Re: iMac 24 PSU LITEON PA-3241-02A1 250W
I connected pins 1 and 4 with a 1k resistor. Now the output is as follows:
pins 2, 8, 9, 10 give 12.25V. Others all 0
over pin 1 and 4 is 0.5V. No display or motherboard was connected.
I think this is ok and will mean something in the start circuit is defective or the condensator is defective and gives too low energy for starting up?
(with motherboard and LCD connected before the following things happened: diagnostic led 1 was on and stayed on,
leds 2 and 3 come on, the...
koektrommeltje
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Last Activity: 03-11-2017, 08:56 PM
Joined: 03-15-2009
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
To come back on my defective power supply:
according to the post 67 of "Toasty"Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
The resistors seem to be OK. Measered the most of them and they all seem to be ok. All numbers can be read.
For the ESR-meter; i've sent an email to Russia (it's an ESR Micro from Mike Klykov) to buy two new ones. It really behaving strange, even though i've changed the batteries for new ones I see the battery indicaties switching from 3 stripes to 1, giving really strange worths, calibrating suddenly, etc.. Don't know what's wrong with it, and too bad, i don't know how to repair it.
Don't have 50V capicators, so...Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Can't check the capacitors with my ESR-meter.. Seems like it's on the end of it's life. It's giving strange values..
(Just like some weeks ago)
Dont have 50V/470uf.. 35V is to less i assume?Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
I know, but most of the time a good manner to get an idea. Higher temperature = lowering the ESR and bringing back capacitance for some time.. But not 100% reliable.
I replaced C214 und C215 with 16V of 25V low esr capacitors, Ltec RXK',s i'm using on a regular base for repairing. Will do, other devices repaired with those capacitors are working again for multiple years. Don't see any problem in that, they're OK.
I have an ESR meter, but need to desolder some of the capacitors to check them. Not yet done....Last edited by koektrommeltje; 02-24-2017, 05:39 PM.Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Hello,
Here for some help too. Same Imac, same PSU. Bought it with a not functioning PSU of which some parts were allready removed: c215 (470uF) and C214 (470uF), they were bulged. Then there was bridgerectifier D050 which was shorted defective between - and ~. Replaced those.
And still, it's not functioning. When i put on the mac, i see one led. Then led 234 are blinking after some seconds. The fan is moving a little bit, immediately stops and that's it.
I've taken a look at 50N04, possible allready...Last edited by koektrommeltje; 02-24-2017, 01:24 PM.Leave a comment:
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Re: Philips 42PFL7662d/12 problem: backlight?
So it's not necessary to swap the bd9897fs IC, since i've swapped the slave mosfet even though it was working well.
I'll modify it further more; will buy the resistors so i can complete the modification on both boards.Leave a comment:
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Re: Philips 42PFL7662d/12 problem: backlight?
Today i replaced all the MOSFETS and the BD9897FS again on the master. After that it played again.
I assume the MOSFET were faulty on the masterboard. Again: no visible damage to the bd9897fs
I also replaced the MOSFET on the slave, just in case. Want to do the other modification on the slave, but i forgot to buy the 4.7ohm resistors :X so i can't complete modify it.
Question:
-will that be enough, or do i really modify the slave complete?
-if it start up again, is there any necessary to swap...Last edited by koektrommeltje; 12-20-2012, 07:48 PM.Leave a comment:
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Re: Philips 42PFL7662d/12 problem: backlight?
Well, at the moment i don't see a thing on the screen. I repaired only the master. Some days later, the TV was giving the same problems. At the master inverterboard i only swapped the db9897fs chip and unsoldered and resoldered the sk4075 mosfets after having them checked. It worked then... for some days.
I've order new parts; going to replace the BD9897fs again on the master and also go change all the sk4075 mosfets. After that i'll mod the slave board completely.
I'm not sure, but i think...Leave a comment:
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Re: Philips 42PFL7662d/12 problem: backlight?
The master inverterboard. I swapped the BD9897FS driver IC and then it worked. And failed some week later or so.
The modifications with the resistor, capacitor and the 33v zener diode 33 are also visible on it.
The 33v is a normal zener diode.. although it should have been a 33V TVS Zener. That shouldn't be a problem i was told. Is this true?
The slave inverterboard at the right side.
And a picture with the master inverterboard left.
...Last edited by koektrommeltje; 12-06-2012, 05:44 PM.Leave a comment:
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Re: Philips 42PFL7662d/12 problem: backlight?
And it failed again... worked some week or so
What could that be? I only swapped the BD9897FS and made the modification as listed in the link from Philips.
How come this driver IC fails again? Is that because of bad mosfets?Leave a comment:
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Re: Philips 42PFL7662d/12 problem: backlight?
What i did between? Nothing, except that i programmed my logitech harmony remote control for this television and pushed some buttons and then there was power: the blue led on the front of the tv lightened up, the backlight went on.
Obviously there are two ways to power on/off the television. One standby (red LED), one compleet no voltage i think? It wasn't mine tv, so i didn't know that and ik didnt have the remote for it. But, i powered it on.. which wasn't the case earlyer obvious :X
Looking...Leave a comment:
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Re: Philips 42PFL7662d/12 problem: backlight?
[url]https://cdn.badcaps-static.com/pdfs/9da066f1bf189b3b41676b43f0f20fec.pdf[/url]
> The link for the modification for the specific inverterboard as advised bij Philips.
Im from the Netherlands and here the electricity is 230V.
Anyway, problem is solved at the moment. Only thing to do is the modification from the link here above so that it won't come back.
I only replaced the BD9897FS driver IC and programmed my logitech harmony for this device and pushed some power on/of buttons (after...Last edited by koektrommeltje; 11-26-2012, 10:21 AM.Leave a comment:
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Re: Philips 42PFL7662d/12 problem: backlight?
I will take some pictures of the televisions inside later this day and put them here.
I can't see any video. Using u flashlight isn't showing anything on the screen as far as i can see.
From the master inverter i swapped one capacitor, but the other one is ok. I'll swap that also later on. That's not the problem.
No.. the only visible thing i can do is putting the tv on and off with the standby button. And then i can see the red LED on the front of the tv.Leave a comment:
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Philips 42PFL7662d/12 problem: backlight?
Hi
I'm in need for some help to repair a Philips LCD TV which isnt functioning like it should: no video, no backlight. The only thing i can do is switch the tv on and off..
[B]The television:[/B]
Philips 42PFL7662d/12
LC420wu5
[B]The problem:[/B]
Well, the only thing i see is a black screen. No backlight, not even one second
[b]What have i done allready?[/b]
I googled, found out that this particular tv has bad inverterboards. Swapped the BD9897FS chip on the masterboard, checked the fuse on it, checked the SK4075 mosfet's...Last edited by koektrommeltje; 11-25-2012, 09:01 PM.
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