Mitsubishi 55857 started squealing on left audio

bpschoch · Joined: 26 Dec 2007 Posts: 2

My Mitsubishi WS55857 started to squeal on left channel. At the same time the convergence went off. I'm guessing iit's a power supply problem. Has anyone seen this before and point me in the right direction?

minnie · Joined: 18 Aug 2005 Posts: 2880 Location: Hell

Squeal is probably coincidental. Replace the 2 STK392-570's to start.

bpschoch · Joined: 26 Dec 2007 Posts: 2

I took the board out and it looks like an electrolytic cap must have died due to fluid on the board (near the area of the STK392-570's). Fluid has spread around so I can't tell which one yet. I'm going to check with meter when I get a chance.

minnie · Joined: 18 Aug 2005 Posts: 2880 Location: Hell

Fluid is from one of the picture tubes leaking. (Common on this model.) All you can do is damage control. Clean the board w/damp cloth w/warm water. Let it dry. Get as much of the coolant off as possible. Make a deflection board (Cardboard) to shield the boards. (Drip shield) In other words start looking for a new set. Look closely at the other boards to see if coolant got on them too.