Re: Samsung LH50QETELGCXGO
Here is the latest schematic, hope it will help someone....
mmaven806
Member
Last Activity: 01-30-2023, 07:32 AM
Joined: 12-18-2022
Location: Utrecht
-
Re: Samsung LH50QETELGCXGO
Thank you so much, the SM4109 is similar to the one on my main board. I got 4 of mine fixed. Firmware was corrupted. 14 more to go! I ended up copying the firmware from the 2 remaining good display's.Leave a comment:
-
Re: Samsung UN55MU8000 - Backlight But No Picture Problem
KYBOSH,
I tried a pm but it went south. I'll try again later when I'm at the office(desktop).Leave a comment:
-
Re: Samsung UN55MU8000 - Backlight But No Picture Problem
Ok, q211 is good. Pin 4 is the gate, so no problems there.
Q2002, based on your voltages readings, isn't the one I thought it was, so disregard it.
VIN_12V and HVIN_12 are netlabels, so to speak, you won't see them spelled out anywhere, sorry for the confusion.
Now that I have your board on my projector I can make out a Q400 just to the right of AVDD_17V. Is it a "4435"?
If so, ohm between q211 drain and q400 source.
If it doesn't ring good (0 ohm's), then check the fuse...Leave a comment:
-
Re: Samsung UN55MU8000 - Backlight But No Picture Problem
I'll offer an option, if i'm too far off base, someone please set me straight.
Samsung tends to use the same design (ckt), from board to board, that said.
On your main board, ic400 appears to be the pmic, I 'believe' it gets two voltage inputs (main).
One is VIN_12V, it supplies 1.8v, 1.9v and 3.3v (panel).
Second is HVIN_12V, it originates from the VIN_12V, and supplies the havdd, avdd, and vgh.
The two "4435" fets, it believe it was q211 and q2002 on your board supply these voltages...Leave a comment:
-
Re: Samsung UN55MU8000 - Backlight But No Picture Problem
Opps, I meant d410, not d401.
Stupid fingers.Leave a comment:
-
Re: Samsung UN55MU8000 - Backlight But No Picture Problem
Yes, avdd to on left side of d402, little solder ball sitting on top of pad or via.
Vgh is above d401 (top of picture).Leave a comment:
-
Re: Samsung UN55MU8000 - Backlight But No Picture Problem
On the main board, next to D401 is the VGH test point. Should be about +30vdc. Then check AVDD test point next to D402. ( dont short test probe to heatsink).
I dont see VGL (-10vdc) test point. It may be on back side of board.
Hope this helps.
Oh yea, VGL might be labeled VOFF.Leave a comment:
-
Samsung LH50QETELGCXGO
Hi everyone,
This is a display versus television, but same panel and board structure as UN(E)XXTU8000 and QNXXQ60TA's.
First the background, I have several of these with lot more at work that died the same death and from the same cause.
All of them are missing the havdd and avdd voltages.
1.8v, 1.9v, 3.3v, are ok. Backlighting, smps board, sound, processor all seem ok.
I started a schematic, converted to pdf so everyone could see it. I started this past weekend so it is just a beginning, I'm working on the fb_trdy_x traces as I type.
I think this will... -
Re: New Members - please post your introductions here
Well, after reading the above I feel like a new student on my first day of class, but we all learn something new every day, so this is a good thing.
My husband taught me the basics on electricity and electronics and it grew on me. He did it for decades for a large company. I've been learning more and more every week even though I don't work in the industry.
I don't have unlimited access to test equipment anymore but I manage to get by.
I spend my spare time with my kittens that I rescued from a flood...a...Leave a comment:
No activity results to display
Leave a comment: