Latest Casualty ...

[GorfTheChosen]

it is actually not a bad idea to learn how to fix the PSU yourself when it dies, ...

I'd agree.

In fact, it's not a bad idea to be able to learn how to fix anything when there's a problem with it.

but otoh a good soldering kit is like 50 dollars,

I have several cheap soldering irons, along with one fairly decent one ... but decent Weller station off eBay is on my list, along with a hotair gun.

it is more than one hour work, you can fuck it up if you dont know what you are doing, you have to find the right parts before...

I still have a bit of a runway as far as feeling entirely comfortable with doing soldering work on PCB's - especially on something that still has considerable value to me (both economic and sentimental  )

Both of these machines are one-owner - me - I purchased them new at the time they were current models.

Parts might be available thru Digi or Mouser or some place like that ... or fleabay.

Having said all that, when the G4 800 took its dump a few days ago I was about to order a cap kit off Amazon for the power board in an old Samsung display that died a few years ago.

I also have several breadboards and a dead PSU that I replaced (20 years ago ?) out of an 8100 that I can practice on if I really get the itch and I decide it needs scratched.

[FdB]

Except for one small cap (behind the orange wires) in the first image, I don't see any signs of anything leaking or being swollen.

Yup, that green capacitor with da puffy top is most likely ka-put. Those green caps (TEAPO brand - are junk. They're in the MDD PSU's too). Might as well replace 'em all. (Except for those big fat black ones - unless they're puffed or leaking.) Disassemble completely, taking pics as you go and become familiar with the negative & positive legs and their configs on the board for each cap so that new ones will go back in correctly. Once you have 'em all out and their individual specs noted - Digi, Mouser, etc. can provide replacements for less than you might ever imagine. Draw yourself a map / legend of where all the caps are located along with spec notes for each individual cap and their positive /negative leg orientation on the board.

A couple of things...

Solder wick - flat braided copper (to remove old solder cleanly from the board). If you're not into paying for a solder station, wick's a good way to go.
Chip-Quik. A wonderful little product that also helps in solder removal. You'll get the hang of it's use fairly quick and love it.
Solder Sucker. NO. Too much trouble from these spring-loaded pieces of crap... that get clogged and simply just drive you nuts.
Opti-Visor magnifier or a flex-neck mounted magnifier and some point light to illuminate the work spot.

If you're serious about delving into this, I can provide more info and pics to possibly help, tomorrow?
I think everyone should try this little exercise at least once.
If unsuccessful, a warm appreciation of Andy's services can definitely occur.
If successful, well then there's that warm fuzzy feeling of accomplishment.
It's bedtime here... g'night all.

[GorfTheChosen]

Yup, that green capacitor with da puffy top is most likely ka-put. Those green caps (TEAPO brand - are junk. They're in the MDD PSU's too). Might as well replace 'em all. (Except for those big fat black ones - unless they're puffed or leaking.) Disassemble completely, taking pics as you go and become familiar with the negative & positive legs and their configs on the board for each cap so that new ones will go back in correctly. Once you have 'em all out and their individual specs noted - Digi, Mouser, etc. can provide replacements for less than you might ever imagine. Draw yourself a map / legend of where all the caps are located along with spec notes for each individual cap and their positive /negative leg orientation on the board.

Sounds like a plan.

A couple of things...

Solder wick - flat braided copper (to remove old solder cleanly from the board). If you're not into paying for a solder station, wick's a good way to go.
Chip-Quik. A wonderful little product that also helps in solder removal. You'll get the hang of it's use fairly quick and love it.
Solder Sucker. NO. Too much trouble from these spring-loaded pieces of crap... that get clogged and simply just drive you nuts.
Opti-Visor magnifier or a flex-neck mounted magnifier and some point light to illuminate the work spot.

Yeah ... I have some solder wick here already. Bought for another repair project ... which I have yet to get to ... 

And I've been looking to get something as far as an illuminated magnifier ... my biggest problem these days with seeing, especially small stuff indoors, is there never seems to be enough light.

If you're serious about delving into this, I can provide more info and pics to possibly help, tomorrow?

That would be great.

