Sanyo STK 392 040 Convergence AMP burns out in HDTV application

[LB]

Any reason for this IC to burn out? Replaced carefully, enough heat sink
grease. Ran one week.

L

 

[Christian Treldal]

Den Thu, 21 Apr 2005 21:28:37 -0500. skrev LB:

Any reason for this IC to burn out? Replaced carefully, enough heat sink
grease. Ran one week.

L

Bad caps at it's output. Test with an ESR meter. or simply change them.

 

[Leonard Caillouet]

Cheap chinese replacements? Where did you get them?

Is there significant dc offset on the inputs? Used too much heat sink
grease?

Leonard

 

[Art]

Agreed, order exact manufacturer replacment, check the associated low value
resistors, and supply voltages.

 

[LB]

I'm pretty sure the replacements were original Sanyo. They looked
identical to the originals in the set, with the date code above the
STK number, and some alphanumeric numbers on the aluminum in the back.
I think the cheap Chinese parts look slightly different.

All the low value resistors check out good too. I'll have to check the
supply voltages when the set is fired up. I don't have the print for
this set, but I would presume the positive and negative rails are the
same voltage.

I'll try to check for DC offset on the inputs. I wouldn't think there
would be any, but I'm only guessing.

On this Mistsubishi both modules are held in place with a single screw
in the center and a piece of spring steel. Maybe I can drill holes and
use more screws.

Thanks for the help.

LB