Sony Bravia LCD KDL-32L4000

[Kevin O'Henly]

Symptoms:
~ no panel lamps
~ SER tests showed no bad caps this time and no bulging caps visible
~ all fuses test ok

See attached block diagram from service manual.
Service manual can be downloaded after registering with the site: http://www.scribd.com/doc/21548740/C...00-KDL-37L4000

Board-G is the SMPS
Board-A is the video control board

~ board-G, CN202: "4VSB" pins 3, 7 & 8 have 4Vdc

~ other power outputs: 6Vdc, 15Vdc, 30Vdc, 24Vdc & Board-G, CN201,pin7&8 "PWR_PANEL" are at 0Vdc

~ "POWER ON" signal at Board-A(CN1 pin 13) and also "PS-ON" at Board-G(CN202 pin 1) are connected and at a logic low(0Vdc). The "PS-ON" signal originates from the controller IC on Board-A.

~ "PWR_ERR_DET" on Board-G, CN202-pin2 & Board-A, CN1,pin15 are 0Vdc

~ I verifyed the operation of the power button input at Board-A, CN4

This power supply has been a real head-scratcher, folks.

Because the "PS-ON" signal originates from the controller IC on Board-A the defect could be on Board-A. I would like to verify the power supply before replacing the controller board (Board-A).

Is there any way to verify the power supply board on its own?

Any advice would be greatly appreciated.
Thank you.

rgs,
Kevin

[PlainBill]

Re: Sony Bravia LCD KDL-32L4000

Symptoms:
~ no panel lamps
~ SER tests showed no bad caps this time and no bulging caps visible
~ all fuses test ok

See attached block diagram from service manual.
Service manual can be downloaded after registering with the site: http://www.scribd.com/doc/21548740/C...00-KDL-37L4000

Board-G is the SMPS
Board-A is the video control board

~ board-G, CN202: "4VSB" pins 3, 7 & 8 have 4Vdc

~ other power outputs: 6Vdc, 15Vdc, 30Vdc, 24Vdc & Board-G, CN201,pin7&8 "PWR_PANEL" are at 0Vdc

~ "POWER ON" signal at Board-A(CN1 pin 13) and also "PS-ON" at Board-G(CN202 pin 1) are connected and at a logic low(0Vdc). The "PS-ON" signal originates from the controller IC on Board-A.

~ "PWR_ERR_DET" on Board-G, CN202-pin2 & Board-A, CN1,pin15 are 0Vdc

~ I verifyed the operation of the power button input at Board-A, CN4

This power supply has been a real head-scratcher, folks.

Because the "PS-ON" signal originates from the controller IC on Board-A the defect could be on Board-A. I would like to verify the power supply before replacing the controller board (Board-A).

Is there any way to verify the power supply board on its own?

Any advice would be greatly appreciated.
Thank you.

rgs,
Kevin

Dang, you get interesting problems.

I see three ways to proceed.

1. Test the power supply by providing the proper loads and driving PS_ON high.

2. Isolate the PS_ON line from the controller and drive it high. This uses the circuit boards as the load.

3. Wait for Wizard.

I'd bet on the A board as the culprit. If it were good it should drive the standby LED on. This logic is tenuous at best.

PlainBill

[Kevin O'Henly]

Re: Sony Bravia LCD KDL-32L4000

Hi PlainBill,
I like method 2 because it's easy,

With this in mind I poped pin13 out of the cable connector at Board-A, CN1, pin13 "POWER-ON". POWER-ON becomes "PS-ON" on Board-G, CN202, Pin1. The "POWER-ON" is generated by the Board-A controller IC.

[PlainBill]

Re: Sony Bravia LCD KDL-32L4000

Hi PlainBill,
I like method 2 because it's easy,

With this in mind I poped pin13 out of the cable connector at Board-A, CN1, pin13 "POWER-ON". POWER-ON becomes "PS-ON" on Board-G, CN202, Pin1. The "POWER-ON" is generated by the Board-A controller IC.

And does the power supply now provide all output voltages?

PlainBill

[Kevin O'Henly]

Re: Sony Bravia LCD KDL-32L4000

Actually, no.

With the "PS-ON" lead floating when AC power is applied then the 4VSB (4Vdc stand-by) is not generated. This is due to RL1 normally open contacts not closing. Which seems to be due to "PS-ON" being disconnected. I think?

OOps!

I just tried method one. With "PS-ON" clipped to Board-A, CN1, Pin13.
I had a probe slip and fried Q3 (2sk3568 mosfet, schematic 1of2, position A-8) so I do not have a measure of the floating voltage of the "PS-ON" lead but I seem to recall that it was 4-5Vdc.

