Re: Telefunken d48u300n4cw with sound and picture but no backlight
It's working now! Only thing is that there is a loud buzzing sound when I'm using specific picture presets or at low backlight settings, but It will do for now.
Thank you so much for your help, dick_barton! I wouldn't have found the issue on my own....
vigorcent
Member
Last Activity: 10-11-2021, 11:33 AM
Joined: 07-26-2021
Location: Aachen
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
I will try to move this component and will let you know tomorrow.
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
Well now this is really strange... I didn't see that, thanks for pointing that out.
No, it is not a burned component, but there initially was one. This is the power supply I bought from the replacement store. In fact, the component wasn't removed, but moved to the left. I'll post a picture for comparison.
On the left is my old psu that was originally built into the newly bought TV. This psu didn't show the initial backlight flash (and voltage peak at led pins) when turning on the TV.
...Last edited by vigorcent; 08-18-2021, 07:21 AM.Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
None of them seem to be present. I just tried to look for a schematic for my specific model again, but I can't find anything....Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
Quick update: Pin 15 and 16 of MP3394 are 11.6V and 5.9V
Sorry for the dumb question, but how exactly do I check q510 and q511 (picture below)?Last edited by vigorcent; 08-18-2021, 06:31 AM.Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
I measured C534, as well as C104 and C105 the other day. They were at 388V (sorry forgot to mention that I already checked that).
I will check MP3394, Q510 and Q511 when I'm at home later. The thing is a that I bought this new psu just a few days ago. So considering that they didn't sell me a defective one, it should be alright.
So my best guess would be (like you said, too) that there is something wrong with the leds, but they all looked fine to me yesterday.Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
So, as you said: BL_ON-OFF voltage is present, but how do I know how much voltage I actually need and if the 3.2V I get are ok? I can't really deduce it from the schematics.Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
Ok, I just checked them again and everything seems fine. Since I'm by far no professional, I'll describe what I did and maybe you can tell me if I did something wrong.
First of all, there are two separate groups. Each group consists of 2x11 leds and 1x12 leds. Each strip is also separated into sub strips (left and right).
The wires are as follows:
First group: red = led+ / orange = led-
Second group: brow = led+ / black = led-
1. I checked continuity between each...Last edited by vigorcent; 08-17-2021, 01:11 PM.Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
Ok, I will check them again later and let you know. How do I check the connection exactly? Just looking for continuity at the connectors between the strips?...Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
No problem, I still appreciate that you're helping me.
So I do have two PSU right now. When using the old one, there is no backlight flash anymore, so the voltage doesn't peak like you said and only stays roughly at 80V for the red and brown wires and at around 8V for orange and 4V for black.
When using the new PSU, there is a flash and the voltage peaks at this value -> and then slowly drop to this voltage (takes about 20 seconds if I remember correctly):
orange: 60V ->...Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
That's exactly where Q212 would be. I actually tried to find this location the other day....Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
Yes, they are fuses and they seem to be ok (0 Ohm on both of them). I posted a screenshot where they are located in the schematic on page 66 (FS1 and FS2).
I'm not sure if the PSU schematic I posted above is consistent with my 23253538 model. Because pin 9 seems not to be connected to anything on the PSU. It only leads to this J57 bridge (see pictures), which is not connected....Leave a comment:
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Re: Telefunken d48u300n4cw with sound and picture but no backlight
First of all, thanks for helping me!
So I just tested the voltages and they show:
1) 11.5V
2) 0.8V
3) 5.4V
4) 5.4V
5) 0V
6) 5.1V
7) 10.3V
8) 11.8V
Also, thanks for posting the link to the manual.Leave a comment:
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Telefunken d48u300n4cw with sound and picture but no backlight
Hey there everyone,
so I was trying to repair my grandpas TV, but I came to my limits. I only have basic knowledge and
I'm still a novice, but it actually was kind of fun and I learned a lot this far.
As this forum helped me already, I finally decided to make my own thread and I hope someone of you can help me here.
So first, the models are:
TV: Telefunken d48u300n4cw
PSU: Vestel 17ips20-r9 23253538
Mainboard: Vestel 17mb100
I don't really know which number on the mb is relevant for further specification, so I will attach... -
Re: New Members - please post your introductions here
Hey there,
I'm new to this. I do have some basic understanding of electronics, but I'm still a novice. I tried to repair my grandpas TV and I can't find the culprit. As some posts here helped me already, I finally created an account to make a thread myself.
Unfortunately, my grandpa passed away recently, so even if I succeed, I cannot show him anymore. I still want to repair his TV if I can, though. Kind of to fulfill his wish.Leave a comment:
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