29 Ekim 2016 Cumartesi

Samsung SyncMaster 932Bplus monitor repair

I have decided to repair my old Samsung Syncmaster 932BPlus monitor when it went dark. It is a nice monitor I like because it has a nice rectangular shape, which is better than the wide screen monitors available nowadays. Initially it would intermittently show images for brief periods then turn to normal display mode. However at the end it stopped working. It would go dark after power up with only the blue soft button being lit. It was time to repair. It was an obvious capacitor failure problem, the type of repairs you find on internet abundantly especially on eevblog. So this is an "eevblog" type repair;) Nothing special only capacitors to replace.

 I cracked the case open.

At least 3 capacitors are seen bulging. But the others had to be replaced too, as it turned out later they had an ESR value above the maximum limit.

 The large filter cap of 100uF 450V had a high ESR value too and indeed it is very slightly bulging.

I used that cheap Chinese ESR-meter to measure the ESR value of the caps, I also used the DE-5000.

I did not have the exact capacity and voltage values in stock and did not want to wait for Monday to go downtown to purchase the right stuff, so I used the oversized caps in the pics. I had therefore to put them in the horizontal position so that the board fit in its protective metal case. The replacement caps are cheap ones (except the large black 100uf 450V one) that I purchased 4 years ago. I am not sure of their quality but we shall see how long they last. Anyway now I unplug the monitor when I do not use it. Because the soft power button does not disconnect the device from the mains.

I needed a 47uF 50V cap whereas I had at best 22uF 63V ones, so this is the result...

The culprits.

After replacement of the bad caps, I test the monitor for the last time before I close the case.

Here you are.