Vendex Headstart VGA M-888-VC

[chjmartin2]

Hi,

I don’t know specific forum for a monitor but this one goes with a 286 so seemed ok. Anyway, the monitor seems to work great but it keeps shutting off on me, and if I wait a minute and turn it back on it seems to go back on. Anyway, got any ideas on how to fix? Could it be as simple as the switch? I have a chicken stick so not worried about cracking it up to work on it. Here is a video of the behavior.

Thanks,

Chris

 

[Robin4]

Think changing out the capacitors.. Its a power issue..
I also have a monitor that powers on, and after 1-2 minutes suddently its powers off again..
Powerboard needs a recap.

 

[chjmartin2]

I wonder which one is bad. Doh!

 

[chjmartin2]

Sadly I recapped the entire powerboard and I have the same issue. I tested the switch and it doesn’t seem to be that as it goes back on and off seemingly randomly. There are some additional caps on the main board. Cycling the power switch doesn’t seem to matter at all and hitting the side does nothing. Really bummed because the picture is fantastic when it is on and I am sure it is one small component. I need to figure out if the whole power board is shutting down - the power LED shuts off too. Feels like power issue. I really wish I were smarter…

 

[chjmartin2]

I found the "service manual" but it is just badly scanned schematics and a parts list. This monitor is actually a Samsung CQ4551. The power supply acts very strangely. The output voltages are fine until it "clicks" off and then they are all weird. Oddly, if I run the power supply without load it doesn't turn off - in fact even if I turn off the power switch the circuit is live. I was told elsewhere that this is a thermal issue but I have reflowed the solder on the entire power supply. This project is killing me because it is in the way of others. I am close to giving up sadly.