In the mean time I started tracing "PS-ON" which comes from "PWON#" on Board-A. see PSON.png

It seems that the surface mounted resister, R53 is missing. By the smooth solder mounds at the component location I would guess that the resister was never on the board to begin with. ???

Still tracing...

The "Power_On" signal comes directly from the micro-controller IC, U18. R53 & R59 are a voltage divider that should maintain Power_on at 2Vdc when the 4Vdc stand-by is on. R52 is a current limiter for Q12.

I am guessing that the U18 output "Power_On" is open collector (active low). If "Power_On" is active high then "PWON#" is active low.

Is the "#" sign Sony's way of indicating active low?

"PWON#" goes through a 0 ohm resistor (jumper) to CN1, pin 13 and then over to Board-G (power supply) as "PS-ON".

If the micro-controller is pouched then Board-A would have to be replaced.

That's all fine (not great as it was probably a manufacturing defect) but does not explain why the power supply resists being tested in isolation.

rgs,
Kevin

[koppit]

Re: Sony Bravia LCD KDL-32L4000

I have the same TV, but my problem is the relay keeps clicking in and out. I don't see any visible bad caps, and the voltage out, where it's supposed to be 80v, goes up for a few seconds, I hear the click of the relay, and it drops back down to 0v. The actual power supply board is model PSE-324 (1-468-721-1) .. I read what you have above, must be a different PSU board in my TV, because the connectors out are CN23 and CN33.

I've attached pictures, because quite frankly, I'm lost. Usually I can just point out the bad caps and replace them, and my job is done. This is also FAR more complicated than any LCD monitor I've taken apart. Recently I picked up a capacitance tester, but I can't seem to make heads or tails of it, either - it gives me different values than my multimeter set to test for continuity, and nothing seems consistent.

Anyways, first picture on the left, near the top input voltage connector, is the blue relay that kicks in and out. The top right are the two connectors that should read 80v on the bottom 3 of each. They power the two side boards.

Hoping someone can help

[koppit]

Re: Sony Bravia LCD KDL-32L4000

Anyone? :p

[Wizard]

Re: Sony Bravia LCD KDL-32L4000

Reconnect everything correctly and disconnect the PWR_ERR_DET. This should be floating high all the times. This could be detected as bad and A board refusing to turn on except it should blink out a error code.

Ideally measure voltage of this PWR_ERR_DET connected or disconnected on the G board.

Please monitor the PS_on or like to the SMPS (G board). Every time power button is pushed, should go up high or go low. Otherwise disconnect the PWR_ERR_DET and try again with your meter. If works, then probe all the other voltage outputs of the power supply.

Do not forget to ohm the outputs to insure there's no short. I just fixed generic tv today. FSP SMPS was fixed and did not fix the TV and found another part that was damaged by overvoltage in mainboard.

PS: please repost the pic of main SMPS in better detail, so I can look at it.

Cheers, Wizard

[koppit]

Re: Sony Bravia LCD KDL-32L4000

No problem Wizard, I appreciate the response. I will take better pictures this evening and upload them. As for the PWR_ERR_DET, keep in mind my TV has a different board than Kevin's does - but I will measure the voltage output on the AC Input board, and try to find a schematic for that TV.

[koppit]

Re: Sony Bravia LCD KDL-32L4000

http://codingconcepts.net/tv/

I've uploaded some better pictures at the above address, but for some reason I can't find my memory card or card reader for my actual digital camera, so I'm stuck with my blackberry pictures. I was unable to find a schematic, either.

[crtfool]

Re: Sony Bravia LCD KDL-32L4000

http://codingconcepts.net/tv/

I've uploaded some better pictures at the above address, but for some reason I can't find my memory card or card reader for my actual digital camera, so I'm stuck with my blackberry pictures. I was unable to find a schematic, either.

To koppit - This thread is for a KDL-32L4000 LCD TV, but you link to pictures is for a KE-32TS2U PLASMA TV. I am confused as to what TV you are talking about. My research shows that these 2 TV's have completely different power supplies - the Plasma has the PSE-324 ORION power supply. I have a KE-32TS2U with a bad power supply that I need help with identifying some components that were damaged by it's previous owner. If the KDL-32L4000 does in fact have the same PSE-324 ORION power supply, can you please confirm this.

Or, if anyone else can verify this info, it would be greatly appreciated.

Thanks.

[Wrog]

Re: Sony Bravia LCD KDL-32L4000

To koppit - This thread is for a KDL-32L4000 LCD TV, but you link to pictures is for a KE-32TS2U PLASMA TV. I am confused as to what TV you are talking about. My research shows that these 2 TV's have completely different power supplies - the Plasma has the PSE-324 ORION power supply. I have a KE-32TS2U with a bad power supply that I need help with identifying some components that were damaged by it's previous owner. If the KDL-32L4000 does in fact have the same PSE-324 ORION power supply, can you please confirm this.