What I'm most serious about delving into (personally, at least), is repairing the the power board for the Samsung LCD monitor (it was a nice monitor ... that I really liked  ), which I removed from the display in the last week. The cap kits are around $10 - $15 on Amazon, and it's a flat board, which should be easy to work on ...

On the G4 800 PSU, I'll likely send it to Andy, depending on what I hear back from him on a quote and the estimated turnaround time. I'd like to have that machine up and running as soon as I can.

I think everyone should try this little exercise at least once.
If unsuccessful, a warm appreciation of Andy's services can definitely occur.
If successful, well then there's that warm fuzzy feeling of accomplishment.

Makes sense to me.

Pic of the board I need to recap:

[FdB]

That Samsung power board looks like a good place to begin… nice and flat, plenty of surrounding space to work on the individual caps and not too much of that white goopy, glue-ish stuff to remove. In fact, none of that on any of the caps with marked tops that I presume were marked as questionable or slated for replacement. (The QS AcBel PSU is a slightly different story.) From your pic, looks like there are 6 primary caps marked & slated for replacement. So you could spend $10- $15 for that Amazon cap kit OR once primary suspects are removed and specs taken from the sides of each cap… maybe less than $6 ordered from Digi or Mouser. (But then there’s the minimum shipping costs to also figure in.) BUT you’d get to choose which brand of caps you’d like. AND if you wait to order all your caps (for the AcBel PSU too) there’s only that one shipping charge to figure in.

I pulled the board out of the AcBel PSU housing last night and it looks like there are six of the TEAPO caps (most of them with swollen tops) that it’ll need. (One on the attached, fan control board.) I think GaryN provided the technical-term name for that white goopy, glue-ish stuff… but I don’t remember it now. Anyway, there’s much of that in the AcBel PSU to contend with. [I remain unafraid.] Sometime in the next week or two, I’ll have those TEAPO caps out and you could then add them (exact specs) to your Samsung LCD cap order… along with some of the items in my possible “shopping list” for you?



I try not to order anything from the Bezos Syndicate. Especially after they built a freakin’ fullfilment center a block and a half from my home. (+30% on my property taxes in one year!)

Anyway…



I’ve got a Weller WPS18MP / 60 Watt soldering “pencil” about two years ago and it has worked very well for me. (Returned the first one of these that I purchased as it did not work at all.) Many bad reviews of them online but evidently I got a good 2nd one. [I really want a Hakko soldering iron but have yet been able to self-justify that expense.] I think that both Lowe’s & Home Depot carry the Weller. Around $30.00. A welcome, lightweight replacement for my old Radio Shack iron and it also features a little LED work light. It is not a cordless device although they probably make a cordless version.

CAIG brand, Tip Tinner & Cleaner. Normally use this after the iron first heats up and then when finished before storing the iron. (Sometimes during the session too if it’s a long session.) Also use a four-folded paper towel to wipe excess from a hot iron before soldering / de-soldering. Not costly but well worth whatever is does cost.

CHIPQUIK SMD1 - SMD Removal Kit (Around $10.00 if I remember correctly.) Rarely do I ever use everything in the kit… but I do use the SMD291 tack flux (tube) that comes with the kit. Seems to help with solder removal. (With many thanks to MacOSPlus for the ChipQuik referral.)

Solder Wick. Size #4. I use hemostats to grab and hold opposing sides of the wick to expand it a bit and this seems to help with heating and removing solder within the wick. (Shorter tip-on-board time.) And with the help of fingernail clippers (or actual snips made to cut smaller electronic items) I trim the used wick from the wick end, as I go. Clippers are also good for trimming legs of the caps after installation.

I’ve a “Bio-Therapeutic” magnifying visor with several different magnifying lenses included ($3.00 at the thrift store.) It also has a light-over-lens light. But I still have an original Opti-Visor and various other, stationary desktop magnifiers but It all depends upon how long the session might be or if it’s merely a “quick one”. (Have one of those articulated, mounted magnifiers with the alligator clips for very small… or “wire work”.) And I sometimes use “Pony” clamps to hold and stabilize larger boards like the MDD PSU’s.

Tweezers!

