Suspect Bad PS Apple AcBel API 1PC36

[buz]

Hello Everyone -

This is my first post here and am unsure where (in the end) I'm going with this. I have been reading through the forums here the last few hours today and a few last night. The forums are 'full' of very useful information, particularly for someone like me who has some soldering tools but no more than 20 hours lifetime experience - . That said, from reading here I can see my limited soldering tools aren't gonna make it. A dual temp Weller gun (100/140), a Radio Shack butane soldering stick and some 40/60 solder - LOL.

I'm a building contractor and often have had to 'make do' with what I had, I don't think that is gonna happen this time. Something else I believe in is having the 'right tool' for the 'right job'. So enough of that ....

I have a G4 MDD I bought new early this century (lol) maybe around 2001/2. I did the PS replacement that Apple offered back then which is why I have the 360W PS. The last couple years the computer has had difficulties starting from time to time. My answer to that was never turn it off, well, one more power outage later and now it doesn't start at all. I've been through the Apple discussion boards a few times regarding this and the consensus is a dead PSU.

I have the PS out and open but one of the screws holding the board to the case is under a (don't know what it's called). Just behind where the AC plugs in is an off white squarish, 1/4"+ thick component - looks like adhesive under it (picture 2, upper right; picture 4, lower left) - and the 4th screw is inaccessible below it.

For all I have read here, I don't see any 'signs' of trouble with the PS .... nothing bulging, leaking, distorted. So where do I go from here?

[Toasty]

Re: Suspect Bad PS - AcBel AP|1PC36

First things first. The "pipe" symbol "|" is bad to use in a title. It'll never be found by a search and it's actually an "I" in the model number. Reported to moderators and I hope they change it. Secondly, "Apple" should be in the title too.

AcBel PSU for the Apple G4 units. Fairly common is the secondary caps are failed. Usually by bulging, but not always.

Start-up caps are also failures. Several discussions of these including one I answered last night regarding C43, which is a small cap towards the -center- of the board at the -end- of the middle heatsink.

Search for AcBel in here and Apple G4.

Severach has a good list of the caps in this supply here:

https://www.badcaps.net/forum/showthread.php?t=13985

Toast

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

Thanks for the heads up on the title errors - my bad!!!

Seems my searches turned up a few 'other' PSUs didn't find mine specifically. I'll go back and search again.

I'll probably need a little hand holding identifying 'secondaries' and C43 and such - but not yet - I'll study it a bit.

Looks like the mods repaired my title errors - thank you.

[Toasty]

Re: Suspect Bad PS Apple AcBel API 1PC36

Secondaries are the output caps where all the wires exit the unit. C43 is a start-up cap and the problem you describe sounds like that is at least one of the issues.

>>
I have the PS out and open but one of the screws holding the board to the case is under a (don't know what it's called). Just behind where the AC plugs in is an off white squarish, 1/4"+ thick component - looks like adhesive under it (picture 2, upper right; picture 4, lower left) - and the 4th screw is inaccessible below it.<<

That is the X-cap for filtering. Carefully remove or slice thru the glue/caulk to loosen the component so you can move it aside and gain access to the screw.

C43 location pic attached.

Toast

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

Thanks Toast. Here's some hand holding .... feeling a little inept atm, (shallowing pride) - so I did some more searching and found some new reading which was good. In one thread (I forget who) they said to 'pop out the power connector' where the main AC plugs in. I spent a cpl hours last night trying to figure out how it 'pops' out. Seems either it has to go with the board or the connections need to be de-soldered.

[Scenic]

Re: Suspect Bad PS Apple AcBel API 1PC36

i see spring clips on the socket.. try to push those in to pull it out of the casing..

[Toasty]

Re: Suspect Bad PS Apple AcBel API 1PC36

Yes, it has to (eventually) be unsoldered from the board, but you have to get the board loose first by detaching the X-cap ( post 4 ^^ ) from the board to get to the screw. The X-cap is also wired to the socket, so in either case, it needs to be loosed first. The socket (as Scenic said) has spring clips that you compress to slide the socket out.

Make sure you clearly mark or make a drawing of the wiring to the board from the socket to maintain Line and Neutral connections properly on reassembly.

