Re: Vizio VX37L Different PCB No Picture, Orange-to-White LED, Will not turn off

1A would be pushing it, yes. The AMC1117 is rated for 0.8A (max on a heatsink).

Note to others considering this repair: all of the following is somewhat sketchy, and best practice would be a small heat sink on this part, soldered directly to the board. It's my TV though

Using 0.8A as a worst-case current an AMC7588 in TO-263 with a 45ºC/W Tja is under Tj=150ºC even over 70º ambient with zero air flow. There is a small but perceptible convection current in there, and...

Re: Vizio VX37L Different PCB No Picture, Orange-to-White LED, Will not turn off

That was the proof of concept LOL I didn't leave it like that! While it was dangling at the ends of those wires with the TV working, the regulator barely got warm. The wires are thick enough to conduct "some" heat (they were hard to tin with the small iron) and I cut them to ~1-2cm, just barely long-enough to let me solder them in place.

The stock part on the stock heat sink was obviously deficient IMO. From my reading of the datasheets, this regulator is rated for free-air...

Re: Vizio VX37L Different PCB No Picture, Orange-to-White LED, Will not turn off

Well I don't have any spare 1117s laying around but . . .





tom66 thanks for your help!

Funny what happens when everybody's bandgap references are working. This TV was $$$ and it needed a $0 repair. Thats crazy. No user serviceable components inside . . . or not thanks Jesus!

I have a Vizio VX37L with the typical "LED goes orange to white, no display, will not turn off with power button" failure. BUT. The circuit board is not the one everyone knows and loves(?), it is a different version. The tuner is on the opposite end and there isn't a U33 on the PCB at all.

The grounding screws are tight, as are the connectors. 12V and 5V are present at the main board and fuses are ok.

The 1117 I know, but I'm not sure what exactly the other devices with the same package are. Fortunately they all seem to be putting out a voltage matching...