Sony KDL-40S504 6 blinks

[budm]

Re: Sony KDL-40S504 6 blinks

I see the LD is connected to R123, the output side of R123 is connected to the Collector of Q101, Q101 Base is driven by IC U1 at the 'OLP' pad. See what DC you get at 'OLP' and alo at 'DET'

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

Tom I put an arrow where that connector is..

Bud I will check that..

I noticed transformer CT101 which is by itself and seems to be part of the error detection, I checked it where the arrow is and if that's the correct spot it shows a short.

That's the same pins I used on the other transformers, although it's a different part..

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

DET is 12.4v when backlight comes on, OLP is 8.4V

[tom66]

Re: Sony KDL-40S504 6 blinks

OLP = Open Lamp Protect.... You may have a bad bulb.

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

Should DET be 12V? Anyway to check without opening the panel or bypass this to check it?

[tom66]

Re: Sony KDL-40S504 6 blinks

Where does DET go? CN6154?

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

Im not sure. If I removed the BALANCER_ERR wire from the PS to main board would that keep it on?

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

Oh what about that transformer I talked about could it be bad and causing the problem?

[tom66]

Re: Sony KDL-40S504 6 blinks

Im not sure. If I removed the BALANCER_ERR wire from the PS to main board would that keep it on?

You'd probably get a 2 seconds to black symptom, but it's worth a shot. Don't run it for too long.

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

That didn't work still got the 6 blinks which seems unlogical to me..

[tom66]

Re: Sony KDL-40S504 6 blinks

"Illogical"...

Anyway, did you check what the error pin measured? Sometimes they naturally float one way or another, and you need to force them.

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

It measured 8.4V and sorry ILLOGICAL... engineers!...

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

OK how bout forcing LD to stay at 12v?

[tom66]

Re: Sony KDL-40S504 6 blinks

That was with the error detect disabled? Try pulling it down with e.g. a 1kohm resistor, on the main board side. (I am assuming you are cutting wire on main board side?)

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

I just removed pin 1 wire out of the CN6154 connector. Ill test the voltage on that with it removed...

[budm]

Re: Sony KDL-40S504 6 blinks

"OLP = Open Lamp Protect.... You may have a bad bulb." I think Tom has the right idea there.

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

Alright let me update, at CN6154.
INV_ERROR is 2.0v until backlight comes on then goes to 0v.
BALANCER_ERR is 0v until backlight comes on, then goes to 8.4v.

I wasn't seeing the 2.0v before perhaps I didn't have a good connection..

[kevinm34232]

Re: Sony KDL-40S504 6 blinks

Something doesn't seem right with this transformer, it doesn't test like the others on the secondary side..

transformer is marked with
086c
c 979f

I don't want to overlook it before opening the panel, this transformer seems like it is part of the error circuit.. It does not test good no matter which way I test it and I can't find a pin layout of it.. This is a Darfon board.

[budm]

Re: Sony KDL-40S504 6 blinks

From the look of the silkscreen designator of CT101, it looks like it is used as Current Transformer. What do you read on the pin? I remember back on one of the post, the poster found one on the socket where one of the finger of the Balancer board goes into has bad socket which is house in the black plastic body, you may want to slide the Balancer board out and see if the fingers and the sockets are clean.

[budm]

Re: Sony KDL-40S504 6 blinks

I check my balancer board which is similar to yours, the two pins with the pointer shows less than 1 Ohm, the two outer pins on the opposite side also shows less than 1 Ohm.
OK, I just trace that out, it is current sensing transformer for all the lamps, its out feed the FB pin. Your transformer looks like it feeds the DET circuit.
So at this point, I believe you have open lamp or lamp did not fire up and stay lit.