CurtPalme.com Home Theater Forum

[macgyver655]

With the seemingly high demand for repair and with the consent of the boss, I am offering board testing and repair for the Vizio VX37L.

I'm starting with this model because I already have a test unit. I will add more models as I see fit and acquire an appropriate test unit.

I already have successful repairs on this model. Fees will be very minimal during startup and will be discussed on individual basis.

You must be able to remove your boards and send them to me.

Comments welcome for other known problem models.

[crtcrt76]

Hi Macgyver,

We have a V042LFHDTV10A that just went dark and it's only ~11 months old. Sound works, backlight and blue screen with input show up perfectly, but for only 2-3 seconds. You can hit power twice (turn off, then turn on), and this process will repeat.

5, 12, and 24v supposedly work as they should, amber logo light turns to white and stays white until you turn it off (which cuts audio), so mainboard seems to be fine, and I would think the PS is also. No visible evidence of blown caps on the inverters or main PS. The internals pretty much look like the thread about "Black Screen Of Death" regarding the GV47L where you helped quite a few people.

Disconnect Master or Slave inverter HV lead, and corresponding side is dim for the 2-3 seconds. Blue LED on the master inverter slowly fades out when the backlight goes out.

I have reflowed solder on all the larger parts (Caps/Transformers/Coils) on these three components, even cleaned up a mistakenly almost bridged connector for the ribbon cable to the Slave inverter... no changes.

PS Board is DPS-260HP-1
M Inverter - LG 6632L-0470A for panel LC420WU5 (REV 1.2)
S Inverter - LG 6632L-0471A

Have not properly tested the transformers on the inverters, but none look different than the other in terms of discoloration, I assume I have to take these components off to compare them properly? Would the lights even light up if they were bad?

I have seen repair kits for the inverters, for an IC and what look like 4 transistors - is this feasibly what could be wrong?
Here is a link - http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130446882338

My issue seems very much like satpro92's at this link (his PS ended up being bad, and possibly the wrong part from the factory o_O ). My voltages stay within 1v of what they are supposed to be throughout the power on sequence and for at least 30 seconds after it's been turned off and the lights gone out, did not test longer.

http://www.tv-forums.com/cgi-bin/gforum.cgi?post=59941

Called Vizio, and they told me it only had a 90 day warranty to begin with which angered me - they are hard to get a hold of, and have the customer service skills of a turnip. No indication of being a refurb when we got it (a gift from the inlaws). A local store still has refurb's with this exact model number with a -RB appended to it, but it looks nothing like my TV. front looks about the same except for a silver stripe at the bottom, but back is completely different, all the connections are at the middle/bottom, while 2 of my HDMI and analog connections are on the right.

Got any parts you want to sell, or offer a repair on this model? I'm more of a CRT guy, but this was our bedroom TV since Christmas last year.

tl;dr - Vizio went fizio.


EDIT: It might be a VO42LFHDTV10A not V042LFHDTV10A, just looked at the back again, and the O looks more circular than the 10a part.

[crtcrt76]

Very strange, vizparts.com lists the inverters with an "N" instead of an "A" in the part #, and what looks like hand soldered jumper modifications to the traces to some of the pads and possibly the IC. Wonder why?

http://www.vizparts.com/product_detail.php?pid=2029#

And they too have a small solder bridge between pin 6 and 7 for the brown ribbon connector for the slave - bottom left corner (that I removed thinking it was a mistake)
https://www.vizparts.com/admin/download.php?f_id=1819&w=1600&h=1600

Then if you keep looking, you will find that they also list a completely different inverter for the same model TV (mine looks like the ones above btw, not like this single board with 4 transformers). Found one on eBay too saying this part was pulled from the same tv model number, but couldn't possibly be fit into mine... unless this one is hidden somewhere as a third inverter.

6632L-0481a
http://www.vizparts.com/product_detail.php?pid=1945

Is Vizio really this inconsistent with internals and even external looks for the "same" model TV?

[WanMan]

[Curt Palme]

crtcrt, I can't add much except for this: If the set worked for 11 months, then forget about 'wrong' boards or components installed, this is a part failure. (see my many posts about all current electronics lasting 2-5 years, you're a 'bit' under.

