New Power Supply and Main board Still No Power

[Exp0]

Hello everyone i believe i am going to pull my hair out. I recently repaired a TV that my brother gave to me simply by replacing the caps. After i sold the TV i felt confident that this whole electronic repair thing is easy (WRONG). So i acquired a Sony KDL 40EX600 from a guy off of craiglist. He said that it simply wouldn't power up one day. No LED s just the lonely sound of a relay clicking once.

So i dive into it and all the caps check good (i removed them all) on the power supply. i Then researched how to check other components and after a couple of days of tinkering i decided it would be best to just replace the power supply. Still no LED/ No power, although the new power supply relay didn't click. (I got the power supply from Wisiny.com)
I didn't want to mess with the main board just because I feel like it is out of my league. So I Replaced it. (Shop Jimmy .com )

After replacing both boards I still Have Zero power. Does anyone know of anything else that I could look into?


I have listed the DCV that I am reading from the power supply below. (Refer to Image 377)

Black wire pin 1= 3.30v
brown wire pin 2=0.88v
red wire pin 3=0.00v
Orange wire pin 4=0.00v
yellow pin 5=0.00v
green pin 6=0.00v
blue pin 7-0.00v
dark blue pin 8=0.00v
grey pin 9=0.00v
black pin 10=3.30v
brown pin 11=0.00v
red pin 12=0.00
SPACE at Pin 13
White pin 14=0.00v
Yellow pin 15=0.00v

My wife is starting to doubt me and she loaned me the money to get into this endeavor so my man hood is on the line here.

PLEASE HELP!

[Hamie]

Re: New Power Supply and Main board Still No Power

you can't have 'zero power' because you have standby voltages.

Put your probe on the PS-ON pin, try turning the TV on, does it get any voltage?
If it doesn't then it looks like it's not getting the signal to turn on from the main board.

If so try jumping the back lights on by connecting ps-on to stby, and also stby to bl-on.

Also note if you buy form ebay it doesn't mean it will work or has been tested regardless of what the seller says.

[Ltank]

Re: New Power Supply and Main board Still No Power

When checking secondary votages use chasing ground, for the
24,12,5, or 3.3 vdc.

[johnboy1313]

Re: New Power Supply and Main board Still No Power

I have bought three boards from ShopJimmy. Two of the three were dead out of the box. One of the two dead boards was replaced with a dead board. I had to go through hoops with the tech on the phone to prove I knew enough about what I was talking about to get them to send me a third board for that one. As far as I'm concerned it's not only possible that you got a dud board from ShopJimmy, it's probable.

[Exp0]

Re: New Power Supply and Main board Still No Power

Hey everyone thanks for the help sadly I have no good news.

Hamie

PS on =0.00v
Jumped Stby 3.3 to Power.on (pin 1 to Pin 3)= Relay clicked about it.
Then i also jumped stby to BL On (pin 1 to Pin 12)= No results except for a very faint humming sound that sounded like it was coming from either the main board or the right side of the TV. It went away before i could track it down and i couldn't replicate it. I didn't see any burns or bad smells though. Please see the attached photo.

I hope this doesn't mean my Screen is Fried.

Ltank

I'm sorry but my electrical knowledge is not that strong. What is a chasing ground? Are you talking about grounding my self so that i don't end up as toast?

Johnboy1313

I believe that if i have to talk a tech guy into believing i am right and he is wrong i will lose that battle.

The extent of my electrical knowledge comes from schooling in Fire and Explosion Investigation. I'm def no Electrical Engineer here but i know enough to kill myself.

[budm]

Re: New Power Supply and Main board Still No Power

You put the jumper on the wrong location, you have it on the Dimmer pin 12, it should be on the BL-ON is pin 11.
It is not a good idea to jump the STBY power and the pin without removing the wire going back to the main board, if there is no buffer resistor on the main board and it is connected directly to the Collector of the switched Transistor that is fully on, you can damage the Transistor. Always use resistor to limit the current in case you put the connection at the wrong location and wipe out your standby power supply.
15 pins connector with 15 pin names.

[Exp0]

Re: New Power Supply and Main board Still No Power

BudM
Hey I see what your saying about the correct pins. So i tried it again with the main board disconnected this time using Pin 1 Pin 3 and Pin 11. No Back lights. I darkened the room to see if the room light was drowning the light out. See attache photo. I made sure none of the alligator clips were touching any other pins.

[usermike9]

Re: New Power Supply and Main board Still No Power

I have replace 2 of these main boards in the past . I also agree with johnboy1313 about defective replacement parts. ShopJimmy has dropped in what I reliability. They will usually take a return but that is not to say you will not get another dud.
I kind of skimmed over what you have posted above and it sounds like your PS is working. Forcing BL on will confirm this but has nothing to do with the underlying issue.
You stated above that you had 0.0 on the PS-ON pin when pressing the power button. This indicates no signal from the MPU = Main board bad.

