Westinghouse W1603 TV Repair

[SeanB]

That then exonerates all the digital side, leaving the tuner alone. Is the system set correctly, best is to change to another system, then scan again, then change back to the country system you are in and rescan. That way, if it was eeprom data errors it will be written correctly, and if not then the tuner itself has died, probably from a high voltage zap on the antenna input.

Easy enough to change the tuner with a donor from another set, but if it has died you probably are better off getting an external cable box or satellite receiver and using HDMI to connect.

[KhronX]

In that case, it sounds to me like it works as well as you can hope. 

When you've got nothing connected to an input, would you expect it to display anything else than "hey, i'm getting no signal at the input you've selected" ? 

Or is the tuner section still not working?

[Fisher77]

Well when hitting the chanel up or down buttons, it does not change the channel, but without an antenna or cable input, it probably wont change channels. The big problem is the only way to get it to turn on is by jumping the 3.3v stby to the ps_on at the power supply.

[KhronX]

Silly question perhaps, but is the connector to the button-board, and the remote-sensor respectively, plugged in?

And/or is there a supply voltage present on any of the pins of those connectors?

Well when hitting the chanel up or down buttons, it does not change the channel, but without an antenna or cable input, it probably wont change channels. The big problem is the only way to get it to turn on is by jumping the 3.3v stby to the ps_on at the power supply.

[Fisher77]

Silly question perhaps, but is the connector to the button-board, and the remote-sensor respectively, plugged in?

And/or is there a supply voltage present on any of the pins of those connectors?

Yes both plugged in, I checked, and both do have voltage. Input button, menu, and volume buttons on the side of the tv all work. Unfortunately, I do not have the remote in my possesion to test it.

I also removed the jumper. Even though the power supply is providing the 3.3v stby, the stby led on the front of the tv is not lit up.

[pyroesp]

Now that I got this "bumped" & going again...

Well done dude, go ahead pat yourself on the back.

@Fisher77: from the silkscreen on this image : https://i.imgsafe.org/701d1871f9.jpg , you don't seem to have a 5VDC output. Unless the 5VDC is regulated on the CPU board ... ?

@Aquamon: This is the 3rd non working TV. Not the same as the one in the first post.

[Fisher77]

12V from the ps gets regulated down to 5 on the main board, or at least thats what it looks like in the manual.

Service manual is here. Mine is the one in the red box in the pic:

http://elektrotanya.com/?q=showresult&what=Sony%20KDL-32L5000&kategoria=&kat2=all

[Fisher77]

It has the 5 volts on the main board

[KhronX]

I kinda figured as much. I'm willing to bet big bucks the tv wouldn't start and be able to display a DVD playing back, without the 5v rail being present 

It has the 5 volts on the main board

[Fisher77]

I kinda figured as much. I'm willing to bet big bucks the tv wouldn't start and be able to display a DVD playing back, without the 5v rail being present 

Right, and I would not bet against you on that one.

I thought of something while I was sitting here this morning. I was testing that with the jumper in . So the power supply was supplying the main board with the 12V. If I pull the jumper out, the power supply turns off, 12V is gone because the power supply is off, and the 3.3V stby drops to .4V with the main board cable connected to the power supply.

Unplug the cable from the power supply to the main board and the stby remains at .4V.

Unplug the power supply from the mains for a few minutes, plug it back into mains, and the stby is back to 3.3V. Reconnect the cable from the power supply to the main board, the relay on the power supply clicks on, then clicks off, and then the stby drops back down to .4V, and remains there until the power supply is disconnected from mains again for a few minutes.

I hope the way I explained that is understandable.

What the hell is going on here. Is it a power supply issue, a main board issue, or a little of both?

[KhronX]

Could something be overloading / dragging down the 3.3v stand-by rail?

Here's something (else) to try - if you keep the power supply plugged in, but the mainboard disconnected, does that stand-by rail stay at 3.3v, even after the time interval it would drop out if the mainboard was hooked up?

[pyroesp]

Here's something (else) to try - if you keep the power supply plugged in, but the mainboard disconnected, does that stand-by rail stay at 3.3v, even after the time interval it would drop out if the mainboard was hooked up?

From previous posts it looked like the 3.3V was stable, but it looks like once the 3.3V has been loaded down to 0.4V it can't get back up to 3.3V as stated here:

Unplug the cable from the power supply to the main board and the stby remains at .4V.

