Sony KP-46WT500 Flashes Blue, 8 blinks.


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Sony KP-46WT500 Flashes Blue, 8 blinks.

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randomdes
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May 13, 2010, 9:30 PM

Post #1 of 25 (4110 views)
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Sony KP-46WT500 Flashes Blue, 8 blinks.	Can't Post

Hi,

I have just picked up my second sony HD projection tv, and am trying to fix it. Ron M. helped me fix my last one, so I'm hoping this forum can be of use again.

When I acquired it, it was doing this:

http://www.youtube.com/watch?v=OZTLWCsPYZU

Which to my uneducated eye looked like a screen bias adjustment issue. So I got it home, turned down the screen bias, and the TV flashes less, and doesn't shut down, but it started smelling nasty. On further inspection, R7324 was starting to burn up.

I then tried pulling the blue driver board off the tube, and running the set that way. No excessive current draw, but I hear arcing. At this point i quickly shut the set down, as my last projection damaged a tube by arcing.

The arcing happens after a similar amount of time, and in a similar pattern to the blue flashes when the blue board is attached.

I'm not sure what to troubleshoot next, so I thought I'd get some guidance from here, since probing about test points isn't really an option unless I have a good plan.

Thanks in advance,
Ian

Ron.M
Veteran

May 14, 2010, 1:08 AM

Post #2 of 25 (4102 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

randomdes;.....

Our "buddy" "EL_88" did NOT say a thing about any arcing....
Also it appears he took my advice & got a local TV repairman to look at the set....
The repairs he/you need may be the reason the set was put on Craigslist...... Unsure

.....

Here we go....
On the outside going up the side of the Blue CRT is a heavy Red wire....
That wire has about 30,000 volts on it when the TV is on....
And it holds a LOT of it when the set is OFF....
Follow that wire to a splitter "box" that looks like the one in the pix below....

With the TV OFF....
You'll see an extra empty spot on the far right side....
IF you can EASILY remove the cover on that spot , do it...
Then stick a GROUNDED wire down into the empty spot to discharge any voltage there....
Re-cover the spot...
IF you could NOT remove the cover , CAREFULLY remove the Blue CRT wire as shown , (Push down on the wire & turn it 90* counter clockwise) using care NOT to touch the end of the red wire & then GROUND the end of that wire to discharge the voltage....
Swing the wire out of the way & clear of ALL other wires , boards , etc...
Next hook up ALL the other wires & CRT module/panel/board....
Turn on the TV & watch R7324 for overheating.....
Should be none....
Check & see if the Red & Green comes on....
If not , turn up the G2 volts for green &/or red just a bit....
Check if you get video & what it looks like....

Post with what you see & hear , what you don't see or hear....

Thanks....

Later....Ron.M.... Cool

....
Veteran & Retired TV technician

(This post was edited by Ron.M on May 14, 2010, 1:13 AM)

randomdes
New User

May 14, 2010, 2:03 AM

Post #3 of 25 (4096 views)
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Re: [Ron.M] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

With the blue HV line removed and everything else hooked back up, I see a yellowy signal that flickers (yellow expected, flicker not expected.)

More smoke came out of the resistor. At this rate I may have to replace it soon :). Luckily it still resists.

No light codes noticed. No arcing heard. But the image was very flickery. dramatically changing in brightness, but never disappearing. Besides that it looked fine.

(This post was edited by randomdes on May 14, 2010, 4:10 AM)

Ron.M
Veteran

May 14, 2010, 7:41 PM

Post #4 of 25 (4077 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

randomdes;.....

The "flickering" may be due to the settings of the "G2's"....
Not to worry about right now.......
R7324 is a 1K 1/2 watt resistor that can be found anywhere....
Frying it is no big deal....
Why , is another matter.....
Lets do this.....
In the pix below , you'll see R7324 is connected to G1 (Control Grid) to ground....

We need to figure out why that is frying...
So we are going to do a couple of checks....
#1=....
There is a medium thickness white wire (For focus) going to the top side of the Blue CRT module....
It goes to a connection near the socket....
It should just pull off the pin it is connected to....
Hang the wire AWAY from ALL other wires & especially metal parts....
The heavy Red wire I asked you to disconnect yesterday is to be left disconnected....
Put the CRT module back on the CRT & turn the TV on....
Keep your fingers AWAY from the white wire as it WILL have 5,~10,000 volts on it....
Check & see if R7324 is running hot....
Should NOT be....
Check the pix & see what it is/isn't doing....
Post results.....

