Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting TVs and Video Sources
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 08-03-2016, 07:06 PM   #1
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Sony KDL-46VE5 - no power, no standby or LED

This time around, I'm hoping I can save some friends from having to buy a new set. Their TV is the Sony Bravia KDL-46VE5 [mfr link] - one day it just wouldn't turn on, and no LEDs were lit. There was no known physical trauma or input power issue.

I've opened it up and blown the dust off, and done some minor poking around with a DMM... The only thing I've really determined is that there's no standby power / no voltages going to the main board. The main fuse is good, the power button and phantom-drain/eco-switch are also fine, and none of the (mostly Rubycon) caps are bulging. I'm guessing this points to a power supply issue.

As such, here are some photos of the power PCB, part 8-597-105-11 / board 1-878-773-23:



The main PCB on this one is board A-1641-795-A or 1-879-239-13 (shopjimmy lists the latter number as 1-879-239-12, but the other one matches). Didn't have a chance to remove this board or take photos.

I'd really appreciate if anyone is able to help out - and let me know if more or better photos are needed.
Attached Images
File Type: jpg KDL-46VE5-PSU-front.jpg (1.59 MB, 492 views)
File Type: jpg KDL-46VE5-PSU-back.jpg (1.85 MB, 488 views)
gintama is offline   Reply With Quote
Old 08-05-2016, 04:42 PM   #2
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Re: Sony KDL-46VE5 - no power, no standby or LED

I can't edit the first post any more, but I forgot to mention I'm looking to repair the problem board rather than replace it. It's a 2009 set and boards are scarce/expensive.

Additional photos - the main board and overall layout.



Attached Images
File Type: jpg KDL-46VE5-MB-front.jpg (988.9 KB, 479 views)
File Type: jpg KDL-46VE5-MB-back.jpg (1.25 MB, 473 views)
File Type: jpg KDL-46VE5-layout.jpg (969.9 KB, 485 views)
gintama is offline   Reply With Quote
Old 08-05-2016, 06:56 PM   #3
CapLeaker
Leaking Member
 
CapLeaker's Avatar
 
Join Date: Dec 2014
City & State: Atlantic Canada
My Country: Canada
Line Voltage: Ground, 0Hz
I'm a: Hobbyist Tech
Posts: 6,013
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Since you got no 3.3V STBY voltage, do you have 170V DC on the main filter caps?

First picture top right, there is a silver heat sink. On the left of the heatsink there is a small transformer and a small IC. That is the stby section in the primary. I think the IC is IC6200. What is printed on that IC?

Last edited by CapLeaker; 08-05-2016 at 07:09 PM..
CapLeaker is offline   Reply With Quote
Old 08-05-2016, 07:10 PM   #4
R_J
Badcaps Veteran
 
Join Date: Jun 2012
City & State: ☻
My Country: Canada
I'm a: Professional Tech
Posts: 9,057
Default Re: Sony KDL-46VE5 - no power, no standby or LED

I believe the standby (primary) circuit is what I outlined in yellow, check the number on the ic to get what the voltages should be, also check the resistors (in red) R6016 (does go open sometimes) and check R6200 & R6202, I think they supply voltage for the standby ic.
If measuring voltage you should have around +160 accross C6503 or C6501, If you have that voltage (negative probe to - of c6503) you should have close to the same voltage at R6200 and then at R6202 and then at pin 5 of ic6200
Attached Images
File Type: jpg KDL-46VE5-PSU-front.jpg (401.8 KB, 86 views)

Last edited by R_J; 08-05-2016 at 07:22 PM..
R_J is offline   Reply With Quote
Old 08-05-2016, 09:08 PM   #5
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Re: Sony KDL-46VE5 - no power, no standby or LED

IC6200 is a Panasonic MIP2H2. The datasheets all seem to be for complete power supply circuits, but I found a document on Scribd titled "Sony Training Manual Chassis WAX2T" which shows the following table:
Code:
Pin | Function | vDC  | vAC/Hz
1     VDD        6V
2     FB         1.8V
3     OLP        0V
4     VCC        13V
5     DRAIN      390V   ~500p-p ( 45kHz )
7-8   SOURCE     GND
"This circuit develops two voltages, 3.3v STBY voltage for devices such as main uPC, EMMA processor, IR receiver; and 17.5v for main converter (controlled by Power On line)".

The two axial resistors (R6500/.47Ohm and R6200/10Ohm) are within parameters.

This rectangular one next to the relay (R6016/6.8Ohms) reads ~35MOhm or nothing at all, which I take it means it has failed open.