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

@Scenic - yeah thank you, figured they had something to do with it ..... haven't quite figured how to get to the one on the back side, the case makes it tough to get at - I'm sure there's a way to pinch it.

@Toasty - and thank you, let the soldering (de-soldering) begin!!! This is where I most often foul up on something like this, leaving my bread crumb trail so I know my way back. For starts I'll photo each operation and if that doesn't capture it then I guess it's diagrams.

I haven't worked since last summer so cash is r-e-a-l-l-y tight and the proper tools are still in the store so this little project will be in process for a while. I'll resurrect it (the thread) as needed.

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

Well - came close to tossing the whole thing, but thinking I'll worry my way through - just don't have the right tools yet. My de-soldering was a 'mess' just getting the AC socket out .... sheeesh!!!

Located the C43 easy enough and see where the secondaries should be. Appears to be a 'mix' of sizes through there (below middle heat sink).

A couple photos (one of the messy plug) ... till I get better tools!

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

In order to get at the the caps mentioned I need to get the middle heat sink out. There were a couple screws from the bottom side that appeared to be associated with the heat sink - removed them, and the heat sink is still pretty solid. The only other thing (s) I can see are the 'mass' adhesive that was used and a couple nuts threaded to the sides of the heat sink - they appear to be fastening a component to the side of the HS. No way to get tools in on the nuts and the adhesive is - well - sheesh, they used alot.

Any thoughts on getting the HS out. Guess I'll get a multi-meter tomorrow too so I can maybe get an idea of what needs replacing.

EDIT: My mistake - there are 5 screws and nuts through the side of the heat sink. Looking impossible!!!

[Toasty]

Re: Suspect Bad PS Apple AcBel API 1PC36

None of those caps need the heatsink removed.

You'll only cause yourself a lot of grief if you do that.

Multimeter will be useless for cap replacement here. An ESR meter is what's needed to determine faulty ones.

Best bet, and you'll be sure to get them all, is the shotgun approach.

You'll need 12 caps here. Everyone from the end of the board at the secondary output side:

C7, 8, 10, 13, 16, 29, 21, 60, 59, 41, 35, & 43.

Oh, and invest in a decent 45W soldering iron and a spool of 1/8" (0.100") [blue] solder-wick. Plenty of decent irons can be had for $20 or less.

Toast

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

Ok thank you Toasty, music to my ears to not have to remove the heat sink.

Guessing one of these is what you referred to:
http://www.homedepot.com/buy/plumbin...kit-41707.html

Shotgun approach sounds fine. Guessing (again) I just deal with the adhesives as best I can to get it out of the way. (seems they were pretty liberal/sloppy w the adhesive stuff)

Kinda looking forward to this - figuring the worst that can happen is I'll have a PS that doesn't work .... same as I have now .

The replacement caps should be bought here?

[Toasty]

Re: Suspect Bad PS Apple AcBel API 1PC36

That'll work fine, and if you have a Radio Shack around they have the solder wick and a small roll of 60/40 rosin core solder.

Glue needs to be carefully cut/peeled away from components. Liberal application prevents undesirable noise (singing) of components at switching frequencies.

I don't know if -all- the caps can be purchased here. I -do- know they all can be had at Mouser or DigiKey.

You should be reading the site for info on how to determine what caps to use as replacements. Unfortunately, it looks like I'm going to end up giving you the info you need, which doesn't teach you anything. The old "giving you a fish instead of teaching you how to fish so you can survive" routine.

Toast

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

Toasty .... I know the 'giving' routine all too well. How about, lets see how I do on my first project with 'given' info. If I decide to do more then I can step in to the arena of determining bad caps etc. Hoping this is acceptable. I have been reading the site profusely and recall seeing talk about replacement parts, just have to find it again.

I have located all 12 that you mentioned, there are 3 others 'nearby' C53, 55 and 58 (? number is obscured) - I assume they weren't included for a reason .... just mentioning them.

I have the solder (60/40 rosin core) and will get the iron and wick soon. I've peeled away the adhesive necessary to get the ID's off the board and loosen the bunches of caps.

Will I need to reapply adhesive?

Should I start removing these so I can see what I'm replacing - so I know what to order? Guess if so then I better make a diagram of what goes where.