@Fisher77: You could try to load the 3.3V down with a small value resistor (maybe a pot to have some control over the current drawn) and check whether the 3.3V is stable or not.
If what Aquamon stated about the 5V is true, then the 3.3V going to the Power On is not controlled by the CPU. The CPU needs 5V, and 5V is only regulated from the 12V going out of the power supply board.
Whatever is linking the standby 3.3V supply to the power on might be shorted to ground or loading the 3.3V rail down on the main board.

[KhronX]

Oh grow up!... 

[KhronX]

Funny you should say that - if anyone "feels" like they're trolling, it's actually you 

[pyroesp]

Why are you so butthurt ? Is it because someone did not do what you asked ?

One commenter obviously haven't even bothered to do that and only goes to show his true intentions...

I can't see a download link on the website you gave, all it shows is "...processing...". I've had the webpage open for awhile and never got a link.

As far as my intentions are, I'm trying to help.

It's true I might not have your experience, but at least I have the humility to not call (or insinuate) I'm an expert and ordering people what to do instead of explaining why they should do something.

Is it not so that you don't have 5V unless the 12V is present on the main board ?
The 12VDC is only generated when OP jumped the 3.3V to the P_ON pin. So this, and the last post from OP, leads me to believe there's something wrong with the 3.3V.
Is that not the next step to do? Try and solve the 3.3V rail ?
I don't see the logic in jumping straight to checking the 5V or EEPROM(s).


This is a forum, people have opinions and ideas that might differ from yours. If you can't live with that, then leave. Instead, you behave like a kid who couldn't get what he wanted.

[pyroesp]

I managed to get the pdf through my phone. Why it wouldn't give me a link on my laptop I don't know.

If this is the TV that got zapped by lightening, more than likely the tuner is shot, which uses 5V.

All 3 tv's have been damaged by a lightning strike.


From the schematic the power on goes through transistor Q210. There's a test point TP001 you might want to measure.
If it's high then the transistor should put the 3.3V (minus the Vce) on the power on.

[pyroesp]

True, everyone values their time how they want.
I don't know if OP has better things to do, but he said he wanted to keep the cost to a minimum, so I don't see the harm in checking a few more things before giving up and buying a new main board.

Does the tuner have a part number on it ? If it's fried, how much would a new tuner cost ? (Haven't checked this in the manual yet, will check that now)

[Fisher77]

Here's something (else) to try - if you keep the power supply plugged in, but the mainboard disconnected, does that stand-by rail stay at 3.3v, even after the time interval it would drop out if the mainboard was hooked up?

Tried this and the stby stayed at 3.3V stayed for over an hour. That is as far as I got today before being drug away for the glorious Christmas shopping.

[Fisher77]

True, everyone values their time how they want.
I don't know if OP has better things to do, but he said he wanted to keep the cost to a minimum, so I don't see the harm in checking a few more things before giving up and buying a new main board.

Does the tuner have a part number on it ? If it's fried, how much would a new tuner cost ? (Haven't checked this in the manual yet, will check that now)

Off of work for the next 2 weeks. I don't have anything better to do. If it comes to ordering a board I will, but why not try to repair the thing, and learn something in the process.

Question: Is the tuner going to prevent the TV from turning on?

[KhronX]

I'm sorry for asking, but what exactly IS your problem?

Is anybody holding a gun to your head and keeping you "hostage" on these "dead" forums? 

If this is "taking too long", consuming mental energy, and your time is oh-so-precious... What exactly are you doing here again? 

It's Fisher77's TV, it's his time, it's his energy, he's free to do whatever he pleases. And i'm pretty sure he doesn't owe you repairing this in whatever arbitrary time-frame you decided 

If something doesn't please you here, you're free to leave and find other groups of people who are more worthy of your time and energy - we obviously are not, and don't even come close to your standards

My last comment was really because for myself (and most likely other readers), reading a schematic and waiting in a "dead" forum - waiting on what progress has been made, does consume mental energy.

[...]

I hope you "get lucky", but it is taking too long.

[Fisher77]

As you did not update, I would suggest replacing the board at this point...

 
I did not realize that I had a set schedule that I needed to follow there BOSS. Pardon me for not updating this thread every five minutes for you. You know at this particular moment this is not all that I have to do, especially with Christmas the day after tomorrow. After the Christmas holiday, I will have plenty of time to spend on this.

This is a "Sony", is no joke.
This was never revealed earlier.
The schematic is revealing enough as to "propriety" stuff, "DESTROY".

Maybe if you would take the time to read all of the posts you would see that the brand, and model number were revealed in post #15 of this thread.

