GD235HZ - No power no light. Completely dark.

G2idlock
G2idlock Member Posts: 1 New User
edited February 27 in 2020 Archives
Looking for a service manual for this particular monitor... even some schematics for the logic board.

I've checked the PSU and am getting 5v output on the leads to the logic board and the signal dies there. So it's not the PSU. It's on the logic board. If anyone's encountered this problem or has the schematics/service manual I'd greatly appreciate the help.

Btw I'm like 8 years out of warranty and outside the US.

Answers

  • billsey
    billsey ACE Posts: 34,219 Trailblazer
    edited June 2020
    The service manuals aren't public, so we can only share snippets from them. Can you get to an OSD menu at all? Does the LED light at all, if so which color? There should also be a 22VDC from the power board in addition to the 5VDC.
    Click on "Like" if you find my answer useful or click on "Yes" if it answers your question.
  • facundoen
    facundoen Member Posts: 2 New User
    I have the same problem! It initally happened intermittently. I would really appreciate if you could send us the schematic and references for the power board, and maybe the logic board. as you cannot send us the service manual. Some components on the power board seem burned out, and the markings on them have become unreadable (some resistors). Many thanks! 
  • stratcat
    stratcat Member Posts: 3 New User
    billsey said:
    The service manuals aren't public, so we can only share snippets from them. Can you get to an OSD menu at all? Does the LED light at all, if so which color? There should also be a 22VDC from the power board in addition to the 5VDC.
    Mine won't turn on either. No Led, no light of any kind. I have 5VDC on 2 of the pins but you mentioned 22VDC and that I don't have that leaving the power board. Visually both boards look ok so any assistance or schematic snippets would be helpful.
  • stratcat
    stratcat Member Posts: 3 New User
    *Bump* 

    Anyone?
  • billsey
    billsey ACE Posts: 34,219 Trailblazer
    @stratcat you should really be on your own thread... Which specific model do you have? It's not easy to decipher schematics with the ones they put in the service guides, the large sheets is reduced to a small page so the lettering is a bit problematic. There is the AC input, then a transformer then a full wave rectifier, then another more complex transformer which has +5V and +22V. It looks like the 22V test point is somewhere near R818...

    Click on "Like" if you find my answer useful or click on "Yes" if it answers your question.
  • stratcat
    stratcat Member Posts: 3 New User
    billsey said:
    @stratcat you should really be on your own thread... Which specific model do you have? It's not easy to decipher schematics with the ones they put in the service guides, the large sheets is reduced to a small page so the lettering is a bit problematic. There is the AC input, then a transformer then a full wave rectifier, then another more complex transformer which has +5V and +22V. It looks like the 22V test point is somewhere near R818...

    Thanks. I had a short to ground @ pin 6 of I207. I wasn't seeing 1.26v on pin 6 which led me to FB307 and eventually the BGA chip. I re-flowed the chip and poof it's working again. We'll see how long it lasts...
  • billsey
    billsey ACE Posts: 34,219 Trailblazer
    Sweet! Glad you got it sorted. :)
    Click on "Like" if you find my answer useful or click on "Yes" if it answers your question.

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