Your help is really appreciated.

[Toasty]

Re: Suspect Bad PS Apple AcBel API 1PC36

Adhesive - use a decent brand of silicone caulk. The "generic" brand from any hardware supply is fine. Ace/True Value/Lowe's/Home Depot. You do not have to apply it in such large quantities as the factory does.

>>Should I start removing these so I can see what I'm replacing - so I know what to order? <<

Yes. Dimensions(in mm) and values(uF & V).

>>Guess if so then I better make a diagram of what goes where.<<

Always make a map. It'll save your ass more times than not. Especially, if like many techs, you walk away or get involved in something else then come back to finish this at a later time. Pics also help in layout, colors of wire, what goes where, etc.

>>there are 3 others 'nearby' C53, 55 and 58 (? number is obscured) - I assume they weren't included for a reason<<

Actually 4 - C53 ,55, 56, & 57 - Not aware of a 58...?

Not included because they are not part of the filtering or start-up. Not a -usual- fail on such small value caps.

Toast

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

Great!!!

Have a fair idea of where I'm headed atm. It'll be a few days by the time I get the rest of the tools and have caps in hand ready to order ....

Thanks again Toasty.

[JOHNBOY]

Re: Suspect Bad PS Apple AcBel API 1PC36

This didn't occur to me the first time either but the glue they used hold the 470/680/1000/1000 together helps in getting them out, it will all just fall out as one piece when de soldered.

Also you didn't have to remove the power socket, all you do is remove the 4 screws holding the board, slide it back a bit and then turn it to the side and you have bottom access to the green and blue wire, which desolder very easy.

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

Well, it was easier than I thought removing the old caps. I imagine everyone comes up with a method that works for them. Couldn't find the right braid locally and wasn't up to waiting for mail order so got a little sucker. That was fine to get 'some' of the solder, but in the end alternating the heat side to side and rocking the component out worked well.

Have read through the forum here and am unsure which brand to get for replacement. I've seen recommendations for Panasonic, UCC, Nichicon and Nippon Chemicon and probably others. I know I'd prefer to pay extra for first class replacements. Oh - and of course which ever they are - they need to be low ESR.

For what it's worth I put the 12 caps in a chart listing their ratings and size (photo below). Think I got the wrong solder too - it's 60/40 rosin core but it's 1/16" - seems kinda too large for finer work. I believe there's a size smaller.

[Toasty]

Re: Suspect Bad PS Apple AcBel API 1PC36

To start to get an idea for replacements, list the manufacturer and series of each cap. Series is typically a 2 or 3 letter code near the temperature line. i.e.- SC(M) 105°C
SC is the series, the (M) indicates 20% tolerance and is assumed on most caps in these PSU's, so it's unnecessary to report that.

Standard diameters: 5, 6.3, 8, 10, 12.5

Example:
C16 2200/6.3 10x25 Teapo SC

Grab the Teapo SC sheet from: http://www.teapo.com.tw/products2006E.htm

Find your cap(s) and list their respective ESR(Z*) and ripple current.

{*Z = impedance but for the sake of discussions here it is regarded the same as ESR.}

Other manufacturer's sites can be found thru: http://capacitor.web.fc2.com/

UCC (the little shield emblem) - http://www.chemi-con.co.jp/e/catalog...m_diagram.html
Panasonic / Matsushita (the fancy M in a square [M] ) - http://www.panasonic.com/industrial/...tive-products/
LTec - http://www.ltec.com.tw/product_e.htm

Some series may be discontinued and not shown on the charts. I have some of those sheets as do others here. Don't be afraid to ask for them.

1/16" diameter solder is a little big, but is usable. 1/2 that diameter is better for most fine work.

Toast

[buz]

Re: Suspect Bad PS Apple AcBel API 1PC36

Made some progress but stumped by L-Tec and others that are not labeled w a manufacturer. Photos of corrected/updated data sheet from earlier and of caps without manufacturer labeled. The photo of the caps is of 2 caps each showing opposite sides - one showing side A and the other showing side B.

Seems something is wrong with L-Tec's site, couldn't find any data sheets. On the main product page the images are links but there isn't any data at the links. So idk???

Took me a bit to figure out what I was looking for at Teapo's site, simple afterwards.