LG monitor repair advice

[mathsquid]

I'm trying to repair a monitor that has some bad capacitors in it, but I wanted to get some advice before I proceed.  There's some discoloration on the power supply circuit board, and there's some weird cracking in the solder behind two diodes.

The monitor won't switch on, but when I plug in the power supply board (while disconnected from the rest of the monitor), I get correct voltages on the header. I'm guessing this may be because there's no load, and that it can't provide enough current when under load.

I'm probably going to replace the three bad capacitor and just see if that fixes things, but any advice--especially about the cracked solder behind the diodes would be appreciated.

[wraper]

especially about the cracked solder behind the diodes would be appreciated.

That's not a cracked solder. Look how those look on the component side, those are metal inserts which add mechanical strength to the solder joints.

[SeanB]

I would replace all 6 Sucons ( appropriate name, SUSpect CONdenser) with new ones, and also replace the 2 small electrolytics on the primary side by the switching controller, they will be near to failure from being toasted by the hot parts near them, and will fail soon if not replaced. Resolder the 2 power diodes as well, they are rather well known to crack the solder joints by the rivets, so resoldering all those joints is a good idea, along with the joins on the power transformer and the mains connections as well.

[rfengg]

From your 1st pic , three electrolytics caps clearly show bulged tops.........surely the ESR and / or cap value must be out of spec on these........its best to change to all electrolytics just to be sure.

[Crazy_Engineer]

I would replace all 6 Sucons ( appropriate name, SUSpect CONdenser) with new ones, and also replace the 2 small electrolytics on the primary side by the switching controller, they will be near to failure from being toasted by the hot parts near them, and will fail soon if not replaced.

Follow this advice.  You don't want to have to open it up in a few months to replace the old capacitors you did not swap out.