Apple imac G5 614-0329 power supply

[dewi]

I have an old (1st generation) 17" imag G5 which was not working when bought and I have replaced the motherboard capacitors as in various posts on the www. [known fault]

First time tried, mac powered up to login[user] screen but went mental (fans running full speed) whilst I was looking up password removal etc. so powered off. Since then I have had varying success with powering up - stops at logo, no chime, goes to login etc. All quite random.

I have noticed, however, that the front light goes off at different times - it comes on and goes off quickly = no chime. If stays a bit longer = I see logo or it may go to login user screen.

Suggestion now is that it MAY be the power supply causing problems. I have not checked output voltages under varying conditions yet but I have managed to pull the covers apart and looked inside - no apparent 'bad caps' on the board but I suppose that one or more may have dried out and show no signs ?

Main problem is that the supply does not look anything like the 'usual' ones shown on the www for capacitor kits - not A,B,C,DD or EE. I have posted pics for your perusal - have you seen one like this before ?

Any suggestions would be appreciated - should I try logging voltages under different fail conditions to try and get a clue on what is wrong as a first step in fault finding ?

[Toasty]

Re: Apple imac G5 614-0329 power supply

Your location? Fill out profile please.

Looks European. As this is a Delta unit, it does not sound like a PSU problem.

Sounds like there are still issues with the motherboard. Perhaps you failed to redo the heatsink compound for the CPU? Did you clean out the cooling fins for the CPU/GPU air tunnel? Did you have that heatsink off of the mainboard while you worked on it?

Have you tried booting from the CD's? Have you done a "reset" of the board by holding down the correct button?

Is that picture of the screwdriver bit there for a purpose? Or, is that what you did to get the security screws out?


Toast

[dewi]

Re: Apple imac G5 614-0329 power supply

Thanks Toast, answers as follows :

Lincoln, UK. Yes, new compound on cpu lid/heatsink. Cooling fins blown out before refit. No Heatsink stayed in the case/lid unit. Got no OS-X CD's, boot is on 80Gb hard drive as purchased. Have done a hard reset (2nd button) on motherboard - no change to fault.
Screwdrive pic is tool used for dis-assembly. Philips screws not torx on this unit.

You ask 'did I have the heatsink off the mainboard' - as far as I could see there is no heatsink on the mainboard, or am I wrong ? The mainboard has the cpu soldered on to the rear (as you look in the case) and just the lid is exposed when the board is removed from the case. The heatsink seems to comprise of a large copper plate attached to the inside metal chassis, where you apply the heatsink compo, and the 'tunnel' bit, with fins, on the top of the board. Heatsink compo was 'white' sort - conductivity = 17 x 10-4 cal/cm sec (deg C) - whatever that means. Standard stuff.

Are the Delta units more reliable than others then ?

Should the power light on the front go on and off as I described ? Or does this show a power related problem ? Is the light the same as LED2 = power good ?

David

[Toasty]

Re: Apple imac G5 614-0329 power supply

Heatsink/air tunnel same-same. The fin side goes over the GPU. The CPU has contact with the mainboard and the copper back panel of the chassis. As long as it was cleaned and re-compounded you're okay.

I always use Arctic Silver for remounting CPUs.

Delta's don't have the wacky problems the others seem to. The caps are/were better brands to begin with.

I've not seen a power light do what you are describing. Typically they come on full brilliance and then go out once booted. IIRC, Full light and full fans if you go into command line mode too. Blink when in standby mode.

Could this be a bad hard drive?

I would go back over my work carefully and reflow any solder joints that look questionable and check all connections. It may turn out that the board was damaged before you got it.

See if you can get the OS X CDs. Check torrent sites. These don't run on anything above 10.5.8 Leopard. 10.3.x Panther and 10.4.x Tiger okay -> not Snow Leopard 10.6.

Without knowing its real "history", it's always a gamble.
i.e., Did the previous owner toss it across the room because it got screwed up?

Are you getting the 3 LEDs on ?

Toast

[dewi]

Re: Apple imac G5 614-0329 power supply

Retried this morning and it booted up OK, got in as user and reset date/time then system hung up and unable to proceed, clock second hand froze, no response from mouse or keyboard. still had all 3 led's lit (1,2+3).

Power up is as you said - led 1=mains connected, stby power. led 2= power OK, led 3= system doing something, eg disk activity. Front light dims and goes out (and stays out) with first lot of hard drive activity - booting up I guess.

After hanging up, removal of mains for a minute and re-powering up with rear button or board button(top) does not put front panel light on but does put led 2 on=power OK.

Does this suggest boot failure(motherboard error) ? The fact that the power good comes on consistently each time I power it up suggests, to me, that the power supply is behaving itself and is unlikely to require attention. Do you agree ?

