Sony KV-8AD11 ac/dc TV power on issues.

[Electronics Challenged]

The TV has been working fine for many years and recently won't power on. The a/c power cord is fine, as I've tried it on another old Sony TV and it works fine. As an attempt to eliminate different parts, I tried to power the TV in my car with the d/c power cord and it powered up immediately.

This made me think the power supply board was bad, so I bought a brand-new one (6A00349-2). After installing it the results are the same...no power with a/c cord and works fine with d/c cord.

Is the next part to replace the main board? I have no knowledge, or tools, to test any internal electronic parts, hence the user name. Lol I do have knowledge of working on computers, so not afraid to dive in and replace the main board, it that might be the next thing to do.

Short of taking it to a repair shop, anyone have any thoughts on what else may be the culprit?

Thanks,
John

 

[Bluejets]

Connector D601 appears to be a 4 pin connector and the markings on it suggest a remote bridge rectifier. ( 2 AC markings and 2 DC, positive and negative)

Has this been checked.

Difficult for you to do anything unless you have even a basic understanding and a multimeter.

 

[Electronics Challenged]

Connector D601 appears to be a 4 pin connector and the markings on it suggest a remote bridge rectifier. ( 2 AC markings and 2 DC, positive and negative)

Has this been checked.

Difficult for you to do anything unless you have even a basic understanding and a multimeter.

I found the D601 connector, but it came attached to the new power supply board. I have a multimeter, but I have no idea what settings to use to test this connector.

 

[Bluejets]

It's not to test the connector, rather, to see and check what is hooked to the other end of it.

Would help to supply a few photos of what you can see there, we are flying blind.

Have a feeling this is going nowhere and you need somone with some electronics experience.

Not only that but you are getting into mains voltage areas which can be lethal.

 

[Electronics Challenged]

Trying to upload pictures, but keep getting an error. It tells me there is a problem uploading my .jpg files, but it doesn't tell me what the problem is??

 

[bertus]

Hello,

The size is likely to big.
Rescale the picturs so that they are about 300 kB.

Bertus

 

[Electronics Challenged]

Here are picture of the old, defective power board I replaced with a new one.

 

[Electronics Challenged]

 

[Electronics Challenged]

Here is the new board...before and after, installation.

 

[Bluejets]

This is like getting blood out of a stone............. again I'll ask.....where does the wiring which plugs in to D601 go...??
Can you show a photo of that.
I'm guessing it it a remote bridge rectifier unit.
Without that, nothing works.

 

[Electronics Challenged]

Sorry I am taxing your patience, but as I said at the beginning of this post...I do NOT have a lot electronics experience, so joined this website in an attempt to learn from you guys that have much more experience than I do, in an attempt to solve my problem. I have 45+ years of programming experience on mainframe computers, and would expect your questions on a website for "legacy programming" to be less than "smart" or "know it all", but I can assure you, I would make every attempt to help you get maximum blood out of YOUR stone!.

I will again try to answer your question(s). I previous pictures do in fact show the D601 connector from both sides of the board. To me, it is nothing more than a black, plastic, rectangular cube, soldered to the board, with no way of "plugging" any wires into it. As I have said, there are 4 wires that DO plug into the board, but they do not plug into the D601 connector.

In the last picture above, what is in the the D601 connector is located directly below the "125V" inscription at the top of the board. I'm sorry, but I do not know the technical description of this black, rectangular "thing". The preceding two pictures of the underside of the board, clearly shows the D601 at the center, top of the board.

I will gladly try to provide you, or anyone else who responds, with any additional information you might need, in your attempt to help me with my problem, but as I have said...my depth of knowledge of electronics is limited...but I'm trying to learn.

 

[Bluejets]

I cannot see what you can see, therefore relying on your photos which are not clear in the area of interest.
Therefore, from your current description can only gather the bridge rectifier IS the "black plastic connector"

Assuming you have continuity to the mains power, (connector CN603 I think...hard to see numbers as out of focus)
Then check to see if you are geting continuity of mains power to the 2 sine wave symbol terminals on the bridge rectifier. (mains supply requires great care)
It is possible it requires a relay to energise to get power here.
If ok there, test the bridge rectifier (DC......again high potential if energised)
Test proceedure with a multimeter on diode range for powered down bridge rectifier units on Google.

Test for any relays in the above circuit for continuity and correct coil resistance.

