N60, C = 1.06 nF...on the datasheet, maximum = 350 pF
    That's because your transistor tester probably applies different test voltage and current.
    Also, you don't need a transistor tester to check transistor. Should be able to do this with a multimeter.

    Originally posted by bianchi77
    do you have the schematic of ATX LEC-011 REV 1.2 ? Ritmo LPF2SS
    Like I said, I don't think anyone does. Or even if someone does, don't expect them to join this forum just to post it here. Work with what you have. This is a very very basic ATX PSU. If you don't understand how this PSU works without schematic, you need to step back and read/learn more about circuits and components.

    And again, I will ask you once more:
    PLEASE! Put all your 1-line, 1-sentence posts into a single post. We are already at page 8 here, and the thread is a mess. I am already forgetting what was tested and what wasn't. If this keeps up, I'm not going to be able to help you any further with troubleshoot this PSU.
    Last edited by momaka; 10-13-2016, 09:18 PM.

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    I see a faulty on Q4,Q3,Q2,Q1, D9 board = Y-B200ATX

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    on ATX LEC-011 REV 1.2 I've found 2SC2335 as a resistor...it's no more transistor on test device...

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    yes it is with "TEST CONDITION"

    Leave a comment:


  • bianchi77
    replied
    Re: 12V rail is not on ?

    do you have the schematic of ATX LEC-011 REV 1.2 ? Ritmo LPF2SS
    Last edited by bianchi77; 10-13-2016, 09:01 PM.

    Leave a comment:

Related Topics

Collapse

  • Victor Moreira Silva
    Acer Nitro 5 LA-L181p power LED turns on by 5 secs (Short on PCH rail?)
    by Victor Moreira Silva
    Hello everyone,

    I'm trying to repair my old Acer Nitro 5 (AN517-54-55T5). I've already bought a new laptop, so this is more of a learning project. For the experience, with no high expectations of success.

    Well, my decice specs are the following:

    Model: Acer Nitro 5 AN517-54-55T5
    CPU: Intel Core i5-11400H
    GPU: NVIDIA GeForce GTX 1650
    Motherboard: GH51G LA-L181P Rev:1c

    The symptom:
    When pressing the power button, the power LED lights up for about 5 seconds and then turns off. Initially, the issue was intermittent: sometimes...
    05-26-2025, 10:49 AM
  • grimacelord
    Xbox One S - 12V Rail Short - Q9F1 Keeps Blowing
    by grimacelord
    Hello,

    Have an Xbox One S here that has a short on the 12V power rail. There is no power, beep, or partial fan spin when connecting power cable.

    After diagnosing with thermal camera, Q9F1 MOSFET (NTTFS4C50N) is getting hot. When I remove this MOSFET, the short on the 12V rail disappears.

    I first replaced Q9F1 with one from a donor board and then partially reassembled the Xbox to test. When I plugged the power cord in, I got a partial fan spin and I thought I had fixed it, but unfortunately, the Xbox still did not power on. So I then disassembled the Xbox...
    10-24-2024, 12:31 PM
  • nagkiller
    Asus Geforce Cerberus GTX1050TI-O4G-DIS short circuit in the FBVDDQ rail
    by nagkiller
    Hello everyone!

    This grafic card came for repair, but when I connected it to the motherboard, the board would not start (short circuit in the 12V rail).

    After removing some PLs to isolate the short in the 12V rail, I got to PML1/PML2, according to the BoardView reference.

    Even injecting a voltage of 1V0 and a current of 3A in the FBVDDQ rail, for example, the voltage drops to 0V20 and none of the components heat up.

    The attached boardview file is very similar to this grafic card, which I am basing the repair on.

    I would like some...
    05-10-2025, 09:19 AM
  • joshAU
    Acer AN515-55-528T FH52M LA-J891P - Short ciruit after PQW1 MOSFET on +1.35VSDGPU rail.
    by joshAU
    Hi all.
    This notebook was showing no signs of life.

    I removed the FH52M LA-J891P mainboard and found that there was 19V at the DC jack.
    However there was zero volts on the two PRB2 and PRB46 resistors immediately after the two polarity protection MOSFETs (PQB11 & PQB12).

    If I remove the PQW1 MOSFET, the 19V rail starts working, and I can turn on the unit - at least I get the fans, and the power light comes on, when I simulate the power button being pressed. No display.

    I tried replacing the MOSFET with a new one, but again no voltage on the...
    05-29-2024, 12:33 AM
  • techrepairheide
    Gaming laptop Clevo NH79EP with short on 5VS-rail
    by techrepairheide
    Hello,

    first of all I want to apologize for my bad English, but I try to give my best.

    Customer brought me a laptop, which is charging the battery (when the dc-jack is connected) but don't power up when the power-button was pressed down. Only the white LED lights up, and you can hear a short noise in same interval when power-button was pressed and hold for longer timer. The customer changed already battery and dc-power-adapter.

    For this laptop the correct shematic is the service manual "Clevo NH50ER NH57ER NH50EPS NH57EPS - 6-71-NH5S0-D02 Schematic"....
    10-13-2024, 02:49 PM
  • Loading...
  • No more items.
Working...