Or, if anyone else can verify this info, it would be greatly appreciated.

Thanks.

I have a KDL-32L4000 that I'll be taking apart soon-ish, maybe this weekend. I'll post pictures of the power supply.

[crtfool]

Re: Sony Bravia LCD KDL-32L4000

Thanks Wrog - Very much appreciated. I also just noticed that I incorrectly wrote "ORION" as the manufacturer - it is supposed to be "ORIGIN ELECTRIC CO., LTD"

[Wrog]

Re: Sony Bravia LCD KDL-32L4000

Unfortunately, I did not get to it this weekend. Here's to hoping I have time this coming weekend!

[Wrog]

Re: Sony Bravia LCD KDL-32L4000

The power supply for the KDL-32L4000 is a Delta EADP-170AF A. All Rubycon and Nichicons!

[crtfool]

Re: Sony Bravia LCD KDL-32L4000

Thanks Wrog - your power supply is exactly what I expected. I think that koppit is working on the same Plasma TV that I am - not sure why he posted in this thread.

My search for info led me to this thread, so I was hoping that there would be another TV with the PSE-324 - unfortunately it turned out to be a RED HERRING!

I have had zero luck getting info on my power supply, so the adventure continues.....

[Kevin O'Henly]

Re: Sony Bravia LCD KDL-32L4000

Hi all.

I am back (originator of the thread) to look at restoring function to the KDL-32L4000.

The Delta EADP-170AF A SMPS is what I was interested in fixing.

Since my last post I have discovered that this SONY LCD TV has been kicked around the block before I received it. The connector between the CCFLs and inverter board was missing and while an inverter board was in the case it had nothing to do with this set. The set will need the inverter board.
Yep! ...a mess.
All that being so I still desire to repair the SMPS. Fixing the SMPS will not fix this LCD TV but perhaps down the road the remaining parts will emerge. After all; my goal is to keep devices out of the land-fill and fixing them is the best way I know to achieve this outcome.
In the Zen sense I am back to where I started but with greater insight.
I am ignorant; not stupid. My ignorance is fixable with the aid of a guide who is wiser than I.

gratefully...

[Wrog]

Re: Sony Bravia LCD KDL-32L4000

Kevin, I think between the two of us, we have one complete TV! Yours is missing the SMPS (G board), inverter and some cabling, while mine either has a borked signal board (A board), TCON or panel.

Let me know if I can supply any measurements or component values to aid in your recovery project.

[Kevin O'Henly]

Re: Sony Bravia LCD KDL-32L4000

Thank you Wrog.
This should be fun and an interesting thread development but we will likely not have working TV's at the end of the day.

There is a link at this thread start to download a schematic for the Sony Bravia LCD KDL-32L4000 if you need it?

It would be usefull to troubleshoot any and all SMPS stand alone. Yes?
Get the PS working then load it up and see what happens electronically.

As you have a good PS perhaps could we try an experiment to determine if board-g will come out of standby with no load when "PS-ON" at Board-G(CN202 pin 1) is set to a logic high. A shorting strap between board-G connector CN202 pins 1 and 3 (4Vsb) should do it. PWR_ERR_DET ( CN202 pin 2 ) should be floating high as there is nothing connected to it when all the connectors are removed from board-g.

If board-g comes out of standby with no-load then I would expect CN203 pins 5 through 10 to read 24Vdc, CN201: pins 3 & 4 to read 6Vdc, pins: 11 & 12 to read 15Vdc and pin 14 to read 30Vdc. What voltage reading do you get for "PWR_PANEL" at pins 7 & 8?

Safety is paramount. If you are not comfortable trying this then it is best not tried.

[Fred Raines]

Re: Sony Bravia LCD KDL-32L4000

I have a Sony Bravia LCD KDL-32L4000. It's 15 months old. Recently it failed to power up from the remote. The Power LED was on. The screen was black. The power switch had no effect. It did not turn on or off with the power switch.

The unit was unplugged from the wall and left overnight. It powered on the next day. We left it on for several days and powered off the cable box to "turn off the tv". Now it won't power on at all. The power LED is on when the unit is plugged into the wall outlet. The screen is black.

There are no visible burned or deformed caps (or other components) on the A (CPU) or G (power supply) boards. All voltages on the G board match the service manual. I measure 11.8 VDC on the PWR_PANEL lines of the CN201 connector. I measure 0.09VDC on the PS-ON line at connector CN202. I lifted the PWR_ERR_DET line at the CN202 connector on the G board. This had no effect.

Does anyone know what the USB port on the CPU board is for? It is marked Service. I assume it is for diagnostics. What program is used?

I appreciate in advance any insight into the problem. I hate to trash a $600 TV.