Not what you want to do but I would get another Main board from another source preferably a smaller shop where you can talk to a tech and feel comfortable that it was "TESTED" I also agree with Hammie about eBay seller claims. Not all but way to many just claim they are working parts so buying there could be out of the frying pan and in to the fire.

[budm]

Re: New Power Supply and Main board Still No Power

OK, lets find out if the PFC Voltage booster circuit is working or not first since the rest of the power supply sections need this boosted Voltage.
Check the DCV between the two legs of the main filter cap to see if it has >360VDC with force on in place.

[Exp0]

Re: New Power Supply and Main board Still No Power

Budm
So I plugged in the power and checked the main filter cap ( 450V 150uF), I got a reading of 166 DCV. I still have my old power supply should I see what that one reads as well? I attached a picture of an over view of the PS so what you can see what we are working with here.

Usermike9
I'm going to see if i can return my main board, but in the mean time ill be looking for a new one from a different supplier do you have any suggestions.

Is the reading of 0.0v at the ps on pin justifiable enough for the main board being bad or do i need some more evidence?

Sorry it took me so long to respond my boss has been up my rectum lately.

[vicvc]

Re: New Power Supply and Main board Still No Power

d6204 d6205 next to t6201. if either of these test low resistance, smd chip at bottom gone and ps no good

[budm]

Re: New Power Supply and Main board Still No Power

Budm
So I plugged in the power and checked the main filter cap ( 450V 150uF), I got a reading of 166 DCV. I still have my old power supply should I see what that one reads as well? I attached a picture of an over view of the PS so what you can see what we are working with here.

Usermike9
I'm going to see if i can return my main board, but in the mean time ill be looking for a new one from a different supplier do you have any suggestions.

Is the reading of 0.0v at the ps on pin justifiable enough for the main board being bad or do i need some more evidence?

Sorry it took me so long to respond my boss has been up my rectum lately.

PS-ON signal is generated by the main board when power switch is activated, <1V = Off, >2.5V =ON.
No PS-ON = No PFC boosted Voltage, and other section of the power supply will not be on.

[Exp0]

Re: New Power Supply and Main board Still No Power

Vic VC

My MM in diode mode ( Veyron VL-890D)

D6205 Reads 442, Nothing when neg and pos are switched

D6204 Reads 435, when Neg and positive are switched = 1449 I had a similar diode that had the same reading. I thought it to be bad so ordered a new one. When i tested the new diode I got about the same reading.

PS. I tested both of these in circuit. If I should take them out let me know.


BudM

If i am understanding you correctly the Primary Filter Cap (PFC?) is not producing the rated 450DCV because the Main Board is not telling the PS to provide the Power. There by proving that the main board is defective. Am i correct?


Thanks for all the help you guys are giving me!

[budm]

Re: New Power Supply and Main board Still No Power

If there is no DCV at the PS-ON pin on the power supply board, that means the main board is not working or something lock out the board from sending the PS-ON signal.
You can remove the wire going back to the main board first and then use 330~1K Ohms resistor between the PS-ON pin and the Standby Voltage of the power supply pin to force on the power supply board, then you should see the DCV on the filter cap jumps up from 160VDC to >360VDC.

[Exp0]

Re: New Power Supply and Main board Still No Power

Connecting Stand By and Power on i get a reading of 167VDC at the PFC.

[budm]

Re: New Power Supply and Main board Still No Power

Well, PFC booster is not working.

[Exp0]

Re: New Power Supply and Main board Still No Power

I'm going to try the same test on my other PS board once the little goes to bed.

[steviewonder]

Re: New Power Supply and Main board Still No Power

just a little thought,provided the 5v supply is fine,surely the standby light would come on,regardless of a possible pfc fault?,i would lean to a duff mainboard.I'm not keen on modern-ish sony's.nothing is ever easy with them....good luck though!

[budm]

Re: New Power Supply and Main board Still No Power

just a little thought,provided the 5v supply is fine,surely the standby light would come on,regardless of a possible pfc fault?,i would lean to a duff mainboard.I'm not keen on modern-ish sony's.nothing is ever easy with them....good luck though!

We know that there is problem with the main board because it does not put out PS-ON signal, right now we are also trying to find out if the power supply boards, new and old, are bad or not also.

[Exp0]

Re: New Power Supply and Main board Still No Power

Old power supply with a jumper (I don't have a 330~1K Ohms resistor, new to the game) between Stand by and PS ON 166VDC.