A friend had a 'normal' imac G5 - in a tower case, and said his system behaved the same way until he replaced the video card (or had it reworked or something video related). Given that I have replaced a row of caps right next to the on board video circuitry maybe I should eyeball that area as a first step. I guess the top 'heatsink plate' covers the video chip etc. so a stripdown is required to get at it ?

I have downloaded OS-X 10.4 dvd's and burned them to dvd as .iso and .dmg (two different torrents) using a trial copy of MacDrive, which seemed to build an imagefile first. The .dmg dvd whirred a bit when I tried booting with the 'C' key held down but did nothing else and now is in the drive not wanting to come out again. I tried F12 on my windows keyboard to no avail. The front panel light was not lit when I tried this.

More comments appreciated.

[Toasty]

Re: Apple imac G5 614-0329 power supply

DVD stuck - hold down mouse button at power up and keep holding until it ejects.

Video problems present as scrambled or blank or lines/sparkles.

Hanging sounds like
- a mainboard/CPU issue with heat
- a bad OS load
- a bad hard drive
- OS may have crashed when this died for previous owner
- OS crash during an update

Can you determine what OS it is booting with?

Do the SMU reset button bit again.
Unplug, wait a minute, press button and plug back in, release button after a few seconds.

Getting the DVD's burnt correctly on Windows can also be a bit of a pickle. Remember to use a lower speed than what most software wants to. I use 8x to 12x to burn most discs on 48x drives.

Try using TransMac. Also available "out there". I use v8.1.

Toast

[dewi]

Re: Apple imac G5 614-0329 power supply

System appears only to be able to boot up once a day, then you get problems from then onwards.

Currently it is not even going as far as the chime. Either the front light stays off, or stays on. Both result in fans running up to full blast after some time - maybe a minute maybe longer.

When light was staying off I tried unplugging one stick of ram (1Gb) at a time and the front light would then come on. Now the light is on and staying on. I have tried it without the keyboard and mouse (they are daisy chained). I have noticed that the mouse, an optical one, has no light coming from it, not sure if this is correct or not, I seem to recall that on a PC the mouse does not light up until it has booted up.

In all cases leds 1 and 2 are lit (stby + pwrOK).

When it does 'work' the pictures / desktop are good, no lines, spots or stripes.

CD will still not eject with mouse button (R or L) held down during power up / boot or when using F12 on the PC keyboard.

It looks as if I will have to wait until the morning to find out which version of OS-X it is running (assuming it behaves when it has had a rest. I believe it is version 10 but no idea of rest of it (eg 10.4.3)

Thanks for your patience with me so far.

[Toasty]

Re: Apple imac G5 614-0329 power supply

Well, lets get a check on the PSU voltages then.

Without powering on, just plugged in, you should have 5vsb and 20-24vsb.

Once powered up (jumper 15 [green] to any black square), measure from any black square to the indicated voltages. 24v should be fully up now if it wasn't before.

You can measure these connected to the computer also. Power on by briefly shorting the 2 gold pins sticking up where the power button would be. You can use a couple of paperclips to probe in from the backside of the connector. Just remember to not short them and to "flip" the pinouts.

See these images for pinout. Images are -facing- the plug from PSU.

https://www.badcaps.net/forum/showpo...1&postcount=37





Toast

[dewi]

Re: Apple imac G5 614-0329 power supply

Update - 010512AM - First, got CD out of drive using mouse button. Yeah !!

Bootup from cold only went as far as apple logo and gearwheel, then hung up. So no go on discovering OS-X version yet. Next two tries = no light on the front.

Thermal compound is zinc oxide based and scored B+ in overclockers tests. Similar to Arctic Silver Ceramique. At least it cannot cause shorts if it splodges out.

Measurements on psu -

1. Not powered up: on/off = 5.1v; 24v = 0v; 5vs = 0v.
2. Powered up: 24v = 25.5v; 3v3 = 3.31v; 12v = 11.98v; 5v = 5.1v; 5vs = 5.1v.

I checked all the pins for correct voltages. So looks OK off load. Are there any easy to get at points on the motherboard to check the voltages under load ?

[Toasty]

Re: Apple imac G5 614-0329 power supply

>> 1. Not powered up: on/off = 5.1v; 24v = 0v; 5vs = 0v <<

Somehow, there's a wrong measurement there with the 5vsb & 24vsb...?
Can't get the 1st LED without 5vsb.

The running voltages look fine.

How long after you say it "hangs up" are you letting it sit running? Try letting it run for up 30 minutes. Without a hard drive activity light, you can't be sure that it's -not- doing anything. If the fans come up full speed, get the back cover on so the air channels work properly. Put the cord thru the back cover first so you can do this without powering off.