#2=....
On the module near the corner opposite the white wire connection , you'll see 2
connectors that have 7 connections each....
On the pin farthest away (Pin #1) from the CRT socket is 200 vdc for the IC on that module....
With the TV on read that voltage & post results....

Question;=>...

Quote

No light codes noticed.

WHAT light codes ????...

Later...Ron.M.... Cool

....
Veteran & Retired TV technician

randomdes
New User

May 15, 2010, 12:20 AM

Post #5 of 25 (4067 views)
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Re: [Ron.M] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

There is no white wire, but I assume you meant the black one that plugs into the large plastic tube socket since thats the only non-colour coded wire that is easy to remove (and doesn't fry anything if i remove it. heh)

Anyway, with that removed, I don't get any more smoking from R7324.

While doing this test, I had a DMM hooked up from R7301 (+200v line) to ground, and read 300-400 volts (!!).

Quote

WHAT light codes ????...

The blinkenlight that gives me the status codes.

Ron.M
Veteran

May 15, 2010, 1:05 AM

Post #6 of 25 (4064 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

randomdes;....

OK , maybe wrong about the color....

Quote

While doing this test, I had a DMM hooked up from R7301 (+200v line) to ground, and read 300-400 volts (!!).

Whoaaa !!!...That's waaaay tooo high....
You want to re-check that ????....
Please re-check with the socket ON the CRT & OFF the CRT...
Give me better numbers than 300-400 volts...OK....
What kind of meter are you using ????...
Make & model , please....
With set OFF & UNPLUGGED , measure the ohms of R7324...
Post all readings & results...

Quote

The blinkenlight that gives me the status codes.

FYI;....Those are called "Error Codes"...

Later...Ron.M........
Veteran & Retired TV technician

randomdes
New User

May 15, 2010, 9:24 PM

Post #7 of 25 (4057 views)
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Re: [Ron.M] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Yep. I was a little suspicious about those numbers as well. Apparently my one DMM has lost its mind. So got out the BK 2707..

210 volts on the +200 volt rail. Both with board on and off the blue CRT.

Quote

measure the ohms of R7324...

Not sure if its relevant considering the above, but it reads a reasonable 10.8 ohms.

I also took a quick trip into the service manual to see what old codes the set has had. It must have been recently reset (likely following your instructions to EL a few months ago. It lists one event of each:

akb, HV and low B

So I cleared the codes, and none return in its current state (blue HV and the one focus connection disconnected, everything else connected)

jts1957
Veteran

May 15, 2010, 9:37 PM

Post #8 of 25 (4055 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

R7324 = 1K = 1,000 ohms Cool

-------------------------
Location: Far, Far Away

(This post was edited by jts1957 on May 15, 2010, 9:38 PM)

randomdes
New User

May 15, 2010, 10:10 PM

Post #9 of 25 (4051 views)
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Re: [jts1957] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Oops. sorry mental goof.

I thought you were talking R7304, since it was my test point.

Yes, I've been watching R7324 since it's been smoking on me. Its still 1k ohms (978 to be exact.)

(This post was edited by randomdes on May 15, 2010, 10:10 PM)

Ron.M
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May 15, 2010, 10:55 PM

Post #10 of 25 (4042 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

randomdes;....

Quote

Oops. sorry mental goof...I thought you were talking R7304, since it was my test point.

I think you made another one....Test point for WHAT ????....
R7304 is 560k 1/2 watt going to G2 on the blue CRT....
IF you have the same service manual as I do , look on page 57....
On that page also is the layout for the Blue CRT module...
In the upper right corner of the page is a drawing of the module....
On the module , bottom , center is a connector CN7304 (Sound familiar ???) that goes
to Ta Da >> R7304....
Disconnect that connector....Hang the wire away from any parts OR metal....
Re-connect the focus wire back where it was....
Leave the Red HV wire OFF....
Hook up the module to the CRT & turn the TV on....
Watch R7324 for overheating....

Post results....

Later...Ron.M.... Cool

....
Veteran & Retired TV technician

randomdes
New User

May 15, 2010, 11:38 PM

Post #11 of 25 (4038 views)
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Re: [Ron.M] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Agh you're right. Im not doing so well these days :/

Yes, that was a typo, i meant to say R7301, what i was clipping my leads on to to measure the +200v rail.

