Capacitorial
Member
Last Activity: 02-09-2025, 03:44 AM
Joined: 12-21-2019
Location: Baden-Württemberg
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Could it be the transformer on the PSU? I had one CCFL TFT that had a bad transforer that was way too damaged to function properly and the monitor backlight went off after a few seconds. The transformer was sqeeking too. -
Hello [USER="28070"]www[/USER] and [USER="332946"]Vectrex[/USER]
If the backlight is CCFL technology, there must be a transformer on the board somewhere, that is transforming the voltage for them.
I had a monitor like that that did the same thing. The reason was that some windings were burnt.
Sometimes you can hear a very high pitched noise or whining from these inverters when they are faulty. Sometimes they get very hot.
This picture shows how it could look like. They can look different in your case. The fault will probably be only visible from the...Leave a comment:
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Powersupply has all the voltages - Monitor still no power
Hello guys,
I have a Philips 240B7QPJEB. The monitor seems completely dead.
I opened it and measured the voltages of the powersupply. I found that a mosfet was dead and replaced it.
On the connector, that goes to the TCON board, all voltages 15-19V and 5V are present.
The small connector on the left of the PSU has two cables with 18V and all the other have 0.2V. It connects on this small connector on the left ontop of the panel. I guess the backlight? Seens fine I guess.
The weird thing is, that the Power LED is powered over the TCON board.
On The TCON... -
Good beginner repair projects?
Hello!
I learned a lot the last weeks about repairing and how power supplies are structured. Fixed two TVs (even though it wasnt really hard since one was a backlight and the other a ribbon tape trick fix).
Let's say I got a basis of knowledge from where I can start to repair easy projects.
Looking on local online markets, there are sometimes faulty devices for free. But where to start?
I try to stay away from notebooks and mobile devices. I don't believe I got the experience, even though it feels like I could do something, after watching hours of notebook... -
No, short was still there....Leave a comment:
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It is only connected to the TCON Board via ribbon cable. I disconnected the TCON board and the described shorts are still occuring. This time I used the ground of the board, not the TV chassi. So this means we can rule out the TCON board. The fault has to be on the buffer strip or the panelLeave a comment:
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Yes you are right, if I check with continuity mode the capacitor and the test-point LSD, it is beeping.
What makes me sceptical though, is that when I desoldered the capacitor and checked it with continuity mode, it did not beep.
Does this mean that the short is not the capacitor, but something AFTER the testpoint/capacitor? How can I check this?...Leave a comment:
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Hello [USER="169795"]lotas[/USER] I measured the resistances you told me to check.
These 5.0-5.8MOhms resistances start rising to around 6 and go a little higher from there.
I don't really know what resistances to expect here, so I hope you guys can help me on that.
[USER="75051"]Diah[/USER], the cap you mentioned does not lead to that contact you marked. I checked with continuity mode and there was no connection. Actually, there is no component that connects to that point. I will skip this step for now, since there is no return after cutting it...Leave a comment:
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Since I know now that the CL1 capacitor is not short by itself (since I desoldered and tested it), how can I find where the short is? There are no tracks that I can follow. I turned the TV on without that capacitor and the fault was still there.Leave a comment:
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Hello [USER="71977"]nomoresonys[/USER] , this is the capacitor I was referring to. I cannot trace it to anywhere. The only thing I know is it belongs to CL1 which from what I have seen in videos can be a reason for this fault. The question is, how do I know how many µF it has to replace it?
EDIT:
I made a mistake. I desoldered the capacitor. It does not seem to be shorted. Doesn't beep on any side... The search goes on.
If I make the continuity check on the PCB where it was (on the pads of CL1), it still reads a short to ground. What does that mean?nomoresonys...Last edited by Capacitorial; 12-28-2023, 06:08 AM.Leave a comment:
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So I couldn't really find anything else. It seems that all the voltages are ok and since the TV is basically playing normally except for the sometimes flashing artefacts and lines, I guess it is a fault outside of the PSU.
The only thing I found was a ceramic capacitor on one of the panel buffer boards right under the panel, that was shorted. It beeped on both sides while all other capacitors didn't.
Is there a way to learn about those boards? I would like to better understand what they do and if a capacitor could be the problem for this faulty picture.Leave a comment:
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So, I guess this might be a dead end since I found other sources with the same and similar problem. This diode PROBABLY is a TVS diode. That is why when testing it in or out of the pcb, it will give different results.
I soldered the diode back in and will go on from here to check the ribbon cables that go from the TCON board to the screen.Leave a comment:
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Philips 46PFL8007K/12 - Picuture flickers on half of the screen
Hello guys.
I recently got a TV that has the following problems:[LIST=1][*]Sometimes it has to be turned on and off a few times, to boot up. Sometimes it starts from the first try[*]When it is running normally, the right side of the screen flickers. Sometimes it is just a square of transparent white maybe a 1/3 of the right half (top right)[*]The flicker is also sometimes a square that is filled with lines[*]I noticed that when the TV brightness is set to max, it flickers less. I think the Standard setting is the worst where it comes more frequent[*]When it runs a few minutes it gets...Last edited by Capacitorial; 12-17-2023, 11:18 AM. -
Re: Korg Vocal Sample
So I found out that the parts and schematics are similar to the ones from another model of synthesizer.
Schematics: [url]https://cdn.badcaps-static.com/pdfs/a5e824e9bf3f49d5199ccbae6a5f9a79.pdf[/url]Re: Korg Vocal Sample<br /> <br /> ...9a79.pdf[/url]Leave a comment:
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Re: Korg Vocal Smample
SW - PGND: 2.4 Ohm
SW - GND: 2.4 Ohm
Is it because if it is shorted than basically VIN is shorted to GND? I am a beginner with ICsLeave a comment:
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Re: Korg Vocal Smample
Hello budm!
Pin 8 is connected to Pin 2, and Pin 1 (PGND).
VIN - SW : 3.3 Ohm
VIN-PGND : 3.3 Ohm
VIN - GND : 0.1 OhmLeave a comment:
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Re: Korg Vocal Smample
You are right. Could you assist me on finding the right ones?
[url]https://imgur.com/a/9CbLJ79[/url]
This is the example from the datasheet. I see three caps in proximity of the chip. On the datasheet example are not that many.Re: Korg Vocal Smample<br /> <br />...not that many.Re: Korg VocalLeave a comment:
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Re: Korg Vocal Smample
How can I find out the values of these caps? If they happen to be dead, I need to find a replacement.Leave a comment:
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Re: Korg Vocal Smample
Hi stj, thanks for your reply.
The upper pin where the 9.75 V are on, has no resistance to ground. After the fuse (lower pin on the picture) has 200 Ohms. (Settings on my DMM are Ohms 2k and display showing 0.222)
EDIT:
I searched for the datasheet of the voltage regulator on the picture. It is a TPS6211. Pinout of the chip: [url]https://imgur.com/a/JiCuc1a[/url]
the pins 1 and 2 (VIN) are shorted to ground. Both pins go to a common smd capacitor. I guess the chip is dead?Re: Korg Vocal Smample
HiLast edited by Capacitorial; 05-02-2020, 09:48 AM.Leave a comment:
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