nashou
Unmoderated Off Topic
Tech in Training.....
Posts: 1,239 
|
Post by nashou on Mar 4, 2017 19:18:59 GMT -5
Nothing, but the 200 volts I had on the one side of D924 is down to about 80 and the other side is about the same. But that might because i do not have the other two connectors in play as I did before.
|
|
|
|
Post by mastertech on Mar 4, 2017 19:44:52 GMT -5
Well this could end up being very difficult to trouble shoot. Very complex. But we could also get lucky and find it quickly. What do you want to do? You may have to spend some time with it.
|
|
nashou
Unmoderated Off Topic
Tech in Training.....
Posts: 1,239
|
Post by nashou on Mar 4, 2017 20:02:05 GMT -5
Well this could end up being very difficult to trouble shoot. Very complex. But we could also get lucky and find it quickly. What do you want to do? You may have to spend some time with it. I guess we could keep going , why not. If its a lost cause after a few days then i'll tell my buddy its not worth it. Nashou |
|
|
|
Post by mastertech on Mar 4, 2017 20:12:58 GMT -5
Well just an FYI, there is a PS on ebay for 50 bucks. Sometimes it is easier and cheaper to just get used boards then putting parts and time in trying to fix. That is why I do not work on TV's anymore.
|
|
nashou
Unmoderated Off Topic
Tech in Training.....
Posts: 1,239
|
Post by nashou on Mar 4, 2017 20:19:17 GMT -5
Not my TV so I cont go buy a supply.
But lets see what we can find. Might get lucky.
If you think its not worth it then we can ditch it.
I'd have to find out from my friend if his friend is willing to try the new PS unit.
But I doubt it.
Nashou
|
|
|
|
Post by mastertech on Mar 4, 2017 20:38:40 GMT -5
Ok. Plus there could be a problem with more then 1 board. I will look into this further tomorrow. Don't have time tonight. And I am sure you want to soak your back.
|
|
|
|
Post by mastertech on Mar 5, 2017 21:26:26 GMT -5
I did a little checking and as I suspected, the first thing that needs to be done is recap the PS.
|
|
nashou
Unmoderated Off Topic
Tech in Training.....
Posts: 1,239
|
Post by nashou on Mar 6, 2017 8:15:59 GMT -5
I did a little checking and as I suspected, the first thing that needs to be done is recap the PS. Even the film Caps? I was going to do that since that main filter cap was bulging and read 2.2nf vs 220uf . The Sm trouble shooting section shows that it should have 400 volts on the rectifier. I am not getting that, is that dependant on the PS being able to "turn on" via the main power switch ? Nashou |
|
|
|
Post by mastertech on Mar 6, 2017 10:55:14 GMT -5
Where are you testing for that 400v and what do you have?
|
|
nashou
Unmoderated Off Topic
Tech in Training.....
Posts: 1,239
|
Post by nashou on Mar 6, 2017 11:36:16 GMT -5
Where are you testing for that 400v and what do you have? BD901. I was following the trouble shooting guide on page 33 of the service manual . "
Is BD901 (+320V) output? (Set the main power SW to OFF.) * When power on/off switch is on ‧‧‧ About +400V"But it says it should read that with power switch on, but that does noting so not sure if me testing it there has any point till it fires up. I think i had -72 on the neg pin and 80 on pos pin. At work now so I'll have to check back later. I was then going to look at all the components they say to check : "Does the PFC circuit operate normally?
(L903, L964, Q925, ZD914, D930, Q902, IC902 and etc.
And, the circuit around the protection circuit etc. is checked.)"
But I can not find Q902? maybe its a miss print ? Nashou |
|
|
|
Post by mastertech on Mar 6, 2017 12:48:28 GMT -5
BD901 is not a pos/neg device. You need to test across it. Neg probe on pin 4 and pos probe on pin 1. If you were not using hot ground you were not getting a proper reading.
|
|
nashou
Unmoderated Off Topic
Tech in Training.....
Posts: 1,239
|
Post by nashou on Mar 6, 2017 17:34:14 GMT -5
BD901 is not a pos/neg device. You need to test across it. Neg probe on pin 4 and pos probe on pin 1. If you were not using hot ground you were not getting a proper reading. Ok I had 169 , So I did some investigation. First I found a short on Q902 , not sure as it was in circuit so I also tested the resistors R924,926 and both were bad OL. The Schematics say .12 oh 1 watt, but the parts say .18 ohm. I am sure it doesn't matter. Q902 also measured bad on my tester, it was measuring as a resistor .   |
|
nashou
Unmoderated Off Topic
Tech in Training.....
Posts: 1,239
|
Post by nashou on Mar 6, 2017 19:17:09 GMT -5
Also ZD914 The Parts list has BZX84-C20 but the Schematic has BZX84-C18
One is a 20 volt the other an 18 ? Which do I go with? seems its like this on everything with this board . The cap I changed was also different on board than in parts list and Schematic.
EDIT: Decided to go with the parts list since the resistor was listed the same as on the board, .18 ohm 1 watt
Nashou
|
|
|
|
Post by mastertech on Mar 6, 2017 19:41:10 GMT -5
You're doing fine. Let me know if you have any questions or need assistance. You might want to check all those TVR's. Lift 1 leg and make sure they test open, I believe.
|
|
nashou
Unmoderated Off Topic
Tech in Training.....
Posts: 1,239
|
Post by nashou on Mar 6, 2017 19:55:29 GMT -5
You're doing fine. Let me know if you have any questions or need assistance. You might want to check all those TVR's. Lift 1 leg and make sure they test open, I believe. I was going to ask about those Like RV902 for example. I did pull those and they measured on my tester like a capacitor? What are those? Nashou |
|
