Hello all, a bit new here so I apologize if this may belong in the newbie section instead, I'm not 100% sure of where exactly my skill level falls based on the community's standards.
Anyhow, a little over a year ago I acquired a pair of identical Dell D825HT monitors leftover from my university's math department cleaning their old equipment. One of them functions wonderfully save for being a tad dim and a bit off in the contrast area:
On the other one however I ran into some strange vertical circuit issues. As seen here, the image is not completely drawn before the beam returns to the top of the screen:
I did a little poking around with it in the past, but no extensive repair attempts. Now that we're all stuck inside thanks to the current epidemic I finally decided to completely commit to trying to repair it. After replacing all the capacitors on the mainboard (skipped the neckboard for now as parts on the mainboard are probably more important in diagnosing a problem like this, plus I didn't feel like desoldering the shielding and all to get to its parts), the image is complete when the beam returns to the top of the screen, but it still will not draw in the bottom 1/4 of the display, and the vertical adjustment controls on the front do not affect the image anymore:
Since I have two identical monitors, I can easily swap components between them as necessary for testing purposes, and have indeed swapped the tubes to make sure nothing is inconsistent with the behavior of the yoke, etc. In addition, while Dell has not provided a service manual for this display, I did find that its internals are near identical to one of Sony's own CPD-100ES monitor, whose service manual
can be found here. Any guidance on where to go from here would be appreciated. The only other concern in my situation is that I may be a bit short on test equipment to fully diagnose what's going on, so only my trusty old RadioShack DMM has become my faithful companion through this whole thing.
Home
Help
Search
Login
Register
