Sony KDL40W4100: no signs of life?

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

Should I use an iron or a heatgun? It looks like there's a lot of them on here.

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

I tried using a heat gun on the back of the main board but no dice, I'll try an iron on the larger caps this evening. I was able to confirm the backlight works by hooking it to my brothers KDL40S4100 so if I need to buy a new main board I'm not as worried as I would be if I couldn't have tested that.

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

How do I determine which numbers matter for ordering a new main board? From what I can tell A1506072C and 1-876-561-13 are the relevant ones, but can I use one from a KDL-52W4100?

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

Bringing this back up, according to Shop Jimmy I need an "A-1643-237-A" board, however I can't find one anywhere. Nobody on eBay seems to be able to confirm the serial number or panel number of the TVs they pull boards from, can anyone tell me if there's anywhere else that I can see if the board is cross compatible with another one? Failing that, anyplace I might be able to send this board for repair?

From ShopJimmy:
Part Number: A-1643-237-A
Board Number(s): 1-876-561-13, A1506072C
Panel Sticker Number: LTY400HF01
Panel Manufacturer: Samsung
Important Message: BU Board 8200001-8400000

My TV serial number is actually higher than that (844xxxx), but from what I can tell Sony doesn't put the part number anywhere on the actual board?

[ozzy214]

Re: Sony KDL40W4100: no signs of life?

You didnt look to hard

http://www.ebay.com/sch/i.html?_from...13%2C&_sacat=0

40 usd

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

I've looked plenty, all of the 40W4100 use 1-876-561-13 (along with a whack of other TVs), but they aren't all interchangeable as that's just the number for the bare board. The number for the assembled board is A-1643-237-A which is only used in the KDL-40W4100's with the panel sticker LTY400HF01/serial number 8200001-8400000. I've yet to find one for sale where either the ad or the seller can confirm that it's the correct board.

That's based on the best info I've found so far, so please correct me if I'm wrong, but I've yet to come across anything confirming that the boards can be interchanged. The only service manual I can find predates my TV so I can't use that to confirm or deny anything either (manual is 4/2008, TV is 11/2008).

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

I tried replacing the board with one I managed to find locally, I couldn't confirm it was an exact match but I figured it was worth a shot. There's still no change (no LEDs, no clicks) I would've guessed it would at least try to turn on even if it was the wrong board but maybe not?

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

I decided to re-measure the voltages going from the PSU to the BU/main board and the T Con to see if anything is out of place to you guys, this is with the standby power jumped to POWER_ON with a 1k resistor and the BU/main board unplugged from all connections:

DIMMER: 2.1V
BACK_LIGHT_ON/OFF: 0V
INV_ERR: 15V
GND: 0V
BALANCER_ERR: 0V

REG12V: 12V
REG12V_GND: 0V
UNREG_15V_GND: 0V
UNREG_15V: 16.2V
STBY3.3V: 3.4V
AC_OFF_DET: 0V

[budm]

Re: Sony KDL40W4100: no signs of life?

You have some bad signals. Training manual CTV-45 Chassis EX1

More service manuals, too big for attachment.
http://elektrotanya.com/?q=showresul...at2=schematics

[CapLeaker]

Re: Sony KDL40W4100: no signs of life?

Jump BLon to STBY, same as you did with PSON and the resistor. Recheck inverr pin.

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

@budm: Following page 38 of the training manual the BU board needs to be replaced. Page 50 goes into the inverter, I haven't got time to check that today but I will this evening. Anything I should be wary of when checking this? According to the manual:

"Check for the presence of 395VDC at CN6600 on the DF1
board. This voltage line is referenced to hot ground so you will have to
read across pins 1 and 3 of the connector. "

@CapLeaker: With BLon and PSon jumped to STBY with resistors, inverr is 1VDC but the backlight doesn't come on. Trying it multiple times I saw 1V, 15V and 3V. I should note that the manual states BLon should get 3.3V from the BU board ~5 seconds after the unit is powered on, however I'm connecting both resistors and then plugging in the unit all at once. I'm not sure if that could cause a problem or not.

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

Woops, looks like I was looking at the wrong page. Pg 43 covers the inverter:

"Once the IP5 board receives a power on high at CN6150-1 the power
supply begins generating the necessary voltages. The PFC circuit
increases the rectified 160VDC to approximately 395VDC to supply
power for the inverter switching transistors. The oscillator provides the
necessary 41KHZ drive for the inverter switching transistors. The inverter
stage outputs approximately 1000VRMS at 2 output lines that are 180
degrees out-of-phase.
Note the inverter detect stage. The detector consists of small-value
capacitors and diodes to detect the AC voltage. If either AC line fails to
output the inverter detect circuits will output a high to CN6154-3. This will
be detected by BE Micro IC3001 on the BU board and the unit will shut
down and blink the standby LED in groups of 6. The event will also be
registered into the diagnostics menu for viewing when entering that mode.
This will be covered in Chapter 7.
The inverter also has over-voltage and over-current detection circuits (not
shown). If either circuit detects a malfunction the oscillator will stop and
create an inverter detect failure"

Looking at the bold part I take it I should see 395VDC at the PFC output when the board is powered on regardless of the inverter error?

[budm]

Re: Sony KDL40W4100: no signs of life?

You should have the PFC Boosted Voltage on the main cap when the PS-ON (Power on signal from the main board to the power supply board), it will drop down if the main board gets an error from the inverter circuit then it will shut down the PS-ON signal, BL-ON signal.
BTW, since you are not even getting any LED error codes on the front panel, then some thing is not right with the main board.

[whyexactly]

Re: Sony KDL40W4100: no signs of life?

I've managed to source a new main board, that's in the mail and should be here soon. I was hoping to verify that PSU is fully functional before it arrives but at this point it's probably best to wait for the main board before proceeding.