Announcement

Collapse
No announcement yet.

User Profile

Collapse

Profile Sidebar

Collapse
Avatar
ragis
Senior Member
Last Activity: 03-07-2024, 01:41 PM
Joined: 03-26-2013
Location: Sofia
  •  
  • Filter
  • Time
  • Show
  • Source
Clear All
new posts
  • ragis
    replied to Hitachi 43HAK6150 No Booting
    in Troubleshooting TVs and Video Sources
    Okay...
    Continuing with the measurements from the power block diagram.
    All voltages are present:

    U104 - [B]1.1V[/B]
    U154 - [B]1V[/B]
    U100 - [B]3.3V[/B]
    U130 - [B]1.8V[/B]
    U140 - [B]1.2V[/B]
    U101 - [B]5V[/B]
    U153 - [B]3.3V[/B]
    U125 - [B]1.5V[/B]​

    I think i'm getting close to the conclusion that either the eMMC is bad or the processor is not working...Okay...
    Continuing with the measurements from the power block diagram.
    All voltages are present:

    U104 - [B]1.1V[/B]
    U154 - [B]1V[/B]
    ...
    See more | Go to post

    Leave a comment:

  • ragis
    replied to Hitachi 43HAK6150 No Booting
    in Troubleshooting TVs and Video Sources
    Hello again,
    No result by now...
    The mainboard has all it's voltages:
    3.3V, 5V, 12V
    Measured U100 which is the DC-DC converter from 12V to 3.3V
    Checked the voltage on T-Con mosfet Q151- it goes 12V on pin 4, but there is no 3.3V on the Base of Q147 - it has only 200mV.
    I can't trace from where should it get these 3.3V....
    See more | Go to post

    Leave a comment:

  • ragis
    replied to Hitachi 43HAK6150 No Booting
    in Troubleshooting TVs and Video Sources
    Hello again,
    Today I remembered that i've forgot to check the T-Con board, and as I expected there is no VCC on the fuse, or on the LVDS cable.
    I've tried to heat up the CPU and see if there is any change at all, but without success
    I've checked the mainboard "schematic" which I believe is not the full - [URL="https://www.mikrocontroller.net/attachment/557249/vestel_17mb170-idtv_sm.pdf"]link[/URL] and also traced the pins from the LVDS which are leading to some testpoints and the traces maybe are going directly to the CPU.
    So if the problem is with the...
    See more | Go to post

    Leave a comment:

  • ragis
    started a topic Hitachi 43HAK6150 No Booting
    in Troubleshooting TVs and Video Sources

    Hitachi 43HAK6150 No Booting

    Greetings,
    A friend of mine gave me this VESTEL crap, since it was not working.
    But actually it is working - the backlight is ON, but it seems like the firmware is bricked or gone bad - I have no info if it was flash, but as i assume it is not.
    I checked the voltages of the PSU board - they seems OK, also checked the voltages on the Mainboard - it has power to USB ports(tried to put a USB stick but it is not recognizing it, the stick led don't light up, but i can charge my phone from it).
    Since this is an eMMC flashchip can it be bad ? In order to flash it i will also need...
    7 Photos
    See more | Go to post
  • ragis
    replied to 2xCH3041AHT PSUs problem
    in Troubleshooting Power Supplies and Power Supply Design
    Re: 2xCH3041AHT PSUs problem

    Thanks, for the help !
    As you suggested it was this little bastard 47uF/50V after replacing it on both everything works like charm !
    Thanks again, best regards
    ragis
    See more | Go to post

    Leave a comment:

  • ragis
    replied to 2xCH3041AHT PSUs problem
    in Troubleshooting Power Supplies and Power Supply Design
    Re: 2xCH3041AHT PSUs problem

    Thanks guys for your reply i appreciate that,
    @budm: KA3842 the resistance between 7 pin (VCC) and 5 pin (GND) is 600R if i reverse the leads(red probe on 5pin and black probe on 7pin) if the leads are red to 7 pin and black to 5 pin i get 1 on my DMM or 0L for all( i test it on diode mode) this is the measurements for the working and not working psus( i think that they are ok)
    I didn't replaced the small cap, but i will maybe this week and i will post the results.
    For the 3 diodes on the cold side i tested them in diode mode and they...
    See more | Go to post

    Leave a comment:

  • ragis
    started a topic 2xCH3041AHT PSUs problem
    in Troubleshooting Power Supplies and Power Supply Design

    2xCH3041AHT PSUs problem

    Hi folks, i have a problem with two CH3041AHT PSUs they had bulged caps and i recaped them successfully.But now the first one starts after maybe 1min or so..
    The second one don't even starts...
    I measured them and on the first it has all the outputs like +5, -5, +24.
    The big cap 100uf/400v is 330V on both PSUs, but on the second not working the V is lost somewhere around the little filter cap 47uf/50V i measured it and it's 0V and on the other psu(the working one) is 14V
    The PWM IC is KA3842 and to go in to switch on mode it needs 16V.
    Thanks for your help, best...
    See more | Go to post
  • ragis
    replied to JVC AV 2110EE dead after turn off
    in Troubleshooting TVs and Video Sources
    Re: JVC AV 2110EE dead after turn off

    Ok, some news guys found that the PTC(posistor) is burned up, it says:
    96724 PH98146 and it's 3 pin
    I have 2 pin posistor solder it and nothing happens again..
    Should i purchase the same PTC or i can bypass it somehow to turn the tv on... ?
    See more | Go to post

    Leave a comment:

  • ragis
    replied to JVC AV 2110EE dead after turn off
    in Troubleshooting TVs and Video Sources
    Re: JVC AV 2110EE dead after turn off

    I don't have remote to switch it to standby, and yes if i unplug it it goes dead right away without warming period...
    See more | Go to post

    Leave a comment:

  • ragis
    started a topic JVC AV 2110EE dead after turn off
    in Troubleshooting TVs and Video Sources

    JVC AV 2110EE dead after turn off

    Hi folks, today i have a problem with an old CRT TV
    It turns on but after turn off it's completely dead, even if i unplug it and then try go turn it off it stays dead.But after 2-3 hours unplugged it can turn on again and then dies after shutdown...
    Here are the specs:
    Chassy: CKF0708-CH2-1
    STR F6653
    TB1226EN
    M37212M6
    AN5265
    LA7840
    D1878

    I replaced:
    C942 - 100uF/160V
    C924 - 100uF/25V
    C945 - 1000uF/16V (replaced with 2200uF/16V)
    STR F6653 with a new one..
    And also resolder all ICs and...
    See more | Go to post
  • ragis
    replied to 2SK1445 alternative
    in General Electronics Technical Discussion
    Re: 2SK1445 alternative

    Thanks stj, i found another alternative [b]STP10NK80ZFP[/b]
    Here they have it online and will go to the store to get it Re: 2SK1445 alternative

    Thanks stj, i found another alternative [b]STP10NK80ZFP[/b]
    Here they have it online and will go to the store to get it     Re: 2SK1445 alternative

    Thanks stj, i found another alternative [b]STP10NK80ZFP[/b]
    Here they have it online and will go to the store to get it
    See more | Go to post

    Leave a comment:

  • ragis
    replied to 2SK1445 alternative
    in General Electronics Technical Discussion
    Re: 2SK1445 alternative

    Thanks for the reply and datasheet stj but could you suggest any ?
    See more | Go to post

    Leave a comment:

  • ragis
    replied to 2SK1445 alternative
    in General Electronics Technical Discussion
    Re: 2SK1445 alternative

    Thanks but i'll wait for it for a month...
    The stuff from China is taking too long to come
    See more | Go to post

    Leave a comment:

  • ragis
    started a topic 2SK1445 alternative
    in General Electronics Technical Discussion

    2SK1445 alternative

    Hi, folks

    This time i'm struggling to find a cross reference to this N Channel Mosfet:
    [B]K1445[/B] which is [B]2SK1445[/B] in the datasheets

    Here in our stores there is no such thing so i'm searching for an alternative.
    Thanks in advance !

    Best regards, ragisHi, folks

    This time i'm struggling to find a cross reference to this N Channel Mosfet:
    [B]K1445[/B] which is [B]2SK1445[/B] in the datasheets

    Here in our stores there is no such thing so i'm searching for an alternative.
    Thanks in advance
    See more | Go to post
  • ragis
    replied to ASUS VK191S - no power
    in Troubleshooting Computer Displays
    Re: ASUS VK191S - no power

    OK, monitor repaired !!!

    The problem was in the logic board SPI flash IC - SST25VF010A
    I used a flash bin from VK191D and it worked
    Thanks again for the replies and help from stj and budm
    As stj recommended i resoldered the whole PSU.

    So the solution is to reflash the IC !
    Thanks again and best regards, ragis !
    See more | Go to post

    Leave a comment:

  • ragis
    replied to ASUS VK191S - no power
    in Troubleshooting Computer Displays
    Re: ASUS VK191S - no power

    Ok, any other sugestions ?
    See more | Go to post

    Leave a comment:

  • ragis
    replied to ASUS VK191S - no power
    in Troubleshooting Computer Displays
    Re: ASUS VK191S - no power

    Just one simple question:
    on the logic(main) board there are 2 voltage regulators U1 and U2
    U1: pin3(input) - 4.74V pin2(output) - 3.28V pin1(adjustment) - 0V
    U2: pin3(input) - 3.28V pin2(output) - 1.78V pin1(adjustment) - 0V
    They are both 1117 but i don't know if they are fixed or adjustment the marks are:
    U1: 17-33
    U2: 17-18

    Thanks again
    See more | Go to post
    Last edited by ragis; 06-01-2016, 12:36 PM.

    Leave a comment:

  • ragis
    replied to ASUS VK191S - no power
    in Troubleshooting Computer Displays
    Re: ASUS VK191S - no power

    Ok, so i added 3 1K resistors to the 3 pins and then without logic board i plugged the monitor in AC and the backlight started blinking.I think that means the inverter is OK.But why it can't power on the monitor and even go to stand by mode... What can i do now ? Thanks again for the help to check the inverter
    See more | Go to post

    Leave a comment:

  • ragis
    replied to ASUS VK191S - no power
    in Troubleshooting Computer Displays
    Re: ASUS VK191S - no power

    The client told me that there was a surge shock and the monitor stopped working i can't locate any burned component .. Can be the logic board get demaged.And last thing how can i test the inverter ?
    See more | Go to post

    Leave a comment:

  • ragis
    replied to ASUS VK191S - no power
    in Troubleshooting Computer Displays
    Re: ASUS VK191S - no power

    The solder joints are ok, it seems like that from the flux i used around the pins
    But i can resolder them if you think there is a problem, could you be so kind to show me the cracked ones ?
    See more | Go to post

    Leave a comment:

No activity results to display
Show More
Working...
X