RCA l42wd22yx6 no video or sound

[Dgtech]

Re: RCA l42wd22yx6 no video or sound

HOTHEAD, Please check my post on the link below for how to check these inverter boards. This may be part of your problem.

https://www.badcaps.net/forum/showth...974#post129974

[HotHead]

Re: RCA l42wd22yx6 no video or sound

Hey all back again with a new multimeter Ce digital multimeter ET-1039.

Tested my powersupply and readings seem better this time around.
With everything still plugged:
My +5v on 3,4 reads 4.9v
+24v on7,8 reads 24.4v
+12v on 3 reads 11.7v
And the last one +18v on 1(which is not connected to anything) reads 12v
thats the one that baffles me but figure its not important since its not connected.

When i try to measure the powersupply with no load on it, ie nothing connected after, i get no reading at all from the 9 pin connection(24v,12v,18v) but still read 4.9v on the +5v 4 pin connector.
Is this normal?

Thx dgtech for the insight on the inverters. I will read more thouroughly as soon as i get the tv back open and have access again.
Even though our tv sets are different your inverter ressembles mine very closely. Should reading be similar also?

[retiredcaps]

Re: RCA l42wd22yx6 no video or sound

Speaking of the inverter boards, did you test the fuses to see if they are open? A good fuse should measure less than 1.0 ohms.

[PlainBill]

Re: RCA l42wd22yx6 no video or sound

my digital multimeter starts to display random results once the 9v battery is done (around 8V or below)
was quite a bit puzzled when i measured AA batteries and it showed 4 Volts lolol

even more odd that it doesn't show the low battery icon till the battery is all the way down to 7.0V (so you'll be measuring bullshit for a while till it actually tells you the battery's dead..)

just saying.. your multimeter might be messed up like that too..

Wow, this really makes me feel old.

Guys, that's a VOM. They will measure voltage and current perfectly with a dead battery. It probably has a single AA penlight battery used only for measuring resistance. Notice Zero ohms is on the right end of the scale.

The biggest cause of errors on those is the eyeball reading the meter. It is very easy to read the wrong scale.

PlainBill

[PlainBill]

Re: RCA l42wd22yx6 no video or sound

Hey all back again with a new multimeter Ce digital multimeter ET-1039.

Tested my powersupply and readings seem better this time around.
With everything still plugged:
My +5v on 3,4 reads 4.9v
+24v on7,8 reads 24.4v
+12v on 3 reads 11.7v
And the last one +18v on 1(which is not connected to anything) reads 12v
thats the one that baffles me but figure its not important since its not connected.

When i try to measure the powersupply with no load on it, ie nothing connected after, i get no reading at all from the 9 pin connection(24v,12v,18v) but still read 4.9v on the +5v 4 pin connector.
Is this normal?

Thx dgtech for the insight on the inverters. I will read more thouroughly as soon as i get the tv back open and have access again.
Even though our tv sets are different your inverter ressembles mine very closely. Should reading be similar also?

Yes, that's normal. You'll notice that one of the pins is labeled On/Off. That is a dual power supply. The 5V standby output is live whenever it's getting AC power. This powers the standby processor on the main board. When the power button is pressed the standby processor switches the main supply on by raising the On/ Off pin to something above 3 Volts.

PlainBill

[HotHead]

Re: RCA l42wd22yx6 no video or sound

Finished testing out the 4 components on both inverters and they all read 8.5 ohm. I'm still looking for a fuse. Not sure what it looks like. I beleive it to be to the right(on the master) of the capacitors between both of them. If it is, there is only one on the master and none on the slave.
It looks like a see thru box with a strip on metal inside. Wow these things are tiny. If this is a fuse i get a reading of infinity.


Since i also have no sound is there any way i can test the main-video board?
Any tutorials would be helpful.

[retiredcaps]

Re: RCA l42wd22yx6 no video or sound

If this is a fuse i get a reading of infinity.

From your picture, it looks like they are white on the inverter boards. The PCB will usually denote "F" for fuse. For example, F100 is a fuse.

If it reads 0L ohms, you have a bad fuse.

[smason]

Re: RCA l42wd22yx6 no video or sound

Wow, this really makes me feel old.

Guys, that's a VOM. They will measure voltage and current perfectly with a dead battery.
PlainBill

LOL. We could tell them about VTVMs but they wouldn't believe us...

