Acer X193+ monitor repair

tagMost of my equipment had the sense to wait until after I had moved from the US to Madagascar to fail, but not this Acer Monitor. I had picked it up cheap as a bundled deal with a desktop computer in 2009 from  New Egg Computer, and it failed early in 2014. I had purchased two identical systems at that time, and the other monitor is still working without a problem.

The monitor wasn’t entirely dead – the power LED is still lit up and when power was applied, the word “Acer” would appear for about a second, and then the screen would remain black. This suggested that most of the monitor was working. Since we were packing up for the move, I thought it would be better to box up the monitor and tackle it on the other end after I had a workshop set up. A year and a half later, it came back out of the box.

There are many reports of monitors in this family failing, and almost all of them come down, as you’d expect, to electrolytic capacitors that have gone bad.  There are two boards inside the monitor, a power supply board and a logic board with the VGA and HDMI connectors. To delve down to the power board, you need to unscrew the stand, pry apart the plastic shell, and remove the metallic tape that holds a metal cover over the boards. There are numerous descriptions of how to pry apart the case, but I found that just working it with a screw driver in each hand sufficed and did not result in any of the plastic tabs breaking off.

taped

I was surprised that the metal cage over the boards wasn’t secured with screws or some kind of mount. The metallic tape seems fine for mitigating EMI, but I wouldn’t really consider it structural. The tape has to be peeled off carefully where it covers thin cables. One cable runs down to  a thin PC board with tactile switches on it at the lower edge of the monitor, the other is the bus that goes to the screen. That cable has to be disconnected to get at the sub-boards. A plastic bar that holds the cable in place flips up, and the cable slips out.

This delicate ribbon cable emerges from metallic tape and connects to a tab on the top edge of the back of the monitor.
This delicate ribbon cable emerges from metallic tape and connects to a tab on the top edge of the back of the monitor.

The power board is held in position with four screws, and it must also be disconnected from the logic board by pulling the two boards apart. I tested all the caps in the power section – none showed voltage, but I shorted them anyhow for safety. Two caps were obviously bad, both were 220 uF, 35V. The other caps looked okay. I replaced one of the bad ones with a 220uF, 50V cap, but I had only one of those in the junque box. The other I replaced with a 330uF, 50V cap. I don’t have an ESR tester, so I could not evaluate the remaining electrolytic caps in circuit, but I could at least tell that they had not failed short.

caps
The two shortest electrolytic caps were the problem: one by itself at far right, the other on the right side of a cluster of three. The tops of these two 220uF caps were bulging and discolored.

I buttoned up the metal enclosure, plugged in the monitor and a computer’s VGA output. The monitor lit up like new and worked fine. I put everything else back into place, which means getting the tape job right. The buttons on the bottom and alignment of the power socket and video input jacks relies on the metal box being correctly centered.

I verified that the monitor works now with either VGA or HDMI input and it has been put into service on the bench.

working

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