I’m certainly no authority on any of this but I had success with an MDD AcBel PSU previously. Refer to this thread: http://macos9lives.com/smforum/index.php/topic,4088.msg28012.html#msg28012 Lots of good info contained therein, and not really so much from me.

If you’re not going to tackle the QS PSU, I might hold off on this one. BUT I am thinking about using an extreme heated X-Acto knife blade to slice through that white goopy stuff… just for fun.

*Please do let everyone know Andy’s estimate? And mention the forum, just in case he’s still offering us a discount. Thanks.

[IIO]

my impression that repairing a broken PSU is unmanageable rocket science grows with every post here.

[GorfTheChosen]

my impression that repairing a broken PSU is unmanageable rocket science grows with every post here.

 

[GorfTheChosen]

That Samsung power board looks like a good place to begin… nice and flat, plenty of surrounding space to work on the individual caps and not too much of that white goopy, glue-ish stuff to remove. In fact, none of that on any of the caps with marked tops that I presume were marked as questionable or slated for replacement. (The QS AcBel PSU is a slightly different story.) From your pic, looks like there are 6 primary caps marked & slated for replacement.

It's actually not my pic ... it's the seller's, who's selling the cap kits on Amazon.

There are actually multiple sellers on Amazon, selling these cap kits - I just used the one who posts a pic of the board ... to show the relative ease of working on that board vs. a PSU where one has to contend with significant amounts of that white goop that's slathered over quite a few components.

While I have not definitely verified it by an exacting comparison of the kits they offer, it seems the parts that go bad are a known thing on those displays (that kit covers multiple displays I believe)

So you could spend $10- $15 for that Amazon cap kit OR once primary suspects are removed and specs taken from the sides of each cap… maybe less than $6 ordered from Digi or Mouser. (But then there’s the minimum shipping costs to also figure in.) BUT you’d get to choose which brand of caps you’d like. AND if you wait to order all your caps (for the AcBel PSU too) there’s only that one shipping charge to figure in.

OTOH, there's other stuff I need (not available at Digi or Mouser) that's already in my cart at The Borg ... 

I wonder, if after some 20+ years, Digi would still have my account info on file ... 

BTW - I was wrong: both of these G4 PSU's are AcBel's ... the Delta PSU came out of the Power Mac 8100.

Further response coming to the rest of what you wrote shortly ...

[ssp3]

FdB, take the picture of the underside of that PSU board and post it. Swapping those Teapo-cheapo caps is fine, but the trickle power cap is much smaller and located somewhere else.
And, please, guys, don't be cheepskates and buy genuine caps from reputable distributor, not some "kits" on Amazon. These days fakes are everywhere!

[GorfTheChosen]

I pulled the board out of the AcBel PSU housing last night and it looks like there are six of the TEAPO caps (most of them with swollen tops) that it’ll need. (One on the attached, fan control board.) I think GaryN provided the technical-term name for that white goopy, glue-ish stuff… but I don’t remember it now. Anyway, there’s much of that in the AcBel PSU to contend with. [I remain unafraid.] Sometime in the next week or two, I’ll have those TEAPO caps out and you could then add them (exact specs) to your Samsung LCD cap order… along with some of the items in my possible “shopping list” for you?

Yeah ... I could actually do that ... hold off on ordering the caps for the Samsung until later. I really don't have an immediate need for it ... other than to just get it off the bench to make room for some more crap.

I try not to order anything from the Bezos Syndicate. Especially after they built a freakin’ fullfilment center a block and a half from my home. (+30% on my property taxes in one year!)

Ouch.

Anyway…

I’ve got a Weller WPS18MP / 60 Watt soldering “pencil” about two years ago and it has worked very well for me. (Returned the first one of these that I purchased as it did not work at all.) Many bad reviews of them online but evidently I got a good 2nd one. [I really want a Hakko soldering iron but have yet been able to self-justify that expense.] I think that both Lowe’s & Home Depot carry the Weller. Around $30.00. A welcome, lightweight replacement for my old Radio Shack iron and it also features a little LED work light. It is not a cordless device although they probably make a cordless version.

This is what I currently have here. I think both were picked up at the local electronics supply store before they went out of business.

The Lenk is 25w and Made In the USA and appears to be pretty cheap. The ECG is 40w, dunno where it was made but it's a little nicer ... came with 6 - 8 replaceable tips of different sorts.