[HotHead]

Re: RCA l42wd22yx6 no video or sound

Well i have one blown fuse on the master board and the slave is reading .9 ohms on setting 200. The fuse is f10a. Is there a specific name for these little fuses?
Fuses have a life expectancy, should i replace both of them while i am in it?
Before i run back to the store tomorrow is there something else i can check that would be obvious?
thx

[retiredcaps]

Re: RCA l42wd22yx6 no video or sound

The fuse is f10a.

The value of the fuse is usually written on the PCB with its amps and volts rating. You need to measure the width and length of the fuse. You can then narrow it down on digikey.com after you find the above info.

[HotHead]

Re: RCA l42wd22yx6 no video or sound

Ok, so back for another evenning.
I have been searching for the same type of fuse from a local dealer but haven't tracked it down yet.
One tech suggested a fuse( i forget the name) that looks like a resistor at the same amp. That is what i have installed.
Another tech at a different store suggested the old glass tube with filament inside type. Curious if those would even work? The wire gage was quite large on the connections.
Anyway, long story short after replacing 4 caps and one fuse(i would of replaced both but i kinda butchered the pcb when i removed the suface fuse, so decided not to try the other one, Yet) plugged everything back in and booted it up.

It works! :-)
Here are some pics of what i did to the master inverter. Bear in mind i haven't soldered or even though of cicuits for over 15 years. Sooo happy it works! I had to cut the metal sheild to accomadate the new caps which are quite larger than the originals. The fuse fits no probs even though its twice as high.

Thanks for the great help everybody that contributed to this post and the ones i have read. Hope some info in here can help others.

Thx for the patience with my newbish questions.

For the VTVM comment. Are you talking about a tube based meter? I have a few old tube based radios. One is working!

Great site.

p.s. should i be worried about why it failed or is it just the cheap caps that blew things?

[retiredcaps]

Re: RCA l42wd22yx6 no video or sound

I had to cut the metal sheild to accomadate the new caps which are quite larger than the originals.

Personally, I would have re-ordered the correct size to avoid cutting into the shield.

But the important news is that it works. Good job.

[marksdaleblvd]

Re: RCA l42wd22yx6 no video or sound

Ok, so back for another evenning.
I have been searching for the same type of fuse from a local dealer but haven't tracked it down yet.
One tech suggested a fuse( i forget the name) that looks like a resistor at the same amp. That is what i have installed.
Another tech at a different store suggested the old glass tube with filament inside type. Curious if those would even work? The wire gage was quite large on the connections.
Anyway, long story short after replacing 4 caps and one fuse(i would of replaced both but i kinda butchered the pcb when i removed the suface fuse, so decided not to try the other one, Yet) plugged everything back in and booted it up.

It works! :-)
Here are some pics of what i did to the master inverter. Bear in mind i haven't soldered or even though of cicuits for over 15 years. Sooo happy it works! I had to cut the metal sheild to accomadate the new caps which are quite larger than the originals. The fuse fits no probs even though its twice as high.

Thanks for the great help everybody that contributed to this post and the ones i have read. Hope some info in here can help others.

Thx for the patience with my newbish questions.

For the VTVM comment. Are you talking about a tube based meter? I have a few old tube based radios. One is working!

Great site.

p.s. should i be worried about why it failed or is it just the cheap caps that blew things?

Hey, do you have the part numbers for those caps on the master/slave inverter boards? I have the same problem you had. Also, where did you purchase the caps from?

[HotHead]

Re: RCA l42wd22yx6 no video or sound

There is no part num on the caps or fuse just the value.
35v
470uf
105
and the fuse was a 10 amp.

Neither of the 2 stores had the surface mounting fuse i was looking for.
They are both situated in montreal. Very easy to get to if you live close.

One is near the Kraft company

ABRA Electronics Corp
5580 Cote de Liesse
Montreal, QC
H4P 1A9
and is the better of the two hands down.
The other is in the west island part of montreal. forget the name.

[microvibe]

Re: RCA l42wd22yx6 no video or sound

i have question about this tv, my invertor boards have problems as well, the master needed 2 new caps everything else is fine on master, the slave had blown fuse and 2 of the fairchild mosfets are burnt. if i leave slave unpluged and turn tv on the master lights up blue for few seconds then off again but i have no picture even with flashlight, shouldnt i get a picture even if the backlight inverters arent working?

[microvibe]

Re: RCA l42wd22yx6 no video or sound

welli replaced the the fairchild fets with 4 from lc320em2f power board weren't fairchild but data sheets on both were similar.TV works again and very nice picture.happyending for me.

this site has helped me repair 3 tv's just from reading the posts, thanks for all the info