I'm not sure I understand the problem with the set, please clarify: When the set goes out, does the sound die as well or does it stay? DOes the backlight go out, but if you shine a flashlight onto the LCD screen, can you still see the image? Or, does the backlight stay on and the video image goes off, leaving a blank but backlit screen?

If the sound dies as well, I'd suspect bad solder joints on the processor chip, a common problem on many LCD TVs, and the set is a writeoff.

If the backlight stays on and only the video dies, I suspect the same thing, and it's a writeoff.

If the backlight goes out and the video stays on the unit, you have hope.. maybe. I have a slew of computer LCD monitors where the backlight dies after a few seconds. Power supply voltages are OK. I suspect changed impedance of the backlight driver transformers or bad tubes in the backlight itself, but haven't had a chance to compare a bad backlight monitor with one that works, as to swapping parts between the two. About all you can do is an impedance check on the transformers, comparing one to the other to see if they change significantly. There's some good information at www.badcaps.net forum here:

http://www.badcaps.net/forum/forumdisplay.php?s=d64decd9c98790870e0061e9f96a20bf&f=31

I personally haven't worked on a Vizio, so my info is pretty generic, but it could be helpful.

[Curt Palme]

crtcrt, I can't add much except for this: If the set worked for 11 months, then forget about 'wrong' boards or components installed, this is a part failure. (see my many posts about all current electronics lasting 2-5 years, you're a 'bit' under.

I'm not sure I understand the problem with the set, please clarify: When the set goes out, does the sound die as well or does it stay? DOes the backlight go out, but if you shine a flashlight onto the LCD screen, can you still see the image? Or, does the backlight stay on and the video image goes off, leaving a blank but backlit screen?

If the sound dies as well, I'd suspect bad solder joints on the processor chip, a common problem on many LCD TVs, and the set is a writeoff.

If the backlight stays on and only the video dies, I suspect the same thing, and it's a writeoff.

If the backlight goes out and the video stays on the unit, you have hope.. maybe. I have a slew of computer LCD monitors where the backlight dies after a few seconds. Power supply voltages are OK. I suspect changed impedance of the backlight driver transformers or bad tubes in the backlight itself, but haven't had a chance to compare a bad backlight monitor with one that works, as to swapping parts between the two. About all you can do is an impedance check on the transformers, comparing one to the other to see if they change significantly. There's some good information at www.badcaps.net forum here:

http://www.badcaps.net/forum/forumdisplay.php?s=d64decd9c98790870e0061e9f96a20bf&f=31

I personally haven't worked on a Vizio, so my info is pretty generic, but it could be helpful.

[crtcrt76]

Wanman, sorry, they say it only had a 90 day warranty, we got it as a gift, but nothing on the box or tv said it was refurbished (usually the model number sticker ends in -R or -RB for refurbs, and sometimes it's a sticker slapped on top of the original)

Curt! What's up. Backlight comes up for 2 seconds and then dies. The TV works in the background (you can hear the sound, you can switch inputs, turn it off, and turn it on, and it shows the new input for 2 more seconds).

The master inverter board has a blue diag led that comes on, then when the back lights go out, it fades out. Voltages going to each inverter, and all other places are correct and don't fluctuate more than 1v. I don't think you can see anything displayed on the LCD itself if you shine a light on it once the back lights go out, but I may just not be able to notice it.

The master and slave inverter boards are hard to find, but there is a repair kit available for the "black screen of death", which consists of an inverter IC, and 4 transistors. I will swap those out just because it's cheap, and after reading, a common failure point. If it's the bulbs, forget it.

I linked to some modded inverter boards above, they seem to have soldered some alternate paths around the IC and transistors. While I'm waiting for the repair kit to come in, I'll lift the 4 HV transformers off the inverters to see if they match each other.

I found the manual for my TV, it is the VO42L, and not a V042L. The refurbed VO42L that is being sold today locally for some reason is completely different than mine, I assume they redesigned it, and the only original component must be the LCD panel lol.

I can't believe how reliable my CRT's have been compared to all these flat panel monitors and TV's I've used and disposed of since. I think I bought my Marquee in 2000, and other than a few easy fixes, it's rock solid. Hitachi HD RP CRT is awesome still.

[808quebecoise]

[macgyver655]

I am currently not doing board repairs on this model.

[21stReviews]

So are you doing board repairs on other Vizio models such as P702ui?

My friend may need it.

[macgyver655]