Vizio VX42L HDTV10A not coming out of standby

[Eureka]

Have a problem with my Vizio VX42L HDTV10A that I am seeking guidance on.

The problem:

On a cold start up the tv will not turn on. I can press the power button on the tv or the remote and nothing at all happens. The orange vizio standby light is on and does not blink or flicker, glows steady.

If I unplug the tv from the outlet for several seconds, plug it back in, it will start normally. I usually have to repeat this several times. The Vizio standby light changes from orange to light blue and the tv turns on normally and will run completely normal.

Strangely, If after the tv has been running and is shut off, it will restart normally if it is tried within a hour of being off. Otherwise the unplugging procedure.

What I've done:

First tried plugging into the outlet directly, bypassing the surge protector. Took the back off the tv and and checked for loose connectors, bulged caps, bad solder, burned components, ect. I did find a tipped connector on the powersupply. Removed both the mainboard and the power supply board and did further visual inspection. I could not see anything suspicious. Believing that a increase in temperature might be handy to know for diagnosic
purposes, I used a hair dryer to warm the power supply board and the main board to see if it would reset. It still did not start without the unplugging procedure. Also tried the reset button on the main board. The tv is currently back together and not functioning any better. Considering using it as is until it dies completely.

My thoughts (guesses) to this point:

As far as I know, a signal is sent from the main board to the power supply when the tv is started telling it to come out of standby. Something is failing on the mainboard to provide the proper signal when the tv has been off for a long time. Unplugging must be resetting it. It could be the start up circuit in the power supply also. But, I kind of doubt it. Would like to narrow it down to which board at a minimum. Hopefully, someone has seen this problem before.

My limitations:

I only have a basic electrical knowledge and a simple DMM. I know, mission impossible, but I am determined!


Power supply:
0500-0505-0450
2010517CH331600

Main board:
3642-0242-0150 (4A)
05ML0682G05764A
CSD:03642-0242-0395 ----is this a substitute board number?

Thanks,
Dave

[cadiman]

Re: Vizio VX42L HDTV10A not coming out of standby

Sounds like you need some recapping on the power supply.

[Dgtech]

Re: Vizio VX42L HDTV10A not coming out of standby

Post a picture of this set open. In a second picture, one of the power board in question.

[cadiman]

Re: Vizio VX42L HDTV10A not coming out of standby

This has the heat sinks covering capaciters on the power supply board. I would start with those. I have done a few of these. This is a good beginner board. I have had the same problem with other L/g power supplies with the same issues you are having.

An esr meter would help, but you will most likely see the capps that are bad on this board.

[Eureka]

Re: Vizio VX42L HDTV10A not coming out of standby

Here's a couple pics:

[hoadle]

Re: Vizio VX42L HDTV10A not coming out of standby

I had Vizio VW42LHDTV1OA can turn on the logo Vizio form Orange to White color & back light on but no logo or blue screen
Find VIZIO 3642-0102-0150 MAIN UNIT bad but still T/S maybe U33?
http://cgi.ebay.com/VIZIO-3642-0102-...46087977104581

[hoadle]

Re: Vizio VX42L HDTV10A not coming out of standby

I found that thread about U33: https://www.badcaps.net/forum/showthr...&highlight=U33
from Mr. kingofcoins
U33: Top No # AMC1117 Where I can buy this parts?
Bottom No # F0734J
Thanks

[PlainBill]

Re: Vizio VX42L HDTV10A not coming out of standby

I found that thread about U33: https://www.badcaps.net/forum/showthr...&highlight=U33
from Mr. kingofcoins
U33: Top No # AMC1117 Where I can buy this parts?
Bottom No # F0734J
Thanks

That's a 'jelly bean' part, available from many manufacturers. They are available in both fixed and variable outputs, so make sure you order the correct one. The fixed output ones have the output voltage on top. This particular one is made by Add Microtek Corporation. An equivalent might be the LM1117MP-ADJ

PlainBill

[hoadle]

Re: Vizio VX42L HDTV10A not coming out of standby

Thanks PlainBill i will order

[Eureka]

Re: Vizio VX42L HDTV10A not coming out of standby

Thanks for the additional information. Since my original posting I have replaced the power supply board with a used one, as it cost only $45. It was cheaper than replacing caps and/or buying even a cheap esr meter. Of course with my luck, it did absolutely nothing to fix the tv. So, that brings me to the main board. I can still start it with the unplugging procedure and probably will do nothing until I get sick of unplugging it, or it craps out completely. At that point I am thinking of a used board and having it rebuilt
by ModusLink PTS. Looks like they would rebuild it for $100.

[hoadle]

Re: Vizio VX42L HDTV10A not coming out of standby

because U33 need 3.3 V adj maybe (LM1117MP-3.3 or LM1117MP-3.3/NOPB/BKN)?
I will order both fixed and variable outputs LM1117MP-3.3 & LM1117MP-ADJ

[hoadle]

Re: Vizio VX42L HDTV10A not coming out of standby

I parts come in, I replace U33 finally is TV isworking
Thanks all you guy hepl me out

[Eureka]

Re: Vizio VX42L HDTV10A not coming out of standby

Hoadle,
I am very curious, exactly what partnumber did you get (fixed or variable output) and where?

Thanks,
Dave

[hoadle]

Re: Vizio VX42L HDTV10A not coming out of standby

Thanks for PlainBill his give me parts # LM1117MP-ADJ
but I bought 10 LM1117MP-ADJ ($0.5083/each) & 0 LM1117MP-3.3 ($0.6847/each) at
https://avnetexpress.avnet.com/store...1&listIndex=-1
but LM1117MP-3.3 can't return that why I didn't buy, just bought LM1117MP-ADJ (fix)
I replace with LM1117MP-ADJ on U33
Now my TV working again

[Eureka]

Re: Vizio VX42L HDTV10A not coming out of standby

Thanks!
The cost is low enough for me to give this a try.

Dave

[hoadle]

Re: Vizio VX42L HDTV10A not coming out of standby

Here picture my Tv after done replace U33

[PlainBill]

Re: Vizio VX42L HDTV10A not coming out of standby

Thanks!
The cost is low enough for me to give this a try.

Dave

Note that the output voltage of U33 was wrong. Replacing U33 if the output voltage is correct is pointless.

PlainBill

[Eureka]

Re: Vizio VX42L HDTV10A not coming out of standby

Yes, I agree. I did see the original post and I do have a meter.

Thanks,

Dave

[PlainBill]

Re: Vizio VX42L HDTV10A not coming out of standby

Yes, I agree. I did see the original post and I do have a meter.

Thanks,

Dave

Common, give me a break here!!! I'm curious, did you test the output of the regulator?

Understand my background. For over a decade I supervised (and trained) a group of electronics technicians. My goal was to teach them to troubleshoot logically. When they were hired most were more comfortable with troubleshooting by hunches, by shotgunning, by history ("Joe fixed one by replacing IC18, I'll replace IC18" even though the symptoms are different), or by replacing the largest component (a $400 A/D converter).

PlainBill

[Dgtech]

Re: Vizio VX42L HDTV10A not coming out of standby

I'd have to say I'm guilty of swapping a component out on a hunch but it usually would either have the same symptoms of the previous failure or simply be a matter of having the part in front of me so, what the heck, change it. For me personally, being a field systems tech (vs. a bench tech) for so long, I'm not where I'd like to be with component troubleshooting without schematics. If I have a schematic, I'm ok - just ok, lol.