Toast

[dewi]

Re: Apple imac G5 614-0329 power supply

More info for you - got it to power up for a couple of minutes just now, before reading your reply above. I wrote down 5vsb = OK, read it as 0v, and then wrote that down here ... hence confusion.

OS is rev 10.3.9, CPU is 1.8G, RAM is 2Gb, ROM is rev 5.2.2f4. AND I got the CD out of the drive again.

Redid all power supply measurements, mains connected but no link in for ON/OFF: 5vsb = 5.01v; ON/OFF = 5.01v; 24v = 0v from pin 22 to any of the ground pins (just thought it might be separate and grounds 'commoned' on the motherboard when plug connected). Maybe Europe is different ?

Really annoying being 'so near yet so far'.

I will try leaving it 'hung' for a while as you say. So far I have turned it off after a minute or two. Lead through cover seems a good idea. I will let you know what happens.

[Toasty]

Re: Apple imac G5 614-0329 power supply

Don't understand why 24vsb is missing when just plugged in. I've a few similar Delta units, 2 from UK I'm goint to test. brb

Okay. Got it. Some of these Delta units have 24vsb and some only have 24v when switched on.
Per your PSU's label, yours does not have it at standby, just when it's on.

That said, your voltage readings are correct and good.

Toast

[dewi]

Re: Apple imac G5 614-0329 power supply

Further on 'hung' system.

First time got into OS-X and was reading HDD contents when it hung. Left for 40 minutes but could get no response from mouse or keyboard.

Second time got front light on but light stayed on - would not go off. Left 40 minutes again without anything appearing to happen. Would not power down using switch in usual manner (hold on for 10 secs) and could only shut system down by removing mains plug.

Should I try and probe power supply voltages (5v/12v/3v3) when hung up ? Or is it unlikely to be power supply problem ?

[Toasty]

Re: Apple imac G5 614-0329 power supply

Updated previous post re:voltages ^ ^ ^ ^

Have a PC with a SATA connection? I'd like you to pull the HD and test it on that using HDD Regenerator. Available from the "usual" sites.

[dewi]

Re: Apple imac G5 614-0329 power supply

Ran HDD Regenerator ver:2011 on 80Gb drive. Ran both quick scan and full scan / repair.

Both took 25 minutes and neither reported any bad sectors or sectors lost or delays - clean bill of health.

Looking more and more like bad joint/s or flaky component on motherboard. However I will get out the contact cleaner spray and try the connectors first.

Any other ideas ? Will be up for a bit yet (currently 00:07hrs here).

[Toasty]

Re: Apple imac G5 614-0329 power supply

I'm at a loss for more suggestions now. Maybe a bad connection or a bad solder joint, or as you said, another component on the mainboard. It still sounds like it could be heat related for either the CPU or GPU. Might want to pull it apart and make sure the CPU is making good contact with the heatsink.

Do you have some other RAM you can test it with?

[dewi]

Re: Apple imac G5 614-0329 power supply

Will try resorting heat sink and compound both sides this time and report back.

No ram to try yet, am bidding on 2x512Mb, Can I try one stick at a time ? If so, is either slot = slot 1 ?

[Toasty]

Re: Apple imac G5 614-0329 power supply

>>Can I try one stick at a time ?<<

Yes and either slot.

[Toasty]

Re: Apple imac G5 614-0329 power supply

BTW - What is the Delta DPS- number on your board?

Just had another 614-0329 problem get posted. Perhaps you can assist him as you might have an identical unit.

https://www.badcaps.net/forum/showthread.php?t=18352

Toast

[dewi]

Re: Apple imac G5 614-0329 power supply

Model number is - DPS-180QB A REV:02

I would not be very happy prodding around inside the supply with the mains connected. I seem to recall the mains is converted to 400vdc before being chopped. Burny fingers !

Thanks to your suggestion regarding the GPU overheating I redid the chip and the system seems to be behaving itself at the moment. It stayed solid for five hours last night during which I changed the hard drive, installed Tiger (OS-X 10.4.3), got on air, downloaded updates (247Mb of them !), installed the updates and then left it running for a further hour on 'soak test'.

Today I am seeing if it will behave from 9am to 10pm without falling over. It started up OK, which is a start.

I have attached pics of the GPU chip 'as was[GPU1]', with arctic silver dried out and over the caps next to the die top, then cleaned off before coating with arctic ceramique[GPU2]. I liked the heat marks on the chip, looked like it had been heat treated. I cleaned it all off with IPA and a cotton bud after I had removed the clear plastic 'mask'.

So, cross your fingers it stays OK.