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**kingofcoins** · 01-04-2011, 11:31 AM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...Cap repair a no go

The test with the 6 new caps on the mainboard shows NOTHING has changed.
So to repeat the situation and readings...
Set double clicks when plugged in, amber light is on, 165V at main cap, and only 5VDC to mainboard, no other supplys...it then will not kick up by any other means except pressing SW1 and wait about 10 seconds, and it clicks up to white, then main cap is 400VDC, there is then 24 volts and 1.4v to master inverter, and 24v to slave inverter, and there is then 12v, 5v, and 1.4v to mainboard.
No blue diode for ccfl , no backlights or flash at all, no image or sound. Set will not turn off by SW1 but only if plugged pulled , and it will not return to 400vdc level by replugging.
What would you suggest next ?

**kingofcoins** · 01-05-2011, 01:37 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...switch infos

Today I noticed another SW1 on the lower left of mainboard...and it has the reverse action as the control board on/off SW1. This mainboard switch will turn set off but will not kick up the power supply into white...just the opposite of the exterior switch. Does this help at all ?

**PlainBill** · 01-05-2011, 07:04 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...switch infos

Originally posted by kingofcoins View Post

Today I noticed another SW1 on the lower left of mainboard...and it has the reverse action as the control board on/off SW1. This mainboard switch will turn set off but will not kick up the power supply into white...just the opposite of the exterior switch. Does this help at all ?

It really sounds like the main board is flakey. But with a Vizio, it may be working as designed.

PlainBill

**kingofcoins** · 01-06-2011, 10:33 AM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...switch infos

Bill....I agree trouble at this point is on mainboard. I flexed it many spots to no avail.
.>>>>Didn't I see a thread that a set was fixed with a bad SMD voltage regulator on mainboard ....the voltage was low.... was to be 3.3V ...recall the one ??

Originally posted by PlainBill View Post

It really sounds like the main board is flakey. But with a Vizio, it may be working as designed.

PlainBill

**PlainBill** · 01-06-2011, 10:52 AM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...switch infos

Originally posted by kingofcoins View Post

Bill....I agree trouble at this point is on mainboard. I flexed it many spots to no avail.
.>>>>Didn't I see a thread that a set was fixed with a bad SMD voltage regulator on mainboard ....the voltage was low.... was to be 3.3V ...recall the one ??

Not specifically, but this is a common problem. Most 3 terminal regulators have the output voltage incorporated into the part number, so it is practical to measure the output voltage on every regulator and determine if it is correct.

PlainBill

**kingofcoins** · 01-06-2011, 12:16 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

I found that thread about U33:
https://www.badcaps.net/forum/showth...&highlight=U33

Is this where you get some service manuals ? If so see Chapter 9 starting on Pg 90...Where should I start with their trouble shooting chart ?:
.http://elektrotanya.com/vizio_l42hdt.../download.html

**PlainBill** · 01-06-2011, 05:22 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

Originally posted by kingofcoins View Post

I found that thread about U33:
https://www.badcaps.net/forum/showth...&highlight=U33

Is this where you get some service manuals ? If so see Chapter 9 starting on Pg 90...Where should I start with their trouble shooting chart ?:
.http://elektrotanya.com/vizio_l42hdt.../download.html

That's the source. I'll look at it when I get a chance. One of the problems with being fully employed is demands on your time expand to exceed the available time. It doesn't get any better when you're retired.

PlainBill

**kingofcoins** · 01-06-2011, 06:31 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...> Mainboard readings

So that's my problem...not fully employed, and not retired, so the demands on my time expand to exceed the available solutions for any given problem !

Jumping ahead I think we have a faulty component or two on the mainboard. So trying to follow their trouble shooting path I checked these points with the power kicked up, ie white logo and 12v+5v+1.4v into mainboard:
U1 Pins 5,6,7,8 are all... 5V
U5 Pin 2 is.. 1.8V
U4 is not used
U6 Pin 2 is 8.0V.....out of spec !
U8 Pin 2 is 3.3V
U7 Pin 2 is...1.1V.....out of spec !
U9 Pin 2 is...1.5V.....? spec ?
U10 Pin 2 is...2.6V.....out of spec !

J7 is the multi cable connector on top center of board, not sure where the
wires all go, but got these readouts---all seem out of spec:
Pin 1... 0.V
Pin 2... 0.V
Pin 3 ..1.3V
Pin 4 ...1.3V
Pins 10, 11, and 12....0.15V
Pin 14... 0.V

**kingofcoins** · 01-12-2011, 11:32 AM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...mainboard woes

I'm still a bit over my head on this, so when you get a chance...
New point... does the fact I get no backlight action at all mean I need to address
it separately, or is it likely the mainboard trouble keeping them off?

I not sure I took enough info on the last post so here is all the LDO regulator readings
for Vin (1-3) and Vout (1-2) and pin 2 ? (2-3):
U2.... 3.0VDC 1.2V 1.8V
U7.... 3.4 1.1 2.25
U8.... 3.1 1.2 1.85
U9.... 3.3 1.5 1.75
U33... 3.0 1.2 1.8

4 of these are AMC1117 F0646J U9 is a K1117S15 612

**PlainBill** · 01-12-2011, 05:53 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...mainboard woes

Originally posted by kingofcoins View Post

I'm still a bit over my head on this, so when you get a chance...
New point... does the fact I get no backlight action at all mean I need to address
it separately, or is it likely the mainboard trouble keeping them off?

