Vizio VW42LFHDTV10...Brother Mikes TV...

[PlainBill]

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

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

PlainBill

[kingofcoins]

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]

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

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

[Dgtech]

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!

[kingofcoins]

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

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

[PlainBill]

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

The main board controls the backlights.

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

PlainBill

[kingofcoins]

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

[kingofcoins]

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

[PlainBill]

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

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]

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]

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 ??

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]

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 ??

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

PlainBill

[PlainBill]

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 ?

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

PlainBill

[kingofcoins]

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 ?

[kingofcoins]

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]

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

I took out the 6 Taicon caps from the mainboard, and all 6 had actual ESR's
about 4 to 5 times what I would call OK to leave, and up to 16 times higher than the Panasonic FM's I installed.
Interesting the out of circuit ESR's were in all cases about 10-20% lower than the in circuit nos I read..eg, those parallel 0.76 in circuit caps both read about 0.65 when pulled.
Now that they're off I see they where mostly Taicon series VT with the two 'poor' ones series VZ.
Results of fix...see next post...>

https://www.badcaps.net/forum/showthread.php?t=388

From some comments I have seen, you are only half right. Seriously, you should trust the readings of your ESR meter over what some guy in Phoenix says. A cap that gives a bad reading is bad. A cap that reads a good ESR is almost certainly good, and is not the cause of a problem you are seeing. If it is a garbage brand, it may fail soon, but it hasn't yet.

PlainBill

[PlainBill]

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

So any opinions on all these Taicons on my board ? Do they have good and bad series ?

https://www.badcaps.net/forum/showthread.php?t=388

From some comments I have seen, you are only half right. Seriously, you should trust the readings of your ESR meter over what some guy in Phoenix says. A cap that gives a bad reading is bad. A cap that reads a good ESR is almost certainly good, and is not the cause of a problem you are seeing. If it is a garbage brand, it may fail soon, but it hasn't yet.

PlainBill

[kingofcoins]

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

So any opinions on all these Taicons on my board ? Do they have good and bad series ?

C0647 denotes year 2006 and week 47. This is when the caps were made.

[kingofcoins]

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

Bill....what I meant was an acceptably low ESR reading for a used cap regardless of series or manufacturer...as a guide I use in LCD circuits....

1) Bob Parker's K7214 table...I want my caps at less than half of his values:


2) Kakopa's design...I like the high quality or better columns:
http://kakopa.com/ESR_meter/

You are going to have to do that yourself. Start by looking for a datasheet based on the manufacturer and series, then looking up the ESR for the capacity and voltage. Remember this is a 'better than' value. A capacitor with an ESR rating of .05 ohms might read .02.

PlainBill

[retiredcaps]

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

On the Mainboard they are all 70 TAICON's, of several series like C0647

C0647 denotes year 2006 and week 47. This is when the caps were made.