[GorfTheChosen]

CAIG brand, Tip Tinner & Cleaner. Normally use this after the iron first heats up and then when finished before storing the iron. (Sometimes during the session too if it’s a long session.) Also use a four-folded paper towel to wipe excess from a hot iron before soldering / de-soldering. Not costly but well worth whatever is does cost.

CHIPQUIK SMD1 - SMD Removal Kit (Around $10.00 if I remember correctly.) Rarely do I ever use everything in the kit… but I do use the SMD291 tack flux (tube) that comes with the kit. Seems to help with solder removal. (With many thanks to MacOSPlus for the ChipQuik referral.)

Solder Wick. Size #4. I use hemostats to grab and hold opposing sides of the wick to expand it a bit and this seems to help with heating and removing solder within the wick. (Shorter tip-on-board time.) And with the help of fingernail clippers (or actual snips made to cut smaller electronic items) I trim the used wick from the wick end, as I go. Clippers are also good for trimming legs of the caps after installation.

Good info, thanks.

Based on the other thread you linked, I'll have to see what I've got in the way of solder wick ... it might be junk at this point if it's unsealed (it's been stored in an unheated outbuilding for quite a few years)

I’ve a “Bio-Therapeutic” magnifying visor with several different magnifying lenses included ($3.00 at the thrift store.) It also has a light-over-lens light. But I still have an original Opti-Visor and various other, stationary desktop magnifiers but It all depends upon how long the session might be or if it’s merely a “quick one”. (Have one of those articulated, mounted magnifiers with the alligator clips for very small… or “wire work”.) And I sometimes use “Pony” clamps to hold and stabilize larger boards like the MDD PSU’s.

Tweezers!

Good deal ... yeah, there's a few things I need to pick up to make this a little easier.

I already have a stand for the soldering iron with a little rectangular dish for a wet sponge. And a pair of articulatable alligator clips on a weighted metal base which I have used for wire work. (Next project for that is soldering in a new fan on a LinkSys Gigabit ethernet switch to see if that restores functionality or whether it has already fried itself ... just need to pickup some heat shrink tube)

Hemostats, etc. ... could use a little more in the way of tweezers, picks and probes though. Have to see what we have that I can appropriate 

Biggest thing is probably lighting and magnifying solution. And some clamps.

I’m certainly no authority on any of this but I had success with an MDD AcBel PSU previously. Refer to this thread: http://macos9lives.com/smforum/index.php/topic,4088.msg28012.html#msg28012 Lots of good info contained therein, and not really so much from me.

If you’re not going to tackle the QS PSU, I might hold off on this one. BUT I am thinking about using an extreme heated X-Acto knife blade to slice through that white goopy stuff… just for fun.

You have one in particular you like ?

*Please do let everyone know Andy’s estimate? And mention the forum, just in case he’s still offering us a discount. Thanks.

Will do ... and thank you for your insights.

[GorfTheChosen]

FdB, take the picture of the underside of that PSU board and post it. Swapping those Teapo-cheapo caps is fine, but the trickle power cap is much smaller and located somewhere else.
And, please, guys, don't be cheepskates and buy genuine caps from reputable distributor, not some "kits" on Amazon. These days fakes are everywhere!

Good point.

[FdB]

I'll get an underside pic posted tomorrow.
AND be back with more... blabber.

[GorfTheChosen]

A few random thoughts:

As part of my journey on the way to here, ran across an individual doing board repair and/or restoration. Dunno exactly how I found him, possibly could have been a commenter on japamacs website or somehow connected to him (Apple Discussions maybe) Anyways, he had a couple of posts on his own site about getting into that field which I found interesting. Even possible that he's a member here, don't know. I'll include the link, as it may be of use to someone, as he discusses his setup/tool kit in a couple of posts:

https://thehouseofmoth.com/logic-board-repair-two-years-later/

After looking around on eBay for a bit, the thought has occurred to me that just getting another Power Mac G4 could be a fairly quick solution to the problem I was trying to solve (dead computers) The upsides are that they are relatively cheap and often a good bit more powerful than what I presently have (feeling the 1.42 DP MDD lust  ) ... downsides are that they vintage now too, and likely will need repair work in the future.

