Viewsonic VA1930WM repair

Yet another dead monitor made its way into the Kuzyatech lab. A 2007 vintage Viewsonic VA1930WM monitor that stopped turning on.The symptoms were classic- power on light cycles on and off, but the screen stays dark,while a faint repeating squeal can be heard from the unit. Sounds very much like that Samsung  LN32A330 I fixed recently. Time to take it apart! First take out two screws on the back of the case. Then pry ot the cover hiding the top of the stand and undo four more screws. Now pry the two plastic halves apart using a suitable plastic tool. Once the shields were off, we are left with a classical picture- a power board and a video processing board. My bet was on the power supply, so we take it  out first:

Why do all of these look the same?

After a brief look around, the culprits are pretty obvious- the usual caps in the usual location are bulging:

Baaad caps

The larger one is a 1000uF 25V and a smaller one 1000uF 10V. Both are made by Su’scon of Taiwan and claim to be 105C rated. Measurements show leftover capacitance in 200uF range for both. Replacing both with similarly sized Nichicon parts brought things to life pretty quickly.

It's alive! Muar pattern is a side effect of trying to photograph the LCD and is not visible to a human eye

So there goes another monitor saved from the landfill. Sounds like it’s time to stock up on low ESR caps for the next time!

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