dp42740 sanyo green light on/off power fail mode

[lively]

Re: dp42740 sanyo green light on/off power fail mode

well i got the digital main board in Friday and installed it and still the same no 13v on audio everything else i have checked is good on the board i checked c1671witch is the straight line wiring to the audio and it hot but is not on the audio pin point . i am confused because my symptom is a no power issue and i have replace 3 boards totaling 120.00 so far .. power board , digital main board , SS board . and all that should have brought this baby to life . i know how to read a print and diagnose pretty well .. and scotts manuals are pretty in depth straight line wiring diagrams .. bought my boards from shop jimmy.com and i have requested tech support from them since no one cares about these types of threads .. im starting to think im all alone here and all the TV techs that are out there are laughing at me cause its something simple and stupid .... for fuck sakes man !!! help a brother out !!!

[Caleb]

Re: dp42740 sanyo green light on/off power fail mode

There are about 10 full fledged techs active on this site, a bunch of hobbyists and tons of newbs. That said the techs are very busy, the rest of us hobbyists try to help out where we can but our limited experience means that we can be of limited help. So I try to chime in on sets Ive worked on, and easy obvious troubles to free up time for the more difficult ones.

Your set seems to be one of the difficult ones. Is the 13v derived from the 15v supply? Is it regulated on the main board? It could be the 13v is missing in action or it could be that something is dragging down the supply, have you tried it with the speakers unplugged?

[lively]

Re: dp42740 sanyo green light on/off power fail mode

yes i unplugged the speakers 4- pin plug off pwb.board and yes off pin 12,13 15.7v from power board , then goes to audio through L1673/L1674 then to c1671 witch should give me my 13v .. i went through pfail test and found all are good besides audio 13v . thank you for the reply !

[Caleb]

Re: dp42740 sanyo green light on/off power fail mode

Do you have good continuity through those two inductors? They should be less than 1 ohm if they are good.

[lively]

Re: dp42740 sanyo green light on/off power fail mode

I have not tried checking the new board that I just put on there from shop jimmy but the old one I have out they they measure out fine

[zdsh07p9]

Re: dp42740 sanyo green light on/off power fail mode

bump from me, I have the same problem and I replaced the same boards with no results as did lively.

[Caleb]

Re: dp42740 sanyo green light on/off power fail mode

I had a few minutes to look over the board prints for your main board and I found Ic001, also another inductor the 13v appears to travel through. I marked them up on shapshots of the manual for you. the other 4 chip inductors I marked I believe are on the output side of the audio chip but doesn't hurt to check them too. I also marked up a couple resistors and inductors you could test on the feedback circuit. would be easier with a full schematic but we don't have one.

[lively]

Re: dp42740 sanyo green light on/off power fail mode

Ok I have a full schematic off Scott's manuals , that's where I found most of the info . But I will trace it out and report back ! Thanks !

[Caleb]

Re: dp42740 sanyo green light on/off power fail mode

If the schematic is less than 20Mb you can attach it the same way you add pictures, otherwise in pdf viewer you can take snap shot and paste into paint then save and attach.

[lively]

Re: dp42740 sanyo green light on/off power fail mode

ok i have tested (new board) and starting with first pic ie: 1,2,3
on diode setting on my meter


p1-1c001 p-6 = 0.6 ohm

L001/L002/L003/L013= 0.6 OHM

there is no cap above c1671 and the circuit is open point to point

.

2nd pic

off the p24v-15v - R1673 = open no continuity

R1673- L1681= 0.3 ohm but across the diode it is open.


3rd pic


L1676 the first 2 down = (open across no continuity) , but on front side following the line it has continuity

L1675= .01 ohm

L1674= .01 ohm

L1673= .01 ohm

R1683= .440

D1671= .618

..


should i start a return for shop jimmy.com for this new board ? cause i feel like it is bad .. but why ?

[Caleb]

Re: dp42740 sanyo green light on/off power fail mode

All good inductors should have low ohms readings. On the ic001 are you saying pins 1-6 are shorted together? If so that chip cant be good. attached datasheet below- incoming vcc1 for that chip should be on pin 8 measure across C023, vcc2 positive power supply on pin 11 measure across C020- pins 1,2,3 are grounded. If the chip is getting power then the trouble must be in the feedback circuit.

[lively]

Re: dp42740 sanyo green light on/off power fail mode

no p1of speaker plug - p6 of chip

[lively]

Re: dp42740 sanyo green light on/off power fail mode

what pin on chip is supposed to have power?

[lively]

Re: dp42740 sanyo green light on/off power fail mode

pin 8 has 15.6vdc

[Caleb]

Re: dp42740 sanyo green light on/off power fail mode

Ok so chip is not shorted and has power, feedback circuit it is, can you upload that section of the schematic so we can see what is in between that chip an d1761?

[lively]

Re: dp42740 sanyo green light on/off power fail mode

i cannot for the life of me put this straight line big enough to read on here .. i went to toms service manuals and look at page 47-48

[lively]

Re: dp42740 sanyo green light on/off power fail mode

[lively]

Re: dp42740 sanyo green light on/off power fail mode

[lively]

Re: dp42740 sanyo green light on/off power fail mode

[lively]

Re: dp42740 sanyo green light on/off power fail mode

hope that works ?!