I not sure I took enough info on the last post so here is all the LDO regulator readings
for Vin (1-3) and Vout (1-2) and pin 2 ? (2-3):
U2.... 3.0VDC 1.2V 1.8V
U7.... 3.4 1.1 2.25
U8.... 3.1 1.2 1.85
U9.... 3.3 1.5 1.75
U33... 3.0 1.2 1.8

4 of these are AMC1117 F0646J U9 is a K1117S15 612

The main board controls the backlights.

Hang in there, I got the last of the tile set today. Now to grout it.

PlainBill

**kingofcoins** · 01-12-2011, 10:45 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

Wow not only a super tech but a craftsman as well...nothing 'Plain' about that Bill !

**Dgtech** · 01-13-2011, 06:55 AM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

Hey King , when you get a chance, look at my post (#29) here:
https://www.badcaps.net/forum/showth...974#post129974

This is a quick check to rule out a common problem with these inverter boards. The board design is a little different however the parts are mostly the same. All resistance measurements should be done with the power disconnected.

Please post the readings you get from the eight components (4 per board).

Plainbill gave me flashbacks of my kitchen backsplash. Grouting is ok but cleaning it off when you're done, tedious!

**PlainBill** · 01-13-2011, 07:06 AM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

Originally posted by kingofcoins View Post

Wow not only a super tech but a craftsman as well...nothing 'Plain' about that Bill !

It gets worse. The weather here has started warming up. (Well, if you consider lows in the upper 40's and highs in the lower 70's warm.) That means I can start working outdoors.

My spring cleanup work includes pruning more than a dozen oleanders and about a dozen rose bushes, spraying weeds twice a week, digging a trench 60' long to bury the backwash line for the pool filter, building a work platform so I can repair the shade over the goldfish pond, replacing the shade battens, replacing a piece of siding (that happens to be 8' up in the air), building a support so I can lift 200 lb fountain sections, rebuilding the fountain, cutting down a grapefruit tree that is dying, and spreading crushed rock around a planter.

Now, this wouldn't have been a big deal 40 years ago, but now I can barely work 20 minutes at a time without resting. The good news is I have until the end of May to finish these projects.

PlainBill

**kingofcoins** · 01-13-2011, 12:59 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

Bill you need to take a break from retirement once in awhile....at the computer desk !

At Dgtech's suggestion I ran resistance across the 1-3 legs on those inverter transistors, power off in circuit :
On the Master Inverter all 4 Q14,15,18,19 read source-drain 3.4K-4.1 K ohms
On the Slave Inverter all 4 Q215,216, 218, 219 read only 300-400 ohms
..they are all 8 marked fDG52AD FDD 8447L

The IC mentioned on those boards is a 16 leg 0Z9982GN T02980 4T 0645C1

**PlainBill** · 01-13-2011, 08:00 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

Originally posted by kingofcoins View Post

Bill you need to take a break from retirement once in awhile....at the computer desk !

At Dgtech's suggestion I ran resistance across the 1-3 legs on those inverter transistors, power off in circuit :
On the Master Inverter all 4 Q14,15,18,19 read source-drain 3.4K-4.1 K ohms
On the Slave Inverter all 4 Q215,216, 218, 219 read only 300-400 ohms
..they are all 8 marked fDG52AD FDD 8447L

The IC mentioned on those boards is a 16 leg 0Z9982GN T02980 4T 0645C1

The master / slave inverters are notorious for failures. Recently someone referenced a modification to be done on them to improve reliability.

PlainBill

**Dgtech** · 01-13-2011, 09:28 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

Could you post a picture of the master board and the slave board. Both pictures would include the video driver chip (marked BD9897FS) as well as the 4 components that you measured.

These inverters also have one fuse each. Did you check these yet?

**kingofcoins** · 01-13-2011, 10:57 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

DG...Thanks....the fuses were checked early on, both OK ~0. Sorry I mistook the video driver chip as being the only one on the slave board, but as you mentioned the chip is found then only on the master and mine is a BD9897FV.
See my post #! here for the pics , if you need better advise. The 4 FDD 8447L mosfets measured should also show.

**smason** · 01-14-2011, 08:58 AM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

Originally posted by PlainBill View Post

It gets worse. The weather here has started warming up. (Well, if you consider lows in the upper 40's and highs in the lower 70's warm.) That means I can start working outdoors.

I consider that warm. It's been stuck at -19 to -25C here for a week.
My working outdoors consists of shovelling snow, scraping ice off the driveway, and trying to scoop frozen doggie doo.

**PlainBill** · 01-14-2011, 08:31 PM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...

Originally posted by smason View Post

I consider that warm. It's been stuck at -19 to -25C here for a week.
My working outdoors consists of shovelling snow, scraping ice off the driveway, and trying to scoop frozen doggie doo.

I feel for you - a little. I grew up in Minnesota and lived there for more than 30 years. We got your cold weather after you got tired of it. Nothing quite like the thrill of sitting on a cold car seat at 20 below.

PlainBill

**kingofcoins** · 01-16-2011, 11:01 AM

Re: Vizio VW42LFHDTV10...Brother Mikes TV...fix it for LXV ?

While you're talking weather, I'm frozen here in Steeler country, but its OUR time of year...and I'd sure like to get a handle on this set for Brother Mike to watch the nation romp on Feb 6th ....any ideas for me yet ?

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