I didn't get to any powered tests tonight. Are the previously suggested ones still needed? If so I'll get to them in the morning.
Attached Images
File Type: jpg R6016.jpg (18.4 KB, 477 views)

Last edited by gintama; 08-05-2016 at 09:10 PM..
gintama is offline   Reply With Quote
Old 08-05-2016, 09:29 PM   #6
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 39,206
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Start checking for shorted parts in the primary side.
That resistor/thermal fuse is for inrush current limiter, it is bypassed when relay RY6000 is turned on, if the relay contacts are bad then that resistor will not be bypassed so it will burn open circuit when TV is trying to pull full current.
So look for shorts first, then the relay contacts (more difficult to check).
Since that resistor is open so you will not have AC feeding the bridge rectifier.
__________________
Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956

Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999

Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl

Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/

TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809

Last edited by budm; 08-05-2016 at 10:46 PM..
budm is offline   Reply With Quote
Old 08-06-2016, 05:51 AM   #7
CapLeaker
Leaking Member
 
CapLeaker's Avatar
 
Join Date: Dec 2014
City & State: Atlantic Canada
My Country: Canada
Line Voltage: Ground, 0Hz
I'm a: Hobbyist Tech
Posts: 6,013
Default Re: Sony KDL-46VE5 - no power, no standby or LED

it does happen that just the "inrush current limit resistor" fails (but then you would have to look hard at the relay). But I would definitely check if there isn't a short in the primary or the fact of a bad relay as budm suggested.

Last edited by CapLeaker; 08-06-2016 at 05:52 AM..
CapLeaker is offline   Reply With Quote
Old 02-07-2017, 11:58 AM   #8
ernest79336
New Member
 
Join Date: Aug 2016
City & State: Levelland
My Country: United States
I'm a: Knowledge Seeker
Posts: 5
Default Re: Sony KDL-46VE5 - no power, no standby or LED

I have the exact set same problem i took the cover off the relay and it will turn on if i manually push down on the relay to make it connect so is it bad?
ernest79336 is offline   Reply With Quote
Old 02-07-2017, 12:32 PM   #9
dick_barton
Badcaps Veteran
 
dick_barton's Avatar
 
Join Date: Aug 2015
City & State: Cardiff
My Country: Wales
Line Voltage: 230V AC, 50Hz
I'm a: Hobbyist Tech
Posts: 6,544
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Have you checked the resistors identified above?
__________________
Willing to help but I'm no expert.
dick_barton is offline   Reply With Quote
Old 02-07-2017, 12:47 PM   #10
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Re: Sony KDL-46VE5 - no power, no standby or LED

I replaced the fusible resistor (R6016) on mine but there was no change. I couldn't find a suitable replacement for the relay in my parts bins so that's as much as I've had time for so far.

ernest79336, can you show a picture of the uncovered relay? I didn't realize you could do that without destroying them or I would have tried it!
gintama is offline   Reply With Quote
Old 02-10-2017, 06:20 PM   #11
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Oh my. That was... embarrassingly simple. After ernest's post above, I took a closer look at the relay, to find that there's a clearly visible line where the housing goes on, and even large clips showing it's intended to be removed. I gently pressed on the side of the housing to see how loose it was - and it just popped off. I had no idea they weren't sealed units.

So I verified all the connections were in order, applied power, and manually closed the relay... After hitting the power button, the set lit up fine. Plugged in a old game system, audio and video seem normal.

Not sure what to do now. As I understand it, this narrows down the problem to the stand-by circuit. That relay connects the 120V lines, so as a last resort I could rewire the "Power Saving" switch on the TV to manually bridge that connection (instead of breaking the 120V circuit before the power supply like it does now). I'd prefer to fix it properly though...
gintama is offline   Reply With Quote
Old 02-10-2017, 11:52 PM   #12
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Taking some measurements, finally.

Quote:
Originally Posted by R_J View Post
I believe the standby (primary) circuit is what I outlined in yellow, check the number on the ic to get what the voltages should be, also check the resistors (in red) R6016 (does go open sometimes) and check R6200 & R6202, I think they supply voltage for the standby ic.
If measuring voltage you should have around +160 accross C6503 or C6501, If you have that voltage (negative probe to - of c6503) you should have close to the same voltage at R6200 and then at R6202 and then at pin 5 of ic6200
No voltage across the two large caps (C6503/C6501), or the nearby resistors (R6200/R6202), same at IC6200 pin 5. R6202 has a resistance of about 36 kOhm, but I'm not sure what it should be - the only legible markings say 1 Watt and 104 J.