I have never ordered any board in this lifetime.
I just threw away a LCD TV as a matter of fact.
Why?  Because the fellow died and I couldn't be bothered to order similar things mentioned in another post (regarding Inverter Section).

Good for you, glad you never ordered a board. Neither have I, and this is not the first tv I have fixed, yet this is the first one that there has been a issue on the main board, so I simply posted here for help. So far, the only help you have offered me is to just throw the damn thing away, or chunk parts at it without trying to diagnose the problem. Furthermore it must be nice to have a pocket book thick enough to just throw a TV in the can, and run out and buy a new one. You know not everyone is in that postition.

waiting on what progress has been made, does consume mental energy.
I hope you "get lucky", but it is taking too long.

There again I did not realize I had to stick to your schedule. As mentioned by KhronX I am not holding you here. As far as your mental energy is concerned, I recommend you make an appointment with your psychologist, take some meds, and get over it.  It is my time, and if I feel like spending a month on it I will. If you feel it is taking tooooo looooong, then feel free to move it on down the line. I did not ask you to post on my thread. You might also want to reconsider if you want to be part of a forum or not. I can assure you that the behavior you have provided  us here on this thread is not going to get you any brownie points on any forum that I know of.

If you do decide to buy a board, make sure the screen is good, at least.

Make sure the screen is good.
Do you really think I would be spending this much time trying to fix the damn thing if the screen was not good. Would you like to see a picture as proof??? This is further proof that you have not bothered to read all of the posts. If you would have read them, you would see that I had a DVD player, playing a movie, connected to the TV in post 28.


I agree with KhronX. You are free to go. Go find yourself another group of know it alls to hang out with. Doesn't seem to be enough professionals around here for you. Before you join another forum though, I suggest you make sure they want to stick to your time constraints there , or your mental energy will be totally drained.

[pyroesp]

Question: Is the tuner going to prevent the TV from turning on?

Well you already know the TV works by jumping the 3V3 to the power on.
I wouldn't think the tuner, which is your RF receiver for your analog signal/antena, could prevent the TV from working.

From the block diagram on p.26 of the manual, you can see the tuner in the upper left corner (RF in).
None of the arrows going out of the tuner go to something important like the regulator ICs, only to some analog or digital signal processing block.

[Fisher77]

Thats what I see to. I am still trying to fathom how a tuner is going to keep a tv from powering on.

 I was reading the previous post you made about using a low value resistor to load the 3.3V. What value do you think I should use?

[Monkeh]

the 3.3V stby drops to .4V with the main board cable connected to the power supply.

Something connected to the 3.3VSB rail is either drawing excessive current, or the power supply is unable to handle the normal current it does want. The main 3.3V rail is generated by a 5A(!) capable LDO from the +5V rail, which itself is generated from the +12V rail by a buck converter. Clearly the LDO is stiff enough to handle whatever demand is placed upon it.

Find L215 (should be near IC204, the LDO) and measure the voltage across it. It's not exactly a current shunt, but it may serve the purpose. It's rated for 2A at best, so if you see upwards of 20mV across it, that's a pretty clear indicator of a fault. If it's a very low value I'd suspect a weakness in the power supply.

As far as loading the standby rail goes, somewhere in the 20-50ohm region should be enough to determine if the supply is weak - it should have no problem with supplying such a load with no notable droop. Be warned typical small resistors will get quite hot, quite fast, but they'll do the job.

And for the tuner, it does have a few connections running around the place - half of which are AC coupled and the other half have resistors inline which should prevent pulling the standby rail down that hard. Any damage via that route is in the main IC.

[pyroesp]

Something connected to the 3.3VSB rail is either drawing excessive current, or the power supply is unable to handle the normal current it does want. The main 3.3V rail is generated by a 5A(!) capable LDO from the +5V rail, which itself is generated from the +12V rail by a buck converter. Clearly the LDO is stiff enough to handle whatever demand is placed upon it.

Find L215 (should be near IC204, the LDO) and measure the voltage across it. It's not exactly a current shunt, but it may serve the purpose. It's rated for 2A at best, so if you see upwards of 20mV across it, that's a pretty clear indicator of a fault. If it's a very low value I'd suspect a weakness in the power supply.

The main 3.3V is only generated after the 3V3SB is sent back on the Power ON line and the reg 12VDC is sent from the power supply board to the main board.
I'd think it's something on the standby voltage circuit that's pulling the voltage down, like maybe C209 or C210 ?