While I wait for a quote on getting those two power supplies repaired, a more immediate solution would seem to be just proceeding with the ATX--->G4 PSU replacement. This would do a several things: 1. provide immediate access to one of the machines (and the files stored on it's hard drives), 2. serve to confirm whether or not I actually have a bad PSU or that it's something else, and 3. provide a back up PSU in the event of another failure in the future.

Since (theoretically) the only thing getting modified is an ATX PSU extension cable, it's a relatively cheap and easy solution to implement. A single ATX PSU could serve as a back up for multiple machines of different generations, all for the cost of ATX PSU extension cable. (IOW: about $5 or $6 bucks per PSU variation)

The only uncertainty I have at the moment is whether the +25v ADC power, which the ATX PSU lacks, plays any real part in the workings and operation of the logic board, beyond just powering an attached display.

As I mentioned in another thread, I recently got the Power 9600 fired up again with the Sonnet G4/450 installed in it. The original hard drive had 9.1 installed and I went ahead and installed OS X 10.3 on an IBM fast and wide drive I had hooked to the 9600's external SCSI bus via a 68-pin--->50-pin adapter. Would have installed 10.4 ... but I couldn't get the 9600 to see the firewire-attached DVD drive.

10.3 seemed stable - once I figured out I needed to use PostFactor slow down the processor during the early phases of booting OS X to get it to install.

However that changed when I tried to install the ATTO ExpressPCI SCSI card, so I would be able to use the Ecrix VXA-1 tape drive to to access some old back ups. While the ATTO card saw the tape drive, Retrospect didn't. So at that point I pulled the ATTO card and tried an Adaptec Power Domain 2940UW. I think at this point I've traced the tape drive problem to an issue with the Retrospect installation (requires their "Advanced Driver Kit" to use that particular device) - after reinstalling Retro it sees the tape drive - although I haven't tried to access and restore any of the VXA-1back ups yet (Just as an aside, I did use Retro to access, re-catalog, and then restore about six or eight 15 year-old back up sets that I had on DAT. It went off without a hitch and the files seem fine - which kind of surprised me, given that they had not been accessed for 15 - 20 years)

Still haven't solved the finickiness of the ATTO card ... which is kind of disappointing in that it appears that the Adaptec card definitely will not work for hosting an OS X boot drive. I'm not entirely sure whether the ATTO will either for that matter. But if it's possible I'd like to set it up that way.

[FdB]

FdB, take the picture of the underside of that PSU board and post it.

As per ordered:

[FdB]

Clean-up bits…

Figured that might not be your pic of the Samsung monitor board.
Same email address as 20+ years ago? Easy enough to check / renew with Digi.
RE: Borg shopping cart. Resistance is not futile.
Both AcBel PSU’s you have - slightly different wiring harnesses?
I’d remove the caps (marked on that pic) from the Samsung and begin the caps list.
(You could even check their resistance / continuity with multi-meter while you wait.)
Bezos sucks / blows, etc. Race to the bottom.
I like the 40W ECG. Maybe a fresh tip? Might need more heat. Samsung will tell.
0000 steel wool and then blow the old solder wick off well (until new wick arrives).
(My historic and often habitual use of steel wool makes many here cringe.)
Lights? Flex-neck + normal light bulb base - LED bulb(s)? 3-5000˚K



Magnifiers? (I’ve spares that could be mailed. PM me that address? You cover postage.)

“One in particular that I like.”  / One what? X-Acto knife blade?

And RE: your last post…

If thehouseofmoth is attempting an MDD Samsung PSU resurrection… his yarbles are much bigger than mine. (I’ll stick with the AcBels and the Deltas.) Samsungs are too jam-packed for my taste and much more difficult to disassemble IMO. AND when a Samsung PSU bites the dust, it’s usually an extreme and “catastrophic failure”. (per Andy.) Think he also included the word violent in his description.

Regarding the 1.42 MDDs… I’ve a pair that I rarely (if) ever boot. Prefer the elegant “simplicity” of the 1.25 MDD und the Quicksilvers. One could always overclock those IF  that little increase in processor speed is that desired. I don’t waiver much from stock specs and hopefully reduce instances of instability. YMMV (Maybe why I’ve yet to succumb to the ATX PSU path?)

