Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
Final Update,
I ordered a 4.7uF 35V MLCC and replaced C3214. The TV powered back on and is running great!!
I can't thank you all enough for all your help and advice! You all rock!! And thank you for taking the time to instruct me on how to test the different components. I feel like I really learned a few things about testing and diagnosing components (which is something that I really wanted to learn). So thank you all again!
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
Perfect, thank you so much for that. I wasn't sure which of the 2 variables had to be kept the same. and I am replacing a MLCC with another MLCC, but wanted to get one that was rated a little higher so that I could avoid this issue happening again in the future....
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
I have an old PC laptop whose bios chip fried, and a couple of computer monitors whose backlight went out. but I think I am just going to order some new caps.
Should I get caps that are 4.7uF, or should I get higher uF rating?
Should I get caps that are 35V, or should I get higher DCV rating?
Any opinion on the dielectric I should get? (X7R, X5R, etc.)...
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
So I tested the TV WITHOUT the cap in place, and it worked!!!!
As far as what kind of spare caps I have, I don't have any spare caps (I was going to order some. I was thinking I could take a cap from some other device, but I wouldn't know how to tell if the cap I was taking is the same spec as the one I removed from the TV. Is there a way to test for it?...
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
I will test it out on the TV tonight, but before I do, quick question, should I test it on the TV with the cap REMOVED? or wait until I put a new cap on the board?...
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
When testing the resistance between pin 7 and the not-gnd pin of the cap, I get a reading of 1,223 ohm (Tested using the Ohm setting on my DMM) am I using the correct setting on my DMM to test this?...
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
I will take those readings in a little bit, but for now, here are the photos you wanted. Let me know if there are any additional photos you want. (This is how the board currently is - with C3214 removed as I was asked to do earlier in the thread)...
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
Yes I do. So I take 1 test lead and put it on the pad of C3214 and take the other test lead and put it on pin #7 ??
And sorry for such a NOOB question, but should I be using the Ohm setting, the Diode setting, or a different setting to test connectivity?? And I assume the test for connectivity is done while the Main board is NOT receiving power, correct?...
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
Okay, so I connected the Power Board to the Main Board with C3214 removed, and plugged the Power Board into an outlet (I refer to the boards separately from the TV because the TV is at my house and the boards are at my work. I hope that doesn't complicate any ability to test or diagnose)
When I plugged the power board in, there was NO BEEPING! I am not sure if that means the issue is only C3214 or if that was just 1 of a chain of bad components.
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
So I tested C3214 in Ohm mode and measured in both directions, it measured 24 Ohm in both directions
I also tested C3637 in Ohm Mode and with the black lead on the left hand side, I got a reading of 1716 Ohm and when I tried to read it the other way, it went all the way up until the DMM read 1
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
I tested C3637 on the main board, with my DMM on the diode test settings and got a measurement of 245mV. (that was measured with no power connected to the Power Board)
With the power board connected and my DMM on DCV, the schematics you have earlier in this thread show C3637 @ 4.7V and I measured 1.75 (Fluctuating from 1.79 - 1.69) - I had the black test lead attached to one of the bolt holes that mount to the chassis and the red test lead on the same side it was on when I tested the component...
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
Are you referring to which pins on the ribbon cable connector that connects the PSU to the Main Board? and if that is the case, how would I force the the PSU and backlights on with the main board disconnected if I can find the related pins.
Also, where was the short on the main board? do you remember which component was causing the short?
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
YES, a schematic for this exact model power board and main board would be AMAZING!!and if anyone can find one I would be eternally grateful!!
So I am still trying to figure out all the components to test in the All +3.3V circuit. The PDF you attached earlier in the thread, has a Power board schematic that is close, but not the exact model and therefore in the trouble shooting section when it is showing all the components to test in that ALL +3.3V circuit, there are some...
Re: Please Help! My Magnavox 50ME314V/F7 Beeping From Power Board
Sorry it took so long, but I took DCV measurements of each jumper.
Attached is a pdf of the spreadsheet I made that lists the jumper's ID, the jumper's Label, my DMM's reading in DC V, and the ground jumper I used when testing each jumper (I connected the board to power and connected my black test lead to the ground jumper labeled in the spreadsheet and the red test lead to the labeled jumper)
Please let me know if I did this wrong or tested the jumper using the wrong...
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