Thank you to the guys at HEGE supporting Badcaps [ HEGE ] [ HEGE DEX Chart ]

Announcement

Collapse
No announcement yet.

IISonic IIEM989 weird problem

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    IISonic IIEM989 weird problem

    I just picked this one up today. Monitor will not work unless one of the buttons (anything except Power) is kept pressed. No obvious bad caps in the power supply or on the logic board (although they're all Lelons), voltages are all in check, inverter ok, lamps ok.

    I'm suspecting a bad EEPROM but i don't have a programmer for those... and even if i did i don't have a dump to write to it. Any ideas before i order a new logic board? I found one here: http://www.ebay.co.uk/itm/55-L21V2-0...item5889130fd7
    Originally posted by PeteS in CA
    Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
    A working TV? How boring!
    Tags: None
    #2
    Re: IISonic IIEM989 weird problem

    It pays off to triple check... I checked all wires that go to the keypad and on the 4 buttons i got 3.3v when they are not pressed, only on the power button i had 0.3v... So i disconnected the keypad and the power button line also went to 3.3v. Momentarily shorted it to ground - the monitor came on and STAYED on.

    Looks like i just have a bad power button. I have a few handy, gonna replace it and let you know how it went.
    Originally posted by PeteS in CA
    Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
    A working TV? How boring!

    Comment

      #3
      Re: IISonic IIEM989 weird problem

      Fixed, albeit in a different way. The power button exhibited no appreciable leakage when measured with a multimeter set on resistance, so i used a 1k resistor from the 3.3v rail to make a better pullup. Works fine.

      The voltage does however fluctuate from 3.2v to 2.5v on the button so there is a bit of leakage there (while the 3.3v rail is rock solid), but that's not a problem - anything between 2.0v and 3.3v is "high" in TTL logic.
      Originally posted by PeteS in CA
      Remember that by the time consequences of a short-sighted decision are experienced, the idiot who made the bad decision may have already been promoted or moved on to a better job at another company.
      A working TV? How boring!

      Comment

      Previous template Next
      Working...
      X