With the TV plugged in (but the relay not closed), IC6200 reads 1.15VDC at pin 1, and 0.24VDC at pin 4. With the relay closed, these read 6VDC and 11VDC respectively, which are near spec.
gintama is offline   Reply With Quote
Old 02-11-2017, 12:20 AM   #13
dskall
Badcaps Veteran
 
dskall's Avatar
 
Join Date: Oct 2016
City & State: Bakersfield ca.
My Country: usa
Line Voltage: 120VAC 60Hz
I'm a: Knowledge Seeker
Posts: 2,901
Default Re: Sony KDL-46VE5 - no power, no standby or LED

I had same problem cleaned the contacts on the relay with a business card and still working.
dskall is offline   Reply With Quote
Old 02-11-2017, 01:35 AM   #14
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Thanks for the suggestion, but with no power to activate the relay, I doubt the condition of the contacts is much of an issue.
gintama is offline   Reply With Quote
Old 09-05-2017, 02:18 PM   #15
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Well, this project sat on the workbench long enough, here is the final outcome.

I found multiple places that still had stock of the needed power PCB, most at a cost of USD ~$100 with shipping to Canada. Most had exactly the same quantity available, so were probably just storefronts with the same supplier. My friend wasn't sold on putting that much money into an old TV and possibly still ending up with it not working, so I proceeded with my earlier plan.



The lower trace to CN6003 (the Energy Saving Switch) was severed, and a jumper was added to connect that point to one of the relay contacts (RY6000, just above the "R"). The upper point of CN6003 is already connected to the other relay contact. Finally, a jumper was connected between the two nearby test points, JL6523 & JL6524 to replace the switch.

When the Energy Saving Switch is ON, the TV's standby LED comes on and the unit behaves as expected. When the switch is OFF, there's no standby power and the remote cannot turn on the TV. Once the TV is turned on, the relay closes normally, so you could move the switch to the OFF position and nothing would happen. Power usage appears unchanged, about 3W in standby regardless of the position of the switch. The switch itself is sort of redundant in this configuration, but I thought it best to have a way to bypass the hack in case the unit is left unattended for a long period of time but not unplugged.
Attached Images
File Type: png final-fix.png (112.2 KB, 394 views)
gintama is offline   Reply With Quote
Old 09-05-2017, 08:11 PM   #16
R_J
Badcaps Veteran
 
Join Date: Jun 2012
City & State: ☻
My Country: Canada
I'm a: Professional Tech
Posts: 9,057
Default Re: Sony KDL-46VE5 - no power, no standby or LED

See if this is any help
Attached Files
File Type: pdf sony_1-878-773-22_power_sch.pdf (1.65 MB, 115 views)
R_J is offline   Reply With Quote
Old 09-05-2017, 08:19 PM   #17
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Hah, yeah that would probably be quite helpful! I'll take a look, thanks.
gintama is offline   Reply With Quote
Old 01-23-2018, 04:00 PM   #18
jeffinpeggs
New Member
 
Join Date: Jan 2018
City & State: Peggs, Oklahoma
My Country: United States
I'm a: Knowledge Seeker
Posts: 1
Thumbs up Re: Sony KDL-46VE5 - no power, no standby or LED

I would like to thank you all for your input, and especially gintama for the bypass instructions and photo. I had the same problem and after testing I found one bad cap. After replacing it I still had no power and stumbled upon this forum and post. Tv is now working after applying the bypass, Thank you very much.
jeffinpeggs is offline   Reply With Quote
Old 01-23-2018, 04:57 PM   #19
gintama
Member
 
gintama's Avatar
 
Join Date: Sep 2007
Posts: 51
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Quote:
Originally Posted by jeffinpeggs View Post
Thank you very much.
I'm glad to hear it helped. Thank you for reporting back about it. I wonder how many more of these sets have failed this way...
gintama is offline   Reply With Quote
Old 10-31-2018, 11:02 AM   #20
RyanM
New Member
 
Join Date: Oct 2018
City & State: Milwaukee, WI
My Country: USA
I'm a: Knowledge Seeker
Posts: 3
Default Re: Sony KDL-46VE5 - no power, no standby or LED

Which relay is that?

Quote:
Originally Posted by gintama View Post
Oh my. That was... embarrassingly simple. After ernest's post above, I took a closer look at the relay, to find that there's a clearly visible line where the housing goes on, and even large clips showing it's intended to be removed. I gently pressed on the side of the housing to see how loose it was - and it just popped off. I had no idea they weren't sealed units.

So I verified all the connections were in order, applied power, and manually closed the relay... After hitting the power button, the set lit up fine. Plugged in a old game system, audio and video seem normal.

Not sure what to do now. As I understand it, this narrows down the problem to the stand-by circuit. That relay connects the 120V lines, so as a last resort I could rewire the "Power Saving" switch on the TV to manually bridge that connection (instead of breaking the 120V circuit before the power supply like it does now). I'd prefer to fix it properly though...
RyanM is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2023
Powered by vBulletin ®
Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 09:34 PM.
Did you find this forum helpful?