LiteOn PA-6601-1A (600w) blows its TOP

[vsp900]

Re: LiteOn PA-6601-1A (600w) blows its TOP

Oops. I thought they were a stock item at Digikey. I see now that they have zero on hand. Their website still lets you go through the ordering process. I had already added it to my cart but I see not there are none available. Who knows. I may get lucky and they will have it.

Any suggestions on a replacement?

[vsp900]

Re: LiteOn PA-6601-1A (600w) blows its TOP

I actually just ordered several of them from Arrow. I went ahead and ordered the capacitors and a few fuses. Does anyone know which type of fuse I should use? I got some slow blow and some fast blow fuses from them. Q301 was really hard to locate.

I couldn't figure out if the resistors at Arrow were fusible, so I ordered the ones Toast recommended from Digikey.

[godonr]

Re: LiteOn PA-6601-1A (600w) blows its TOP

JF1452... where did you find Q856? I see the marking on the bottom side but no SMD.

vsp900... you have the most common failure I've seen on these G5 supplies. The Q301 > R302 > F1. Interested to see if that fixes it. Are you able to read the short without pulling the MOSFET?
JF1452 has the other failure (TOP) which was the first I encountered.

Has anyone been able to get pinouts on P1, 2 or 3?

[Toasty]

Re: LiteOn PA-6601-1A (600w) blows its TOP

>>Has anyone been able to get pinouts on P1, 2 or 3?<<

Yes



>>I couldn't figure out if the resistors at Arrow were fusible<<

It's not something that's hidden. If it's fusible, it will say so.

Toast

[vsp900]

Re: LiteOn PA-6601-1A (600w) blows its TOP

godon4 - We were able to read the short with the MOSFET attached. Re-checking after the MOSFET was removed, we were able to verify the short across all three pins.

After removing the MOSFET, we replaced the fuse just for giggles and powered up the supply. Before removal, the fuse simply blew. After removal, the fuse didn't blow and some of the pinouts tested correctly. I'm curious to see if the replacement parts fix the problem. With my luck, the TOP will blow next.

Of course, I have a lot more work to do on the liquid cooling system before I put the computer back together. Armed with the writeup on xlr8yourmac.com and a few ideas of my own, this appears to be fairly easy. I already have the processors separated from the LCU. Mine show very little corrosion, so I may be one of the lucky ones.

[vsp900]

Re: LiteOn PA-6601-1A (600w) blows its TOP

I'll add that Digikey shipped out my resistors about an hour after I ordered them. I wish they would have had the MOSFET in stock. I would have ordered those from Arrow as well, but they didn't stock the fusible ones.

Should the fuse be slow blow, timed, or fast blow?

[godonr]

Re: LiteOn PA-6601-1A (600w) blows its TOP

Sounds good. Know MOSFETs can be tricky to read. I have to see about getting some new parts instead of pulling them from other boards. I think you might be OK. The boards I have that blow the TOP have the symptoms JF1452 described. I'm hoping we're looking at 2 fixes here (if I can get him to tell me where the Q856 is). I think the F1 I have is a ceramic slow blow but the markings on it are not standard... don't even see an amp rating. I have to call it a night, but will check back tomorrow to follow your progress. Good luck.

[godonr]

Re: LiteOn PA-6601-1A (600w) blows its TOP

Oops sorry... senior moment. It's a 10A/250v if you can believe the marking right next to it on the board. Duh

[jf1452]

Re: LiteOn PA-6601-1A (600w) blows its TOP

Hi godonr, Q856 is on the underside of the board, it's a small SOT-23 surface mount transistor, my guess is that when the TOP blows, it can cause a surge of voltage to damage the Q856. Also in my case, the surge also damaged OPTO851. I couldn't get the exact repalcement, but it seems fairly standard in specification so I fitted one from my spare parts which had the same pinout.

So after replacing U801, Q856 and OPTO851, I have a fully working PSU.

Hope you have the same luck.

Cheers

Jon Fuge

[godonr]

Re: LiteOn PA-6601-1A (600w) blows its TOP

Early on stj also suggested replacing C852 (47uf/25v) just to be on the safe side. If you hear a "ticking" he said that cap is the cause!