With CN7304 removed, focus back on, and HV still off, I dont get any overheating from R7324

Ron.M
Veteran

May 15, 2010, 11:57 PM

Post #12 of 25 (4036 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

randomdes;....

OK, forgiven.... Wink

....

Lets go back to square one....
Hook up EVERYTHING as it was & turn the TV on...
Watch R7324 for overheating again...

Post results....

FYI;=>....
I'll be offline for about 3 or more hours...
Will reply either late tonite OR tommorrow....

PS:...
Let me know what the pix is doing....Thanks.... Sly

...

Have a GOOD evening....

Later...Ron.M.... Cool

....
Veteran & Retired TV technician

(This post was edited by Ron.M on May 16, 2010, 12:01 AM)

randomdes
New User

May 16, 2010, 1:17 AM

Post #13 of 25 (4028 views)
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Re: [Ron.M] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Hooked everything back up, turns out the hot resistor was a wild goose chase caused by my missetting of the screen adjustment on the focus block.

and the blue flashes are almost gone. Weird!

With a little bit of screen tweaking on the focus block, the blue flashes seem mostly gone.

(This post was edited by randomdes on May 16, 2010, 6:20 PM)

jts1957
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May 16, 2010, 3:21 AM

Post #14 of 25 (4026 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Quote

Which to my uneducated eye looked like a screen bias adjustment issue. So I got it home, turned down the screen bias, and the TV flashes less, and doesn't shut down, but it started smelling nasty. On further inspection, R7324 was starting to burn up.

You should have mentioned you turned UP the screen bias (not down). Angelic

-------------------------
Location: Far, Far Away

randomdes
New User

May 16, 2010, 3:41 AM

Post #15 of 25 (4023 views)
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Re: [jts1957] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

A lack of understanding of bias adjustment I guess.

I turned it counter-clockwise. Clockwise too far causes the picture to saturate with the given colour, so I assumed that was higher bias.

Do I have it backwards?

Ive been watching the tv for a couple hours now. The blue level is flickering slightly, and I still get the occasional bright blue flash. So something is still wrong. But for the most part it looks ok.

jts1957
Veteran

May 16, 2010, 3:55 AM

Post #16 of 25 (4021 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Having the bias adjustments too high (CW) was what was causing? Turning one (or more) down (CCW) was what stopped it?

-------------------------
Location: Far, Far Away

randomdes
New User

May 16, 2010, 5:20 AM

Post #17 of 25 (4018 views)
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Re: [jts1957] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Bias too far CCW caused the resistor to burn. I had turned the bias down to try and eliminate the bright flashing issue. I had left it all the way CCW during all this other testing and that's why the resistor kept heating up.

randomdes
New User

May 16, 2010, 6:19 PM

Post #18 of 25 (4011 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Update. Put a few more hours on the set.

Still get the occasional bright blue flash, and the blue level continues to 'flicker' slightly.

Ron.M
Veteran

May 16, 2010, 8:36 PM

Post #19 of 25 (4005 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

randomdes;.....

Here's the scoop;....
R7324 is the control grid bias resistor....
Overheating of this resistor indicates short in Blue CRT....
Arcing stopped when you disconnected Red HV wire....
Indicates short in Blue CRT....
By us disconnecting various wires & turning the TV on may
have temporarily allieviated the problem....
Rest assured , it's STILL there.... Unsure

...
Based on what you have done & what the TV is doing , I have come to the conclusion
that the Blue CRT is bad.... Unsure

....

When you get the "occasional bright blue flash" the short is trying to re-assert itself....
By putting more hours on the TV it's impossible to tell which way it's going to go....
Better(?) OR worse.... Unsure

....

SORRY to be the bearer of bad news , but at times , honesty hurts....

Dats it for now , see ya at KP-43T75.....

Later....Ron.M... Cool

....
Veteran & Retired TV technician

randomdes
New User

May 16, 2010, 9:07 PM

Post #20 of 25 (4002 views)
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Re: [Ron.M] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Thanks, that's what I figured from our diagnosis roundabout.

The more I run it, the better it seems to get. So maybe all the shaking and rewiring gave it a second wind.

There is a person selling a blue tube for this set locally, supposedly NIB, for about $80. If the set runs well for a bit then shorts out, I might give them a call.

