Hyvision by Megavision MV220 LCD monitor goes blank after 0.5-1 second
I need some help with my PC LCD Hyvision by Megavision MV220 monitor.
I am an electrical hobbyist that very much enjoys fixing things. I can solder/unsolder reasonably well and have a good understanding of electrical circuitry (although by trade am Mechanical Engineer).
History/problem statement:
Purchased monitor in 2007 and has been working flawlessly until 1 month ago. 1 month ago monitor would turn on for 1 sec show the computer screen and then go blank. I would reset the computer (thinking that it maybe the PC fault) and the monitor screen would come on. This lasted for about 2 weeks and then after reset it would not come on. So after trial and error found out that if left idle for about 15-30 after start and then reset LCD monitor would turn on. 1 week later and the monitor required several resets/restarts for it to come on until it would not come on at all. I connected the monitor to my laptop and the same thing happened.
To summarize the monitor comes on for 0.5 - 1 second and then goes blank. I can see the computer screen and everything is normal (when I turn on/off the monitor) but it only lasts for 0.5 - 1 second before going blank.
What I have done:
• Measured output of external power supply with a meter and am getting 12.11V. External power supply is rated for 4.16A @ 12V DC (as shown in attached photo)
• Connected the Monitor with different power supply (lab PS high quality) and the same issue occurs. PS was measuring only 0.6A draw @ 12.11DC setting.
• Opened up the monitor and checked the main board and inverter board. No signs of burns, boards look clean, no signs of capacitor bulging or leakage as shown in the attached photos.
From what I have read it seemed logical (and cheap) to replace all caps and retest. Before I did this I was hoping someone with experience could tell me where to start with replacement first (identify which caps could be the culprit and replace first) or any tests that I can do to identify if any other part may be problematic.
Tools available:
Digital multicenter, RC tester (can measure up to 20uF capacitance), oscilloscope, Adjustable lab power supply (Max 5A @ 30V), breadboard, Soldering Iron, wires, connectors and a wide variety of parts (resistors, caps, inductors etc).
I can provide more info if I have missed describing what is needed to identify the issue.
I thank you in advance for taking the time to help in this matter.
I am an electrical hobbyist that very much enjoys fixing things. I can solder/unsolder reasonably well and have a good understanding of electrical circuitry (although by trade am Mechanical Engineer).
History/problem statement:
Purchased monitor in 2007 and has been working flawlessly until 1 month ago. 1 month ago monitor would turn on for 1 sec show the computer screen and then go blank. I would reset the computer (thinking that it maybe the PC fault) and the monitor screen would come on. This lasted for about 2 weeks and then after reset it would not come on. So after trial and error found out that if left idle for about 15-30 after start and then reset LCD monitor would turn on. 1 week later and the monitor required several resets/restarts for it to come on until it would not come on at all. I connected the monitor to my laptop and the same thing happened.
To summarize the monitor comes on for 0.5 - 1 second and then goes blank. I can see the computer screen and everything is normal (when I turn on/off the monitor) but it only lasts for 0.5 - 1 second before going blank.
What I have done:
• Measured output of external power supply with a meter and am getting 12.11V. External power supply is rated for 4.16A @ 12V DC (as shown in attached photo)
• Connected the Monitor with different power supply (lab PS high quality) and the same issue occurs. PS was measuring only 0.6A draw @ 12.11DC setting.
• Opened up the monitor and checked the main board and inverter board. No signs of burns, boards look clean, no signs of capacitor bulging or leakage as shown in the attached photos.
From what I have read it seemed logical (and cheap) to replace all caps and retest. Before I did this I was hoping someone with experience could tell me where to start with replacement first (identify which caps could be the culprit and replace first) or any tests that I can do to identify if any other part may be problematic.
Tools available:
Digital multicenter, RC tester (can measure up to 20uF capacitance), oscilloscope, Adjustable lab power supply (Max 5A @ 30V), breadboard, Soldering Iron, wires, connectors and a wide variety of parts (resistors, caps, inductors etc).
I can provide more info if I have missed describing what is needed to identify the issue.
I thank you in advance for taking the time to help in this matter.
Attached Files
- Im sorry I must have missed your previous posts. Hopefully that will keep it going a bit longer - perhaps consider replacing any other caps of same make.
But today, I’m making an exception here. Why? No idea. Perhaps only because the repair details are still “fresh” in my head… which is ironic, given this is a 16 year old monitor that hardly anyone will care about today. It is new to me, though. 
I picked it up last November from someone on my local Craigslist. It wasn’t very close to where I live, but was close to a family friend that I had to go visit anyways. So after watching the posting on Craigslist for a few weeks and seeing it getting...
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