[Toasty]

Re: LiteOn PA-6601-1A (600w) blows its TOP

@ godonr - 2004 PowerMac G5 PSU pinouts

Here:

__________________________________________________

###### Power Supply P1 Connector ######

Pin# Signal Color --------- Pin# Signal Color

1 +5Vstb Purple ----------- 13 GND Black
2 GND Black --------------- 14 Power ON Green
3 FANtach White/Yellow ---- 15 GND Black
4 GND Black --------------- 16 Reserved
5 Reserved ---------------- 17 GND Black
6 GND Black --------------- 18 RTNaud(GND) Black
7 +12Vaud (12V2) Yellow --- 19 GND Black
8 GND Black --------------- 20 +5V sense Red
9 +3.3V sense Orange ------ 21 GND Black
10 GND Black -------------- 22 -12V Blue
11 GND Black -------------- 23 GND Black
12 Reserved --------------- 24 Reserved
__________________________________________________

###### Power Supply P2 Connector ######

Pin# Signal Color --------- Pin# Signal Color

1 +3.3V Orange ------------ 9 +5V Red
2 +3.3V Orange ------------ 10 +5V Red
3 +3.3V Orange ------------ 11 +5V Red
4 +3.3V Orange ------------ 12 +12V3 Yellow
5 Reserved ---------------- 13 +12V3 Yellow
6 +12Vfan Yellow ---------- 14 +12V1 Yellow
7 +12Vfan(12V2) Yellow ---- 15 +12V1 Yellow
8 +25V White -------------- 16 RTNfan(GND) Black
__________________________________________________

###### Power Supply P3 Connector ######

Pin# Signal Color --------- Pin# Signal Color

1 +5V Red ----------------- 5 +5V Red
2 GND Black --------------- 6 GND Black
3 GND Black --------------- 7 GND Black
4 12V2 Yellow ------------- 8 +12V2 Yellow
__________________________________________________

Credits to: dankephoto @ applefritter.com forums

Text file attached for printer.

Toast

[godonr]

Re: LiteOn PA-6601-1A (600w) blows its TOP

Thanks, Toasty. Should a jumper between 14 and 15 turn it on so you can see all the voltages?

[Toasty]

Re: LiteOn PA-6601-1A (600w) blows its TOP

Yes. 14 and any Ground will fire it up. Don't get all frazzled by the 3 connectors/cables. It's nothing more than a "standard" ATX supply with all the different plugs, and a 25v kicker.

I think I saw a mod where one of these was gutted and rewired with an ATX supply board and an external 25v brick. There are also sources for stand-alone SMPS single voltage PSU's for less than $20. Some browsing and creativity you could "make" one of these for less than a broken one is selling for on eBay.

Toast

[godonr]

Re: LiteOn PA-6601-1A (600w) blows its TOP

Toasty... gotta look into that. now that the imac issues have been resolved, I have about 80 G5 towers (unfortunately not all have the PA-6601 ps) I'm nursing to retirement. Even with my connections, that supply from apple goes for almost $300 now. Thanks for suggesting another way to look at it. DR

[godonr]

Re: LiteOn PA-6601-1A (600w) blows its TOP

vsp900 --- just curious --- did the F1 > R302 > Q301/Q302 repair fix your power supply. As for the leak (unbelievable, right), I just got one back that I'd repaired almost two years ago using 2-part epoxy. Best of luck on the repairs.

[vsp900]

Re: LiteOn PA-6601-1A (600w) blows its TOP

godonr -- I've been gone for a week and my parts are just arriving. I got Q301 and the resistors showed up. Still waiting for the caps from Arrow. I'll keep you posted.

toast -- Thanks for the pinouts. That will help us test the supply once we get it "hopefully" fixed.

[vsp900]

Re: LiteOn PA-6601-1A (600w) blows its TOP

Can someone tell me what components "C709" and "C710" are? I have no idea how they got damaged unless they got knocked off moving the board around after I took it apart, but they're somehow gone. I'm sure they're surface mount capacitors, but I'm not sure which ones to get to repair them.

[Toasty]

Re: LiteOn PA-6601-1A (600w) blows its TOP

2 MLCC's next to U704...

No values on those type of caps. You bust 'em, you're toast. No, wait, I'm Toast....

It's so confusing some days

If there is a glue dot and no chip, then it was knocked off.

C709 looks like C708
C710 looks like C712

I would check those 2 caps for value. You may need to pull them, so don't forget they're glued down.

Or, you can follow me down the psychotic path of cutting the trace feeding one side and then measure them...

Toast

[godonr]

Re: LiteOn PA-6601-1A (600w) blows its TOP

vsp900-- did you find out about the caps? I don't have any way to read them (that I know of) but if someone can give me a clue I've got some I can pull. Mine are clearly soldered on the boards.

[vsp900]

Re: LiteOn PA-6601-1A (600w) blows its TOP

I haven't had a chance to desolder them. My friend has some caps of various values, but I'm not sure which ones to use. The best I can do is desolder C708 and C712 as Toast says, but that's still no guarantee that they are the same caps as C709 and C710 that I need.

And it's doubtful that I can test them without desoldering them.

By chance, has anyone used an "Aoyue" brand rework station? I'm looking to buy one. I've also looked at "Blackjack Solderwerks" brand on circuitspecialist.com. I can't afford a professional station.