Celetronix power supply for iMac G5: which transistor?

[gerard3]

Hi everyone,

I have an iMac G5 here, with this Celetronix power supply in it:

Power Supply for iMac (Apple part number: 614-0363)
Celetronix p/n: APP-22-LFM33, REV-X9B
AC input 100-240 VAC, 50-60 Hz.
DC output +12 VDC / 15,4 A

and I have two questions about it.

a) What is the name of the Q5 transistor in this power supply?
b) What is the value of the resistor that controls that transistor?

Hope you can help me. Thanks in advance!

Greetings,
Gerard (from the Netherlands, Europe).

[selldoor]

Re: Celetronix power supply for iMac G5: which transistor?

Are yours burnt out? try cleaning with IPA -have you a picture of that area of the board.
Please post it using manage attachments

[gerard3]

Re: Celetronix power supply for iMac G5: which transistor?

Thanks for your suggestions.
Yes, they are burnt out, due to a cooling problem that caused a short circuit. I will try to post a picture soon.

[gerard3]

Re: Celetronix power supply for iMac G5: which transistor?

Here are some photos, with a pen pointing at the components I mentioned in my post. (I hope they are detailed enough, because they were taken with a smartphone)

By the way... The output of the power supply itself is 12V, but what's the function of the brown wire at the bottom of the first picture? And what voltage should it have?

Thanks for your help!

.

[selldoor]

Re: Celetronix power supply for iMac G5: which transistor?

Sadly I cant answer any of your questions Most power supplies for pcs output 12v and 5v perhaps the brown should be 5v? - Cant make it out on the label. Or perhaps it is 12v+
12v- and separate ground, but only guessing.
Hopefully somone who has worked on one ( doesnt look easy) will help more.
Pictures are not close up enough for component level troubleshooting

[stj]

Re: Celetronix power supply for iMac G5: which transistor?

most mac schematics are available if you hunt on mule & torrent

[selldoor]

Re: Celetronix power supply for iMac G5: which transistor?

Found this some pics in it might help with the resistor value if they cover the part of the board you mean.
https://www.badcaps.net/forum/showth...t=15205&page=1

Also a few guesses at the brown wire if it is labelled PG then it likely
a powergood feedback to the main board

[gerard3]

Re: Celetronix power supply for iMac G5: which transistor?

OK, thanks for your replies!

Gerard.

[gerard3]

Re: Celetronix power supply for iMac G5: which transistor?

I still haven't found what I'm looking for, unfortunately.... But I found out that the name of the transistor (FET) is std5nm50 and that there's a resistance of 0.5 Ohm on "leg" 3.

I do have another one here, but it's a bit too big, so I will have to saw and file to fit it in.

Any suggestions and/or more info about the 'real' std5nm50?

[selldoor]

Re: Celetronix power supply for iMac G5: which transistor?

What part haqve you found? same but different package?
Is the old one still shorted when off the board?
Picture of them

[gerard3]

Re: Celetronix power supply for iMac G5: which transistor?

Update:
I have found a (new and complete) power supply now, and everything works perfectly again.
Thanks for your help everyone!

Gerard.