VO47L FHDTV10A no picture on 2 of these sets

[mu2]

Re: VO47L FHDTV10A no picture on 2 of these sets

I should have been a little more specific about the Chipquik alloy. I believe I ordered a kit that had some tacky flux and a short length of the low temp alloy. Search the web and go to the Chipquik website. They have some videos showing smd ic removal. My experience with their product has been very good and as long as the ic doesn't have a ground pad on the underside the removal is very simple.
Good luck with the ic replacements.
I just hope you also don't also have a problem with the main boards.

Mike

[djrobbaron]

Re: VO47L FHDTV10A no picture on 2 of these sets

So I get back from Christmas Eve family stuff out of town at 10PM last night to find my Digi-Key order sitting on the front porch...
(They kick so much butt at packaging and shipping. Always a pleasure.)

As I stated before, I goofed the order and didn't get the ChipQuick desoldering alloy. I was also running on about 2.5 hours sleep from the night before, but I had to at least make an effort to get a big screen on the wall before the family woke up for Christmas morning. Eyelids propped open with toothpicks, led flashlight between my teeth, crappy 5X magnifier alligator clipped awkwardly off the side of the flashlight, I flipped on the Hakko FX888 and went to work.

I have a hot air gun with no nozzle attachments that I considered for the two 5.4mmX13.6mm - 32 pin surface mount IC's removal, but they sit between 2 horizontally mounted caps and a minefield of surface mount resistors/what-nots that I could just see floating away in a river of molten disappointment (no matter how creative I could get with origami style aluminum foil tenting).

I checked the back of one of the new parts for a ground pad and was relieved to find none. While looking at these minuscule new things I realized that there is a TINY space where the legs of the IC angle from their chip exit down to their 1/4 eyelash size pads. Line up 16 of those spaces and you have a channel of sorts. Off I ran to find the roll of 30 gauge magnet wire I thought I might have. I was able to thread the wire down the channel keeping the angle low to the board and angled wide at the end of the 1st and 16th pins so as not to stress the connections and destroy the solder pads or peel up the traces. With the slightest bit of outward tension on the wire, I tinned the iron and did a sort of reverse drag solder with 63/37 at 250°F. I couldn't have been more relieved as the wire slipped through leg by leg. I wasn't sure if the solder had reattached after the wire passed, but wasn't about to pry on it to see. I did the same thing on the other side and she lifted right off! Fluxing and alcohol for clean up and I had a beautifully made bed for the new part to rest on. I have to say the hardest part about the whole process was getting that itty bitty part centered perfectly on all 32 pads to tack down. It constantly wanted to slide off the paper thin pads which was like a cliff to the legs of the IC. Once I got it tacked though, smooth sailing.

I went ahead and replaced all 4 surface mount MOSFETs on each inverter regardless of the way they tested as suggested. This would have been a big pain if I hadn't already run the gauntlet with the IC's.

I cleaned up all the solder joints and have to say that after close inspection, I honestly thought mine looked better than the manufacturer's originals. So, it CAN be done.

With a sick feeling in my stomach, I popped the inverter boards in and plugged in the power. I nearly cried tears of joy when I turned the set on and saw the backlight turn on across the back. I walked around the set prepared to see the input label and/or no signal on the screen...
Are you kidding me?! No nice blue screen, instead, nearly a third of the screen was covered with a "puddle" that had a nice star shaped fracture at it's center. Nobody mentioned that little morsel when I obtained the sets.

Ok, there's still hope. The other set is still sitting there and it's only 2AM..UGH!

I moved the PSU and the inverters over to the second set, secured them, plugged in, made the same trip around to survey the screen. Perfection!

So by about 5:30AM I had an assembly screw for every day of the year back in it's threads, set on the wall, screen cleaned, faulty 32" Insignia off the coffee table, and universal remote programmed.

I could NOT have done this without you guys. Especially you Mike. Thanks to you guys and my impeccable balance on this insanely slippery and steep learning curve, the kids and the wife were THRILLED! If I ever get some sleep after Christmas with the in-laws this afternoon, I'll decide whether to part the cracked set out or keep the repaired boards for backup. Then where to start on new threads for the 50"plasma, 26"LCD, or 32"LCD? I'm hooked!!

Oh yeah, I also repaired a $30 POS DVD player during the parts shipping interim thanks to general info I've picked up here during this process.

Thank you, thank you, thank you!!!!
Happy holidays to you if you're celebrating any!


Rob

[djrobbaron]

Re: VO47L FHDTV10A no picture on 2 of these sets

BTW, I'd love to be able to clean this thread up a little for anyone who may use it in the future. Is there any way to get temporary moderator privileges so I can pull offsite linked pictures and such? I'm sure I haven't seen the last of the issues with this set and since we're keeping this one, I'd love to keep the thread updated and as clean and useful as possible now that I know how.

[mu2]

Re: VO47L FHDTV10A no picture on 2 of these sets

Rob,

I'm happy that you got the set to work. It is an addictive, happy feeling when those backlights come on!
I have also had what I thought was a simple power supply repair turn bad when I found that the screen was damaged upon power up. Frustrating after you diagnose and order parts, etc. It wasn't a Vizio.
My experience with Vizio sets is that they are either easy to repair or impractical. I seem to see a fair amount of main board issues where some chips fail and run very hot. Now if I determine the fault is on the main board I look at the underside of the boards to see if there is discoloration and usually stop.
Take care.

Mike

[freakaftr8]

Re: VO47L FHDTV10A no picture on 2 of these sets

Good job! Nice Christmas present as well! Sorry to hear the other screen was damaged thou. Its a risk we take in tv repair I guess.

[stinger381]

Re: VO47L FHDTV10A no picture on 2 of these sets

I just repaired this same set by doing the repairs that MU2 mentioned on page 1. My inverter boards had bad caps and then I found the power supply was not sending power to the inverter boards due to a bad cap there. I replaced them all and the tv gave me the blue screen I was looking for. It seems this is a typical repair for this tv. The hardest part for me was finding the caps locally. I ended up ordering them all online. Good luck for those that try this repair in the future.