Perhaps one of your now-targeted & eventually resurrected machines would handle the tape drive & ATTO card better than the 9600? / K.I.S.S.?

Hopefully ssp3 can enlighten us as to the mysterious trickle power cap location. Also, perhaps the same for the MDD PSU? http://macos9lives.com/smforum/index.php/topic,4088.msg28011.html#msg28011


ooooh, clickable image

my impression that repairing a broken PSU is unmanageable rocket science grows with every post here.

Perhaps IIO is confusing rocket surgery with brain science? (Dain bammage?) 

[GorfTheChosen]

Clean-up bits…

Figured that might not be your pic of the Samsung monitor board.

Yeah, it's not.

Same email address as 20+ years ago? Easy enough to check / renew with Digi.

Nope ... different email. But yeah, would be easy enough to check.

RE: Borg shopping cart. Resistance is not futile.

Probably not.

Both AcBel PSU’s you have - slightly different wiring harnesses?

Yes. Slightly different wattage outputs and model numbers as well, IIRC.

I’d remove the caps (marked on that pic) from the Samsung and begin the caps list.
(You could even check their resistance / continuity with multi-meter while you wait.)

Would give me something to do while I wait for the CDs for Tiger to burn ...

Bezos sucks / blows, etc. Race to the bottom.

Yeah ... I'm not terribly keen about what I've heard about they treat the hired help.

I like the 40W ECG. Maybe a fresh tip? Might need more heat. Samsung will tell.

A fresh tip I can do. Have to see about a new sponge as well.

0000 steel wool and then blow the old solder wick off well (until new wick arrives).

I'll have to see if I can round up the solder wick.

(My historic and often habitual use of steel wool makes many here cringe.)

Lights? Flex-neck + normal light bulb base - LED bulb(s)? 3-5000K

That's what's illuminating the photos I posted of the PSU's - a simple flex neck with maybe a 60w or 100w 5000K LED bulb clamped onto the shelf on the bench. It's a little dicey though, since one side of the spring clamp jaws are broken. Still trying to find that piece so I can glue it back together.

I have an articulated desk lamp that swivels and you can raise and lower ... but I'm still looking for the rest of the parts to the base for that ... that's what I'll use ... once I find the rest of the parts for it.

Magnifiers? (I’ve spares that could be mailed. PM me that address? You cover postage.)

Appreciate the thought.

“One in particular that I like.”  / One what? X-Acto knife blade?

A heated one ...

And RE: your last post…

If thehouseofmoth is attempting an MDD Samsung PSU resurrection… his yarbles are much bigger than mine. (I’ll stick with the AcBels and the Deltas.) Samsungs are too jam-packed for my taste and much more difficult to disassemble IMO. AND when a Samsung PSU bites the dust, it’s usually an extreme and “catastrophic failure”. (per Andy.)

If AcBels and Deltas aren't jam-packed, then the Samsungs must be truly impressive ...

Regarding the 1.42 MDDs… I’ve a pair that I rarely (if) ever boot. Prefer the elegant “simplicity” of the 1.25 MDD und the Quicksilvers. One could always overclock those IF  that little increase in processor speed is that desired. I don’t waiver much from stock specs and hopefully reduce instances of instability. YMMV (Maybe why I’ve yet to succumb to the ATX PSU path?)

That could very well be ... but possibly a wise move on your end ... 

As far as the variations between the 1.25 and 1.42 go, I'm not really up on that ... although I think I did run across something about some issues with the 1.42.

Perhaps one of your now-targeted & eventually resurrected machines would handle the tape drive & ATTO card better than the 9600? / K.I.S.S.?

Perhaps ... but I just gave the ATTO card another shot and it freezes the cursor at the grey screen every time no matter what I do (SCSI devices connected/disconnected/powered on/powered off etc.) Both LEDs on the card are lit, indicating that it is terminating the bus high and low ... with wide devices on both the internal and external connections. It should not do that - termination on the card should be disabled I believe.

