Viewsonic VX2835WM

[Drellis]

This display took a while to fail. Would have to press power button multiple times to get it to turn on. It finally stopped working all together. Seemed like a power supply failing, so in searching for a replacement power supply, and some troubleshooting information I found the world of bad capacitors which eventually led me here.

I tested the power button, and it functions properly. All my caps look good, which as I understand doesn't really mean much so I thought I'd post pics of the boards, and get your opinions on what additional testing/troubleshooting I should attempt before ordering and replacing some/all of the caps to see if I can resurrect this display. I've included shots of the main board as well.

It's a difficult aspect ratio to replace, so getting it working again would be awesome, as it's by far my preferred aspect ratio to work in.

Thanks for the advice, and all the help you do for everyone on this forum. It's incredibly impressive.

[stj]

Re: Viewsonic VX2835WM

i fucking hate that type of design, the psu just gets cooked!

from the foto the 2 1000 uf 35v caps are gone, the tops are rounded slightly.
i recommend replacing *all* the electrolytic caps on that psu.

[budm]

Re: Viewsonic VX2835WM

https://www.badcaps.net/forum/showthread.php?t=11329
Same power supply as used in HANNS-G

[Drellis]

Re: Viewsonic VX2835WM

i fucking hate that type of design, the psu just gets cooked!

from the foto the 2 1000 uf 35v caps are gone, the tops are rounded slightly.
i recommend replacing *all* the electrolytic caps on that psu.

That's interesting… They looked fine to me. Any way for you to indicate what tipped you off? I'd like to be able to identify bad caps better in the future if I can. Also would you include everything under the heat sync that's soldered to the board? Specifically the 420v 150hf cap?

Also: Do you think this is because of shitty caps, or bad PCB design? I have no idea what to expect out of this hardware after I (hopefully) get it working again.

[stj]

Re: Viewsonic VX2835WM

the top of caps should be dead-flat, look at the top of the big ones in the 4th pic.

it's a bad pcb design, caps should not be next to or under heatsinks or close to hot parts.
that design is a joke, they just packed it all in as tight as they could!

as for the 420v cap, normally i would ignore the main cap, but being under a sink, i'd meter it.

[stj]

Re: Viewsonic VX2835WM

btw, there are a few bad solder joints on the psu, and the main board also has caps right up against regulators that will cook them!