Is the crt changeover something I can do with tools at hand? that is, without any additional calibration equipment or anything. As i assume a new CRT inside the magnetics means new calibration.

jts1957
Veteran

May 16, 2010, 9:15 PM

Post #21 of 25 (4000 views)
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Re: [Ron.M] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Presuming its a heater to cathode short, what about wiring a heater isolation/booster transformer? Cool

-------------------------
Location: Far, Far Away

Ron.M
Veteran

May 16, 2010, 9:50 PM

Post #22 of 25 (3996 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

jts1957....
I don't know that a heater isolation/booster transformer is going to work here...
Reason is that R7324 was overheating & the CRT was arcing....
I think its a HV short inside the CRT...
IF he had a heater to cathode short , his symptoms would be different....

Thanks....

randomdes;....

Quote

The more I run it, the better it seems to get. So maybe all the shaking and rewiring gave it a second wind.

More like a second puff....

Quote

Is the crt changeover something I can do with tools at hand? that is, without any additional calibration equipment or anything. As i assume a new CRT inside the magnetics means new calibration.

I forgot your electronic credentials....
You shouldn't need any specialized tools for this job....
There are NO "inside magnetics" that means calibration....
You may have to do some re-convergence adjustments , but that's normally NO big deal....
You will/may have to replace some coolant , tho.....

Quote

There is a person selling a blue tube for this set locally , supposedly NIB

What is NIB ???....
Make SURE the CRT model #'s are EXACT !!!!...

Later...Ron.M.... Cool

....
Veteran & Retired TV technician

jts1957
Veteran

May 16, 2010, 9:56 PM

Post #23 of 25 (3993 views)
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Re: [Ron.M] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

NIB New In Box My guess!
NIB Nordic Investment Bank
NIB National Industries for the Blind
NIB National Irish Bank
NIB News in Brief
NIB National Institute of Biology (Ljubljana, Slovenia)
NIB National Insurance Board
NIB N�mero de Identifica��o Banc�ria
NIB Network Interface Board
NIB Nativity In Black
NIB Next Interface Builder (software development application)
NIB National Irrigation Board (Philippines)
NIB Non-Interference Basis
NIB Non-Interest-Bearing
NIB Network Interface Backup
NIB No International Bidders (eBay)
NIB NATO Intelligence Board
NIB Newly Initiated Brother (fraternities)
NIB Not-to-Interfere-Basis
NIB Not in Budget
NIB Nuova Italia Bibliografica
NIB Not in Bin
NIB NIMA Integration Board
NIB Notified Inspection Body
NIB Navigation Information Bulletin
NIB Naval Infantry Brigade
NIB National Intelligent Bureau
NIB Norwich Independent Battery (Northfield, Vermont)

-------------------------
Location: Far, Far Away

randomdes
New User

May 16, 2010, 10:40 PM

Post #24 of 25 (3989 views)
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Re: [Ron.M] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

Quote

I don't know that a heater isolation/booster transformer is going to work here...

Aw. i had my hopes up for a brief second. heh

I guess if my short is to the first grid, then allowing it to float isn't much of an option. hehe.

Quote

I forgot your electronic credentials....
You shouldn't need any specialized tools for this job....

I'm an E.Eng. limited experience with CRT/tubes though, couple TVs, couple radios. Mostly I do embedded/microprocessor stuff.

I thought perhaps the remounting of deflection coils might require more calibration than simply convergeance. The manual waxes lyrical about test video signals and oscilloscopes and such.

Quote

What is NIB ???....

Apologies, thought this was well known. Yes new in box.

Quote

Make SURE the CRT model #'s are EXACT !!!!...

I know ;) Yes its exactly the same one.

(This post was edited by randomdes on May 16, 2010, 10:45 PM)

Ron.M
Veteran

May 16, 2010, 11:20 PM

Post #25 of 25 (3984 views)
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Re: [randomdes] Sony KP-46WT500 Flashes Blue, 8 blinks. [In reply to]	Can't Post

randomdes;....

Quote

The manual waxes lyrical about test video signals and oscilloscopes and such.

IF & when you do decide to get & install the new CRT , don't worry about what the service manual says about convergence....
Us old farts know a short cut or two....
Just post OR PM....

Have a GREAT day.....

Later...Ron.M.... Cool

....
Veteran & Retired TV technician

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