After that little exercise I pulled it and stuck the Adaptec back in and while the computer boots fine, nothing shows up ... no SCSI devices or the Power Domain card itself. And both ends of the chain (internal and external) are terminated.

Apple System Profiler, SCSI Probe, ATTO Express Pro Tools, Power Domain Control, nor the Adaptec flasher see the card ... WTF ?

I'm almost ready to heat up the oven and toss the ATTO in and see if that does anything for it.

Hopefully ssp3 can enlighten us as to the mysterious trickle power cap location. Also, perhaps the same for the MDD PSU? http://macos9lives.com/smforum/index.php/topic,4088.msg28011.html#msg28011

my impression that repairing a broken PSU is unmanageable rocket science grows with every post here.

Perhaps IIO is confusing rocket surgery with brain science? (Dain bammage?) 

No idea.

[ssp3]

FdB, I looked at the picture but that wasn't it. As I said in my first post to this thread there must be a string of high-ish value resistors connected in series somewhere and a cap after that string. IIRC, these were surface mount in my PSU. I repaired mine some 5-7 years ago and can't remember everything.. Maybe they were on the other board that sticks out vertically. If you post a picture of it from both sides maybe I'll be able to help furter.

[FdB]

Here’s what I refer to as the “Fan Control Board”.
Hadn’t considered completely removing this board as access to remove & replace that one green TEAPO cap is easy enough from the back side.


*Note white dot on PCB, corresponding with gold stripe on the TEAPO capacitor.


Back view

[ssp3]

OK, see that green wire? What's written on the main PCB besides it? ON/OFF !
From what I can see from the pictures, the trace from the green wire goes to Pin 2 of the sub-board. Also, the trace from pin 1 of the sub-board goes all along the left side of the main PCB down to high voltage part. That must be it, the start-up part.
My guess is that one of the light-green caps must be at fault. You can't determine which one is bad by simply looking at them. They might look OK, but measure faulty. (I measured mine with LCR bridge). Exchange them all, while the PSU is dissasembled and see what happens. If nothin else is burned and symptoms were "not starting up after sitting idle for some long-ish time", I'll give 90% probability that it will work.
Do not try to remove the sub-board, you will damage the main PSU! Try to work on it as it is. Slowly and carefully. Make sure not to desolder any SMT parts accidentaly. Use fine tipped soldering iron. If needed use file tool on the tip.  Also, note the polarity of the caps. Best way is to put a mark on the board.
Good luck!

P.S. My PSU was different (Delta?).

[GorfTheChosen]

Quote from Andy was $130 to refurb both PSUs if they were sent in together. No discussion of whose dime return shipping will be on, so I'd guess it would be mine. Might account for the slightly cheaper price than what he posts on eBay, where he covers return shipping back to the customer. Dunno, hafta see.

Found the solder wick ... it's NTE and still in the sealed package, a little dusty on the outside but probably not too much worse for wear.

The 3rd (of 4) OS Tiger Install CDs should have burnt and verified while I was having my afternoon nap. Using Fetch to FTP the Toast images down to Power Mac 9600 from the Mini to burn is working well. Kudos to GaryN for the suggestion.

It appears from reading this thread:

http://macos9lives.com/smforum/index.php/topic,566.msg1500.html#msg1500

... member "supernova777" was experiencing similar problems as I have been. Unfortunately there's no posted outcome/resolution in that thread to his difficulties ... which might have been useful ... although the thread does provide some linkage to a question I asked, but never got an answer to:

"How to check the PSU without it being connected to the logic board ?" or "What pin do you jumper Pin 5 to get it to try and turn itself on ?"

Answer: Jumper Pin 5 to (any ?) GND (Duh)

That will be on tonight's menu of activities ... probably along with seeing if I can flash the PC mobo up to the latest version of its BIOS and get W2K to install.

If that all goes well maybe I can get a Mac BIOS flashed into the GeForce 7800 GS ...

Should probably throw this link in as well, as it covers whether (and how) the lack of +25v from PSU is or isn't an issue (it's a mixed bag apparently: doesn't prevent the mobo from functioning generally, but you can forget juice to the Firewire ports, and powering an ADC display of course):

http://forums.applecentral.com/ubbthreads.php/topics/475402/G4_to_ATX_conversion