I bought a transistor tester of ebay, shipped from china tester pictured below -
The unit turns on and gives me the splash screen + the firmware number.
I have tried several capacitors in the device and they are all "unknown or damaged" the meter is supposed to be able to test ESR. These are brand new out of packet capacitors
I have spoken to the seller and they claim the positioning of components in the test holes is arbitrary.
Does anyone else have one of these? How do you test componenets...
ocf
Senior Member
Last Activity: 03-16-2022, 06:18 AM
Joined: 06-12-2016
Location: England
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Transistor Tester Help
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Re: Samsung - LE32A457C1D - screen artifacts
I've checked the transistor, on my board its marked QT1, I am seeing resistance measurements in the mega ohms between most leads. A couple of readings were in 100's of K
If Q1 was shorted I would see no resistance or very low resistance between two of the leads?
When testing it was exhibiting some strange characteristics, resistance readings not staying steady (possibly due to self ranging DMM) and also same two legs tested twice gave a wildly different reading.
How do these differ from IGBT's,...Last edited by ocf; 09-07-2016, 06:57 AM. -
Re: Samsung - LE32A457C1D - screen artifacts
Packed it in for the night. I will let you know what the results are tomorrow.
If Q1 has been shorted would it be an indicator of a bad panel? I watched a video recently where if a specific TCon transistor was blown it was 75% chance the panel was bad and a new board would go the same way as the old one.Leave a comment:
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Re: TCON Repair Manual - Free PDF
It's actually hosted on the creators website, google links to it, looks like the site is a bit broken. The two PDF's are "part B" of the repair Ebook, part A being the sections that are supposedly sent to you after purchase.
Maybe a mod should remove the links, anyone that wants the PDF's PM me for linkLast edited by ocf; 09-06-2016, 05:05 PM.Leave a comment:
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Re: TCON Repair Manual - Free PDF
Thanks for the tip buddy. I hope he finds this thread...Leave a comment:
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TCON Repair Manual - Free PDF
Found these with a google search whilst looking for schematics,
I've stashed them away in my growing collection of schematics and other reference material, they might also be of use to other badcapers.
Is there a knowledge database I can upload them to?
-OCF... -
Re: Samsung - LE32A457C1D - screen artifacts
[url]http://www.placilcd.ro/images/product/35/320aa05c2lv0-0-1362028164.jpg[/url]Re: Samsung - LE32A457C1D - screen a...8164.jpg[/url]Leave a comment:
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Re: Samsung - LE32A457C1D - screen artifacts
Took of the frame to get access to the tabs, they all look fine and no change to image on screen when I apply pressure.Leave a comment:
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Re: Samsung - LE32A457C1D - screen artifacts
This tv has been worked on before, there are two pieces of electrical tape at base of mainboard, looks the last person put them there to prevent the edges of the boards shorting.
Also the mainboard looks like it has been swapped out possibly an official samsung repair. The mainboard has a label on it. "M.Andi B-Team", I want the A team dealing with my issues thank you very much!Leave a comment:
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Re: Samsung - LE32A457C1D - screen artifacts
Both ways the panel lights but black screen....Leave a comment:
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Re: Samsung - LE32A457C1D - screen artifacts
I could try applying some pressure to the bonds to see if the relieves the image a bit.
Where are the tabs located? I am assuming along the top or bottom of panel, will they be on the same side of the panel where the TCon board is locatedLeave a comment:
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Re: Samsung - LE32A457C1D - screen artifacts
Tried freezing some areas of PCB, no difference. The largest IC is under a EM shield so I will have to remove that to ensure it gets cold properly.Leave a comment:
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Re: Samsung - LE32A457C1D - screen artifacts
I done the opposite and gave the boards a gentle heating with a heatgun. No difference to image after mainboard PCB and Tcon were heated
TCon and Mainboards for this TV are cheap as chips, any way to definitively tell if the panel is bad?Last edited by ocf; 09-06-2016, 11:11 AM.Leave a comment:
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Re: Samsung - LE32A457C1D - screen artifacts
When I say left alone I mean switched on but not pressing buttons or attaching inputs...Leave a comment:
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Samsung - LE32A457C1D - screen artifacts
Hello Badcapers,
This LCD TV turns on without fail but shows coloured lines on screen, see images below.
I have tested voltages from PSU to mainboard and PSU to Inverter, all seem ok.
No bulging caps or other obvious damage.
Reseated all cables and ensured PCB's were secure.
Do Samsung LCD's have a test pattern generator like Plamsmas do? I read that most don't.
If the TV is left alone for a while it settles down and majority of the lines disappear other than a rectangle in center of screen. As soon as I... -
Re: Whats the best temp to reflow SMD components with a hotair station?
The best way to get the feel for a hot air station is to get stuck in and use it.
Temps needed will vary from board to board, depending on its thermal mass. Larger boards can be preheated to bring their ambient temperature up, this means less direct heat to the pad/joint.
A quick google search for lead/lead free solder melting temperature will give you a rough idea of the approx temps you need.
A youtube search for "hot air soldering tutorial" or similar will...Last edited by ocf; 09-03-2016, 12:31 PM.Leave a comment:
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Re: LG Plasma 42PG6010
I was measuring wrong, VS is ok.
I upped the voltages a little, I think there is a slight improvement as it appears the number of"sparkles" towards the top of the screen have reduced but they are still there.
Something to note is they appear worst at the bottom of the screen, this is also where I see the least improvement with the increased voltages. This area of the screen is where I spotted a BBC news banner burned in while running test patterns.
Strangely the burn in only ever showed briefly before the very...Leave a comment:
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Re: LG Plasma 42PG6010
Forgot to say no change in image after VS increase to 191vLeave a comment:
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Re: LG Plasma 42PG6010
I upped the Zbias and VSC voltages, didnt make any difference.
I found the pot for VS but no clear test point, checking voltage across the ceramic cap near the pot gave me 177v, adjusting the pot made the voltage change. Sure enough I found the VS voltage. Its supposed to be 193v. Even with the pot turned up to full I only am seeing 191v across the cap.
Could this be a contributing factor to the mal discharge issue?Leave a comment:
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Re: LG Plasma 42PG6010
different y and Z sus are in it right now, no difference.
I found the ZBias, it was labeled VZ, reading at 100V spot on. There is also a pot next to it.
I need to get the test patterns off and see how the screen looks with different inputs. Might be able to get away with the mal dischargeLeave a comment:
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