Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Its toast. beyond my want or needs at this point. I was thinking the Trash can would make a nice place for it. The switching circuit is dead from what I can tell. It will not turn on when I apply load to pin 4 from ground or any pins for that matter. This project machine will be a PfSense box for a production Web cluster and Cloud server so it will more than suite its needs.
rwing
Member
Last Activity: 08-02-2016, 07:30 AM
Joined: 07-24-2016
Location: Houston
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Thank you for the Pin out Sir. Yes the startup section of this psu is burnt. The pin out information you have provided me has now given me the opportunity to test my Logic board and prove that the board is still functional. I have modified an enterprise class power supply to power this logic board. I am typing from this mac logic board retrofit into an ATX Rack Mount Case running Debian 8.0 This system will now take another life with a different function.
P.S. any one need an Early 2009 Imac 24in Screen and Glass front cover....Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
..Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
SO since you have the Liteon version of this power supply is there any way you can test the pins and get the pinout for the power supply.. They are the same just different manufactures. The pins should be identical per they both power the same Logic Board.Last edited by rwing; 07-28-2016, 09:14 PM.Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Got a test bulb; however, when applying a load to the 12v side I got nota.Last edited by rwing; 07-28-2016, 05:57 PM.Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Yea my math is way off. OK Avg 12v car bulb is around half amp so that makes about 24ohm load not .9-1.1. Sorry for inconvenience. OK so tomorrowLeave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Ok so then this presents a stand still. This however is a 300W resister at 1ohm. A standard dimmer bulb from an old Chevy is .9 -1.1 ohm load. This even though its bulk is not much of a difference for load I would presume. it would function the same, as the resister gets hot just like the filament the Rt goes up with it. In this case the 300w resister will take much more amperage about 25 amps at 12 volts to meet its potential. that's just my opinion. Ok well if we are at a stand still I will then gather a 12 volt testing light around .9-1.1...Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Alright well I have had a difficult time finding a 12 car bulb but I have just as equiv for load. I have a 300w 1ohm test resister that should do the trick. no light to turn on but I can tell you if when it gets warm its providing a load. I can surely measure the voltage drop across it if and when this PSU turns on.
see photo....Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
I'm more than comfortable with this per I am a Cathodic Protection Specialist and I deal with Large Scale Rectifiers on a daily basis. 480v 3ph primary's rectified down to on avg 50v 100a dc constant voltage units. I just don't want you to feel obligated to go any further per im sure this may turn into a step by step break down of how to properly troubleshoot at PSU. like I said I will follow down the rabbit hole as far as you are basically will to go. I understand all safety concerns per I am NFPA 70E certified to 500vac.
...Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Mr. Toasty,
I really appreciate you're assistance and honestly we may be breaching the extent of my electronics knowledge. I am 100% invested into this and I am stubborn enough to follow threw. I will go into this as far as you are willing to go.Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Both Caps Read 160vdcLeave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
I get 160vdc across the 2 outside pins on the bridgeLeave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
See attached photos of the top of this PSU...Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
See attached Photo...Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
The Multi meter is set vdc (Auto ranging), Its a fluke 87 V and its calibrated Yearly. My negative lead is placed on Case ground (See next post for what appears to be issues with grounding on the board). The board is grounded to Case via screw holes. When reading the caps I am reading the (+) on the large brown 450v caps that are laying on their side. Both caps read at +77.2vdc and when I read the neg on the cap they read -75.4vdc. Standby for Bridge diode reads.Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Main fuse is good. Fuse is soldered to board so testing this as follows: when AC applied I read 120vac on both sides of fuse, Good fuse (Closed circuit)
Output from the Main Power Caps = 74.5vdc. When AC removed they trickle down. Caps look clean. Not domed or cracked, no discoloration on the board anywhere.
as far as the mosfets are concerned I believe I need to De solder those to test fully; Each of the Mosfets on board read either OL or >150ohm from the Source to the Drain. Now I read the Drain from the...Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Sweet, Thank you for the fast response. Ok so I have identified the 4 grounds on the plug. The power supply will simply put will not power up. When I provide proper 120 volts to unit the entire 12vdc and 24vdc (24v monitor output) is dead. Bottom line is, even though I am fairly Decent around DC electronics without knowing what the pins are 12v what pin is the Power/on pin, I would not be capable of utilizing an ATX power supply as its replacement. I guess the biggest issue im concerned with is, that since this PSU is bad its very difficult...Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Sorry its a 12 pin connector not 6Leave a comment:
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Re: iMac 24 PSU LITEON PA-3241-02A1 250W
Hello All,
My name is Richard and I am new to this forum, I have been pulling my hair out looking for a Pin out of the 6 pin PSU to Logic board. I have managed to find grounds and that is about it. I truly believe my PSU to be toast but I have no means to prove this per I cannot get the Logic board to display any forms of life. without a means to power the system. I would hate to replace the Logic board since I have 2109480129.2 (Exaggeration) ATX power supply's laying around that function. Before I dive into the schematic...Leave a comment:
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