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#1 2016-06-18 15:56:52

ClassicHasClass
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From: Electron Alley
Registered: 2014-05-26
Posts: 1,081
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thule (Mac IIci) blows another logic board

thule, the NetBSD IIci that handles the internal network, went unresponsive yesterday and wouldn't power up. Eventually I determined the logic board was faulty and just swapped everything into a spare system. So that's back and running.

Meanwhile, this logic board has a curious fault: if it sits for a long time (several minutes or more), it will power on. Otherwise it is completely inert. The same power supply works fine in the new spare unit.

Anyone seen this failure mode? It sounds vaguely familiar. This unit was a uniserver recap, so I'm pretty sure that's not it.

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#2 2016-06-18 22:16:07

macdrone
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From: Rainier, Or
Registered: 2014-05-25
Posts: 219

Re: thule (Mac IIci) blows another logic board

bad trace maybe finally rot through?

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#3 2016-06-18 22:45:21

LazarusNine
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From: UK
Registered: 2015-03-07
Posts: 62
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Re: thule (Mac IIci) blows another logic board

Goodness. I had a similar problem with a Quadra 700 - very similar symptoms. I took the machine apart a bunch of times and put it back together. It seemed to only boot sporadically and, as you describe, only after sitting for a while. In my case, I SUSPECT it was the RAM. The machine suddenly started working more regularly after swapping a bunch of new and different SIMMS in and out. That said, I haven't booted it in ages. It's entirely possible it's on the fritz again. All the best in sourcing a solution.

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#4 2016-06-19 05:57:39

uniserver
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From: Sf, Mi
Registered: 2014-05-15
Posts: 954
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Re: thule (Mac IIci) blows another logic board

yeah short pin 9 and 10 under the logic board... and that will bypass all the rotted up bullshit that controls the soft power.  it will just be on.


#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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#5 2016-06-19 06:02:08

uniserver
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From: Sf, Mi
Registered: 2014-05-15
Posts: 954
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Re: thule (Mac IIci) blows another logic board

macIIcisch.GIF


#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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#6 2016-06-19 16:50:36

ClassicHasClass
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From: Electron Alley
Registered: 2014-05-26
Posts: 1,081
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Re: thule (Mac IIci) blows another logic board

uniserver wrote:

yeah short pin 9 and 10 under the logic board... and that will bypass all the rotted up bullshit that controls the soft power.  it will just be on.

Which pin is that? Where are they located?

This system runs 24/7, so it can just stay on.

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#7 2016-06-23 11:14:46

uniserver
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From: Sf, Mi
Registered: 2014-05-15
Posts: 954
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Re: thule (Mac IIci) blows another logic board

pin 9 and 10 under the mainboard on the through hole power connector.

solder bridge those bad boys and your on.


#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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#8 2016-06-23 15:03:00

ClassicHasClass
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From: Electron Alley
Registered: 2014-05-26
Posts: 1,081
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Re: thule (Mac IIci) blows another logic board

Okay, I'll warm up the soldering iron this weekend. smile

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#9 2016-06-23 17:42:56

uniserver
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From: Sf, Mi
Registered: 2014-05-15
Posts: 954
Website

Re: thule (Mac IIci) blows another logic board

Sounds good. and if you want to still control the on off, you can use a power strip.


#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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#10 2016-06-24 05:34:51

ClassicHasClass
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From: Electron Alley
Registered: 2014-05-26
Posts: 1,081
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Re: thule (Mac IIci) blows another logic board

I've actually got a remote control power switch, but seriously, the system runs 24/7.

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