Once again.....note the warnings about playing with mains powered equipment........It is NOT the place to start learning.
You have been warned.

 

[73's de Edd]

Greetings Kind Sire . . . .

OH TAY ! . . . . .its a SUNNY !

Of post #7's . . . . . Fottie-graf #1 . . . . . I am seeing meselfs, one decrepid OLD powers supply, particularly in later Fottie # 5's
foils of the DC-DC converters main power area.
ALSO . . . it's being resplendidly compleat, with its 3 POOCHED up/out DC filter E-caps in the output DC power section of the supply, located near reference test point TP601 gnd .

So, with this being the OLD supply, go on over to the corner from TP601 and find one each, white--- pinch and lift--- to release type connector, designated as CN606 . . .or . . . CN605 ? . . . with a heavier preponderance of it being towards the CN606.
Well, that is a male 3 pin connector that is soldered to the DC-DC Converter power module .
Whereas, the STILL connected top female connector, with its clipped off, heavy gauge ORANGE and ? BROWN? PURPLE ? other color of wire,
( it having no connection being made to the center pin) . . . . . . it belongs to the TV DC power wiring harness.

Now on your last photos of the new module, I see bare pins with no solder residue on them ( as if bodging a makesift connection) where female CN 606 would normally plug in.
How did you connect from that connection into the Tee-Wee, as that is being the equivalent of your battery supply to the TV . . . . when using in AC power operation mode?.

Thaaaaaaaaaaaaaassit . . . . .
NOPE ! Looks like they come that way as another new one on E-bay looks the same.
The little CN 604 4 pin connector has its closest to the edge pin of the board as ground (the BIG heavy buss) and the next pin is blank and the next pin is + power and the last pin drives the relay so see if DC power is at the first and third pins .

73's de Edd. . . . . .



.

 

[Technomaniac]

Make yourself up a lampholder with a couple of insulated wires.connected to it. Strip the other end of the wires about 3mm. Fit a 220v 60W incandescent lamp. (That's an old-fashioned one with a filament, NOT an LED , compact fluoro or Quartz Halogen). Turn the set off and unplug from the mains.Use this lamp to discharge the voltage which may be held in C604 before you stick your fingers in touching ANYTHING. ASSUME that there will be more than 300v in that capacitor, EVEN with the set turned off.. When you have it safely discharged, prop the board up in a safe position, insulated from everything while you try the set. First thing is to see if there is any DC voltage coming out of connector CN605. If you have no multimeter, use your new test lamp. But keep fingers off any metal bits and off ANYTHING except your insulated table. If you have output from the power supply,OK. But you probably have to operate the GO button on the front, and/or on the remote control. If you need to touch anything, power off, unplug the mains plug and discharge that C604 every time first. There may also be voltage charged up in capacitors C613 and C614.. There may be as much as 150 volts here. So discharge these two as well, every time.
Do you have any sign of life? You have try pushing buttons to turn it on, a POWER button, CHANNEL UP, CHANNEL DOWN, etc, and if there is a mechanical pushbutton switch, that will have to be latched in the IN position while you are trying all of the above.
If there is no sign of life, unplug, discharge, unplug CN605 which appears to be the output of the power board. Next, connect your test lamp across those pins on the power supply board, leaving the connector aside. Try the starting procedure to see if you now have output. If not, the power supply is probably faulty. If you DO have the lamp lit, there must be something on the main board of the set, drawing too much current. But let's see how we are doing up to this point before we take the next step.

 

[Bluejets]

It's a brand new board so doubtful it is faulty(possible but doubtful) which is why I suggested looking for any external control mechanism.

 

[Technomaniac]

That CN604 seems to be in the Degaussing circuit. I couldn't see any control inputs. It looks like the power supply runs continuously and all of the on/off is done in the micro controlling the line output stage maybe.

 

[73's de Edd]

I say there, now . . .is the party of the first party . . .twice removed . . . . ever going to come back and give any updates or fill ins ?

 

[Technomaniac]

Little woman might have nagged it to the tip.

 

[Harald Kapp]

where does the wiring which plugs in to D601 go...??

Which plug?
Following the inscriptions:




D601 is soldered right into the PCB:

 

[Technomaniac]

The bridge rectifier D601 is already THERE. No need to worry about it. It is NOT a connector, it is a COMPONENT and is correctly fitted.