APS-254 power supply on a 40" sony

[rammar99]

Re: APS-254 power supply on a 40" sony

Just found this thread while searching for AC OFF DET: http://www.tv-forums.com/forum/TV_Eq...t_all_P154821/

Per that, looks like I should have 3v on that pin. Assuming that's still DC. If so, that's quite a bit different than 0.16v and looks to be the issue.

Will check out your thread suggestions too.

[budm]

Re: APS-254 power supply on a 40" sony

so it does point to the ac off det line.
jts1957, he also posts in badcaps.
ctv-61 az1k Chassis:
https://www.badcaps.net/forum/showth...highlight=AZ1K

[rammar99]

Re: APS-254 power supply on a 40" sony

Pretty much convinced myself that's the issue and have bought a replacement. Should be here next week and I'll post if it was successful. Just wanted to say thanks for all the help yesterday!

[eagle00799]

Re: APS-254 power supply on a 40" sony

I have the same problem, dead set, no lights but I have the APS-284 power supply in my 40" KDL-40BX420. The only voltages I have is the 3.27v stby but no indicator light in front. On the Ac Off Det I get .957v and when I push the power button it drops a bit to .854v . When I unplug the connecter the Ac Off Det goes to 1.94V. I also have 166.v going across the 450v cap with no change when I push power button.
I first thought it was the main board so I replaced it with another used board but no change, Still dead. Any thoughts? I could have gotten another bad main board or it was the power supply all along?

[budm]

Re: APS-254 power supply on a 40" sony

If you look at the diagram for the AC OFF DET [in to be high (close to 3VDC), the LED (pin 1 & 2) on the transmitter side of OPTO ICPH6101 has to be off, so what you can do is to short pin 1 and pin 2 of the ICPH6101 to see if the AC OFF DET pin will go high, or you can remove the OPTO.

[eagle00799]

Re: APS-254 power supply on a 40" sony

I appreciate your input Budm but I'm not sure if your referring to the 4 legged ic that's marked Ac Off Det PH6101, if so I'm not sure which pins are 1 and 2. Or are you referring to the 7 legged ic marked ic6101? Where is this diagram for the Ac Off Det?

[budm]

Re: APS-254 power supply on a 40" sony

Yes, the OPTO IC has 4 legs, per diagram:
https://www.badcaps.net/forum/showpo...52&postcount=4

Per diagram, it has PH6101 designator, the P/N of the OPTO is PS-2561A.
Just look up the spec sheet of PS-2561.

[eagle00799]

Re: APS-254 power supply on a 40" sony

Ok Budm when I short pin 1 and 2 the Ac Off Det pin 2 on the connector goes up to 2.70v, What does this mean?

[budm]

Re: APS-254 power supply on a 40" sony

Ok Budm when I short pin 1 and 2 the Ac Off Det pin 2 on the connector goes up to 2.70v, What does this mean?

It should, so it means the LED inside was on so when you shorted out the LED to turn off the OPTO so the output side of the OPTO swings HIGH toward 3.3V. So if you jumper in place, do you still any error code or does the TV will now startup??

[eagle00799]

Re: APS-254 power supply on a 40" sony

I still have no lights and no start up.

[rammar99]

Re: APS-254 power supply on a 40" sony

Update: got the new / used power supply board in off of eBay and it's working normally. As best I can tell it was in the IC chip on the bottom side of the board that had the failed AC voltage detection. That little chip was going to be tough for me to de-solder / re-solder to just got a board off ebay and it works again.

Thank you for all the help. Great forum. Eagle - if the set is completely dead, my guess would be the power supply. But mine was a different model.

[james28909]

Re: APS-254 power supply on a 40" sony

sorry to dig up this old thread, i am also in the exact same predicament. power coming to psu just fine but absolutely no lights/leds on at all.

here is my finding so far:

standby is 3.3vdc,
ac_off_det is .14v without bridge pin 1 and 2 of ph6101
ac_off_det is 3.3v with bridge pin 1 and 2 of ph6101
pow_on does nothing when power button is pressed with or without pin 1 and 2 bridged on ph6101 and no lights/led show

i have read up on this problem and some people say its the A board, and some say its the psu. can anyone maybe go a little further in depth with me and help me locate the issue? please let me know, i have multimeter and know basics about how to use it and i will be watching this thread like a hawk in hopes someone can help me. thanks in advance for any help. if i can provide any more readings please let me know.

[james28909]

Re: APS-254 power supply on a 40" sony

tv model is 40bx420 with aps-284 psu (g14)

[budm]

Re: APS-254 power supply on a 40" sony

The Ac det should be 3.3V. or more without jumper if the detector circuit, so you do have power supply board problem.
In post 49, we were trying to verify the opto isolation function.

[james28909]

Re: APS-254 power supply on a 40" sony

yes, is a very informative thread. ive got a psu on the way. will post results.
jumping pin 1 and 2 does give 3.3v to ac__off_det but even doing this there is still no lights/leds powered or blinking, and no pwr_on signal while pressing power button... nor any 12-24v to inverter

btw what is ac_off_det mean? ac power off detection?

[budm]

Re: APS-254 power supply on a 40" sony

It detects incoming Voltage level to make sure that the AC Voltage feeding the power supply board is within the AC operating range: the AC is not too high or too low.

[james28909]

Re: APS-254 power supply on a 40" sony

just got in the new psu and hooked it up. was def what the problem was. thanks for the input

[budm]

Re: APS-254 power supply on a 40" sony

Thanks for the follow-up on the repair.
Where did you get the board from? How much?

[Shane711]

Re: APS-254 power supply on a 40" sony

I got this TV yesterday, I have the same symptoms, dead & no blinking power indicator. My Standby is 3.3 vdc and my AC Det is 3+ vdc so I guess that means I have a good power supply and a bad Main. My PS ON does not change when I press power. Main board seems to be completely dead.