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#1 2014-05-29 20:54:36

uniserver
Member
From: Sf, Mi
Registered: 2014-05-15
Posts: 956
Website

Is your LC I / LCII / LCIII / 475/Q605 TDK PSU Dead?

Here is the common fix for these Power Supplies

There is 4 Caps that go bad, 90% of the time change these Caps,  Clean up leaked cap goo with some q-tips + acetone
and your back in business!

C53 − 25v 470uf
C54 − 25v 470uf
C56 − 25v 56uf
C64 − 10v 270uf

http://maccaps.com/MacCaps/Capacitor_Re … rence.html
lcpsu1.jpg

Last edited by uniserver (2014-05-29 20:58:38)


#I Re-Cap √Mac √NeTX √Amiga Boards - A/B - PSU# (MacCaps.com)  Modern SCSI HD's - For Old Macs - Pre Cfg'd - 10k RPM! 73gb!! $50 + free shipping  -- Mac 128K Re-Ram kits (16 Chips) $35 + shipping, Floppy Issues?-> Bourns Filter Solution 128k - SE/30, $16 + shipping

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#2 2015-07-07 15:21:48

Elfen
Member
From: NYC, NY
Registered: 2015-07-07
Posts: 20

Re: Is your LC I / LCII / LCIII / 475/Q605 TDK PSU Dead?

Thread necromancy!

I would be one of the first to say that the recapping does indeed work on these power supplies. But it is without problems.

These caps come in many different physical sizes, which created an issue when I did it. The caps I received from Mouser and Newark, were physically fatter than the ones in the PSU. In re-reading the caps, I noticed that some of them were labeled different sizes. So back then, I measured the caps in question and determined that the proper physical size was available, but stupid me threw out the old caps and the notes of their physical dimensions.

Because of the size differences, some caps on the board needed to be leaned away from the replacement caps to fit, a couple of caps had to stand above the others to fit in the board and one of the two leans directly on the PSU wall. Put a piece of duct tape to add insulation against the cap, though the cap's plastic wrapper would be enough to protect it, more protection is better. It took some doing but I got the PSU back together and it is running in a LCIII beautifully.

Though this particular LCIII needed a recap, it was still running iffy though it ran a lot better than before. By that I mean, odd crashes, slow boot times and for some reason dim screen (probably low output from the video port?). With the recap on the PSU, things run faster and better, the LC has not crashed once and the screen comes up faster and brighter! All this is simple to explain, with a cleaner output from the PSU, the LCIII behaved a lot better.

Last edited by Elfen (2015-07-07 15:22:29)

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#3 2015-07-07 18:51:39

uniserver
Member
From: Sf, Mi
Registered: 2014-05-15
Posts: 956
Website

Re: Is your LC I / LCII / LCIII / 475/Q605 TDK PSU Dead?

Yup and as Elfen has mentioned before, its good to change all the caps in the picture as well...  All though the 4 specifics mentioned are usually completely blew out wasted.  if you change them all in the picture, its probably the best solution.  I believe those other 3 caps there are 1000uf 16v,  changing them with 1000uf 35v would be a nice upgrade.     Nice that you could make it over Elfen.      and these threads were started to be re-visited at any time...  no problems what so ever... We can always make improvements to our vintage mac's and processes.   Were kind of writing the book as we go.  :-)


#I Re-Cap √Mac √NeTX √Amiga Boards - A/B - PSU# (MacCaps.com)  Modern SCSI HD's - For Old Macs - Pre Cfg'd - 10k RPM! 73gb!! $50 + free shipping  -- Mac 128K Re-Ram kits (16 Chips) $35 + shipping, Floppy Issues?-> Bourns Filter Solution 128k - SE/30, $16 + shipping

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#4 2015-07-07 21:26:28

mcdermd
Member
From: Corvallis, OR
Registered: 2014-05-12
Posts: 970
Website

Re: Is your LC I / LCII / LCIII / 475/Q605 TDK PSU Dead?

I think we're all for thread necromancy here. We'd rather have a lot of info in one thread than small bits of info in many threads.


Daily Drivers: 27" iMac 2.8 GHz Quad-Core i7 (Late 2009), 21.5" iMac 2.7GHz Quad-Core i5 (Late 2013), 11" Macbook Air 1.6 GHz i5 (Mid-2011)
See the restored heroes here.

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#5 2015-10-24 04:52:52

Schmoburger
Member
From: Australia
Registered: 2015-04-21
Posts: 281
Website

Re: Is your LC I / LCII / LCIII / 475/Q605 TDK PSU Dead?

mcdermd wrote:

I think we're all for thread necromancy here. We'd rather have a lot of info in one thread than small bits of info in many threads.

Here here! Old threads are good threads!


Stay hungry... Stay foolish.
G5 2.0DC, Yikes G4/500 Sonnet-Enhanced, B+W G3/450, 9600/200MP, 7600/200, iMacs DVSE Graphite and 600 Snow, 7220/200, WGS 7350/180, 6360/160, 5500/250 DE, Pismo, 2x Lombards, 6100/66DOS, 2x CC's, 3x Pluses, 512K, SE/30, SE Superdrive, 2x Classics, IIvx, IIci, IIsi, 3x LC520, 4x LC575, 5x P580, LC, LCIII, //gs LE, 2x ROM 02 //gs', IIe... and I'm outta characters!

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#6 2016-04-28 03:45:12

Dnal
Member
Registered: 2015-01-03
Posts: 58

Re: Is your LC I / LCII / LCIII / 475/Q605 TDK PSU Dead?

It looks like the pic is a TDK.  I just got my LCII recapped and it worked great for about 5-10 minutes, then the PSU crapped out.  And my spare is showing 0V on all rails (might be a fuse on that one).  Both of these are Astec and it looks like all Nich caps in them.  There is also a gigando cap in the middle.  Do I need to replace that too or just the surrounding ones?

Last edited by Dnal (2016-04-28 11:06:25)

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#7 2016-05-01 17:53:42

bbraun
Member
Registered: 2014-05-29
Posts: 1,064
Website

Re: Is your LC I / LCII / LCIII / 475/Q605 TDK PSU Dead?

Generally speaking, the large ones tend to survive the longest, so you might not need to replace it right now.  But if you're making an order and doing all the work to replace the rest, you might want to do that one too anyway.

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