Viewsonic NX2232w with no video or audio

[gnuorder]

I have a Viewsonic NX2232w that seems to power up fine but I never get video or audio through the tuner or VGA. When I plug it in, I get an orange light on the power button. When I turn it on, I get the blue light, the three birds appear then the screen goes blank. After that, none of the switches respond, or if they do I can't see, and I can't power it down. After testing it. I notice the heatsink on IC301 is cold. Don't know the part number because of the heatsink but the main board is part number 6201-70220000001.

It seems the main board is working because it shows up on my laptop hardware when I connect it. Also there is a red LED on the main board that lights up. Also it seems the power board is working because the main board powers up and I can see the birds so the backlight works. I see no obvious damage on either board except some slight heat damage around the AC input components. I tested voltages past that and they looked fine. Any ideas on what the problem could be or where I can check?

[CapLeaker]

Re: Viewsonic NX2232w with no video or audio

The main board has tons of capacitors and a few voltage regulators. I would start there. Other than that, you'd need a new main board.

[gnuorder]

Re: Viewsonic NX2232w with no video or audio

The caps all look good though that doesn't mean they are. Trying to identify the regulators and measure then. Do you happen to know what's under the heatsink at I202? I assume its a regulator based on the need for the heatsink.

[gnuorder]

Re: Viewsonic NX2232w with no video or audio

The caps all look good though that doesn't mean they are. Trying to identify the regulators and measure then. Do you happen to know what's under the heatsink at I202? I assume its a regulator based on the need for the heatsink.

Hmm, what happened to the edit button?

Anyway, I tested I202 and it acts like a 1.75v regulator. pin 1-3 voltages are 0, 1.78, 5. There are three 7585-3.3 regulators that all measure 3.28v. Then there is one I can't find. It's I304 and the numbers on it are 1084 0729AL and the pins 1-3 voltages are 0, 1.24, 3.05.

ID' I304 as an AIC1084 1.5, 1.8, 2.5 or 3.3v regulator with a 5v input. I'm beginning to suspect there is a problem there.

Also found the edit button on this post but not my others. Not sure if that's a bug or a feature.

[gnuorder]

Re: Viewsonic NX2232w with no video or audio

Found two more 1117 regulators, I104 and I105. Voltage at the pins are 0,2.44,5 and 0,3.2,5. Forgot to mention yesterday I measured power from the power board on standby and on. Pins 1-9 on are o,5,0,0,5,5,3.2,0.1,25.3 and standby 0,5,0,0,5,5,3.2,2.3,26.3. Pin 8 is the back light on line.

[gnuorder]

Re: Viewsonic NX2232w with no video or audio

I got a used main board on ebay that is suppose to be good. It still does not come on but with some differences. if the boards are cold, it doesn't power on at all. standby orange LED goes out. If I warm the boards up with a hair dryer it will power on but still no picture and menu, source, etc buttons don't work. With this board I can power it on and off. my old board I couldn't power off after I powered it on. Also pin 7 on the power connector is labeled ADJPWMA in the schematic and measures 3.27 and pin 8 is bclon like I suspected.