Re: Proscan 42LA45H PSU Problem
Would there be any possible issues if I shorted the in pin (5v) of that MOSFET to the out pin on the MOSFET? I accidentally did it before and the led lit up like the board was good to go. Just doing this to see if the set would actually turn on. Don't wanna burn something up tho.
Nr1Ctr
Member
Last Activity: 10-18-2015, 06:57 AM
Joined: 10-14-2015
Location: Columbia, MD
-
Re: Proscan 42LA45H PSU Problem
I have to run some errands, but I will be back later tonight and we can go from there. I'll take a look and see if I can puzzle anything out as well. Would help if I understood how it worksLeave a comment:
-
Re: Proscan 42LA45H PSU Problem
Those data sheets are Greek to me man, lol. They appear to be the right parts, but that's all I can sayLeave a comment:
-
Re: Proscan 42LA45H PSU Problem
Yeah, I took pics and posted them (#19) earlier. But I'm definitely getting a bunch of voltage on the hot side of that OPTO and little to none on the other side of it.Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Ok, when I measure the hot side of the OPTO like you described its reading ~9.8VDC when I push the power button and when I leave it alone.
I don't know the history. Just found it out by the dumpster and had hopes of fixing it on the cheap. Screen and everything looks pristine and I can't see anything visually wrong with the main board. I have not removed it and looked at the back of the main board, however.Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Ok, I didn't really understand what you said there but I got the gist of what you needed from me I think. I tested voltages at V816 and results are in the pic. Might as well be 0vdc on both sides. I also tested voltages at N805. I didn't know what pins were 1 and 2 so I measured them all. The two pins on the cold side read fine and results are in the pic. The two pins I tried to measure on the hot side must be VAC not VDC because my little meter went all wonky when I tried to get the voltages off those ones.
I tried all of these voltages...Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
When I pushed the power switch the values did not change at allLeave a comment:
-
Re: Proscan 42LA45H PSU Problem
Yeah, the reading on the out pin was < 3vdc and the in pin was 5vdc. It was not with the supply only. I just plugged it back in to the TV like it should have been and tested the voltages at the pins coming out of the components. I didn't toggle the switch at that time, but I just did and got the same readings.
On a side note, while checking the voltages I accidentally shorted the in to the out on the m5v relay and the LED light at the bottom of the board came on. I guess that means that the relay isn't getting the signal it needs to...Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Nevermind, I'm retarded apparently. Thought I had to measure the voltages from the bottom of the board and realized that I could do it from the top. Have attached the pic with the measured voltages. I could not reach VCC2 from the top, but there was a bare wire on top (W808) going to it that read 0.26v....Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Does it just need the AC power hooked up or do I have to make sure all the ribbon cables are connected?Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Here are pics of the two in question. Will get back to you about the voltage soon as I figure out how to get it without zapping myself....Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Ok. I will have to figure out how I can hook it up to power and still get access to the back of the board. Will let you know what I find. Thanks again!Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Are these good or do I need to get clearer ones?Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Here's the better pics. I took 4 instead of 3 going across from left to right. And a zoom in of the box you outlined. Hope you can get better visualization. My camera was having a hard time focusing but with more light it gave the glare again....Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Ok. Will get em first thing in the morning. I can email you the pic from my phone if you want. It's much higher quality and a lot easier to see the traces.Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Back now. I like assembly. Only problem is that for every line you write in C++ you have to write 10 (or 100) in assembly. Will be here for a few hours now if anyone has some idea of where I should go from here.Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
Alright then. Back in a bit. Test time..Leave a comment:
-
Re: Proscan 42LA45H PSU Problem
More pictures as requested. It'll be a couple hours before I'm back on here. Taking an Assembly Language class (one among many) and I've got a test today. I'll try and check on my phone. Thanks again
Took me 30 minutes to upload the pics, lol. Hope you don't need many more....Leave a comment:
-
Proscan 42LA45H PSU Problem
Hello all!
I've got a Proscan 42LA45H LCD flatscreen that has PSU issues that I'm trying to fix. I looked at the other posts related to this TV and particular board but the problem I'm having seem different. The unit has standby power but will not turn on. This first thing I checked, thanks to you all and others on google, was the caps. I found one that was obviously bad and changed it out. The others looks fine, but I have no way to test them as all I have is a cheap DVM.
There is also a humming noise coming from the PSU board after I plug it in, and I'm not... -
Re: New Members - please post your introductions here
Hey all!
My name is Justin and I'm here for help troubleshooting a PSU for a Proscan TV I acquired. If I can fix it, its gonna save me a ton of money for Christmas this year.
I don't have a big background in electronics but I can fix just about anything else. Would be nice to learn this skill as well.
Looking forward to talking to all of you.
/RLeave a comment:
No activity results to display
Leave a comment: