Re: Half dozen psu repair challenge
No, it wouldn't.
No, it wouldn't.
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Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search. -
Re: Half dozen psu repair challenge
Sadly I had no time for repairs during weekend since I wasn't at home. Also I took apart my old isolation transformer setup kludged together from two old tv trafos. I want to do the cabling and some sort of housing for this brown-green hulk. I'll continue soon.
I got some other bad psus too. One has a centipede on the primary side...Attached FilesComment
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Re: Half dozen psu repair challenge
So I got into it and fixed the two smaller fortons. It wasn't too hard. Most of the Capxon caps on the secondary had to go, supervisors are ok. Voltages are back to normal. Sadly the Epsilon's ps223 seems faulty. Also I modded a forton gln psu to test the supervisor cards a bit faster.
In the Macron I discovered a resistor wrapped in a toasted crunchy heat shrink. It's between the primary trafos two legs. Color code tells me it's 15 ohm but it measures 17.
The chieftec CTG-450 is kind of strange. Isn't the primary 180uF cap a bit small for 450 Watt?
It had a lot of cold solder joints and the 12V filter caps measured twice the original capacity!
It runs now, but the fan spins on max all the time. I checked the thermistor, two transistors, zeners, resistors... tried putting 4.7, 10, 20 Kohm resistor in paralell with the ntc but still no use.
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good night! I have this screen that looks half black and half white. the tcon gives a low vgh value (5-6v). the rest seem fine. I first removed the flex from one half of the panel and then the other. Removing the left, vgh increases it to 25-26v. I think the problem is in that area, but there are not many elements on the integrated controller board. there are no shorted capacitors. could they be a cof? Some help?
By the way, now the entire screen is black. Maybe some flex was not connected correctly... I have exchanged the flex and there are no variations, I don't think they are the... -
I found another post on this site the other day which has been very helpful in troubleshooting this issue I am having with my tv. The left half of the screen is dark, and the other half is VERY slow to generate it's image - and it only generates part of its image at that.
Based on this yt video, I have narrowed it down to an issue (short?) on the left side of the display, somewhere in the system of ribbon cables.
when I remove the bezel and the rear cover, I can get the image to display correctly by manipulating the ribbon cables on the left side which connects the left lower display... -
The 55" LG has been in the basement for a few months without being used. Turned it on yesterday, set came on as it should and showed a complete screen for about 5 seconds (was on a broadcast channel but no antenna was connected), then the screen went mostly dark with about 1/3 of the screen on the right lighting up with brighter lines in that lit part (sorry, no pictures of that). Power LED was cycling too, preventing the TV from fully powering up.
Pulled the back off, all boards looked OK. Pulled the LED connector, turned the set on to see if it would power up but I don't belive it... -
Hi,
I have a MSI Optix MPG27CQ screen to fix, only half screen is working, I found a burned chip on the right buffer board (S270DP01V00_HF_SR) but I can't read the model. Can anybody help?...04-08-2025, 05:53 AM -
Hello everyone, I'm trying to fix what seems to be a half-bridge smps.
The switching controller is sg2525a, which I have replaced with a brand new sg3525a. The low and high mosfets are 1c27ac 6n50. The mosfet driver is IRS2301S.
Both mosfets were tested outside circuit with a component tester and seem to be fine.
With oscilloscope I see ~65khz switching signal on both low and high outputs of the controller, but on the output of the mosfet driver there is switchig signal only on the low output (flat line on the high output).
So I guess the mosfet driver is faulty?
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