Author Topic: Mac Mini bricked? No video, black screen.  (Read 2831 times)

Offline ssp3

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Mac Mini bricked? No video, black screen.
« on: August 17, 2023, 07:01:07 AM »
I was fiddling with my Mac Mini yesterday, testing all newly arrived SATA-ATA adapters, various drive and adapter combinations, when suddenly, after being disconnected from mains for a few hours, on a next attempt to boot, my Mini stopped producing any video and I was greeted with black screen and 'No signal' banner on a monitor. (Sony TV, connected via DVI-HDMI adapter).

My Mini is in some sort of a coma now. Symptoms are somewhat similar to those described in these two threads:
Mac mini G4 1.42 boots to black screen.
http://macos9lives.com/smforum/index.php?topic=6286.0
Bricked iMac With Open Firmware Commands (and how I fixed it)
http://macos9lives.com/smforum/index.php?topic=2138.0

I've tried every possible ritual known to me, but nothing has changed. We are brain dead now  :(

Battery measures 3,2 Volts.
Starting without a battery - no change.
Pressing Cuda switch on the motherboard - no change.
Re-seating RAM - no change.
There is start-up chime.
The LED on the front is lit.
On startup, the fan spins at high-ish speed and then slows down, as before.
With RAM removed there is one short beep.
When pressing and holding power button at startup, there is one long beep, followed by a blinking LED, followed by a chime.
With or without internal drive or optical drive - no change.
Optical drive, if installed, produces "eject noise" at startup.
Logitech USB mouse does not light up.
cmd+opt+P+R does not work.
cmd+opt+O+F does not work.
Can not enter target mode - Mini is not seen either by PB G4 or MBP over FireWire.
Can not start from external FireWire drive.
Can not boot from Ross' v9 CD.
Does not respond to mouse / keyboard.
Connecting Mini to Dell U2412 (1920x1200) monitor by DVI cable - still no video.
Ritual suggested by iMic in his thread (hitting enter key as rapidly as possible) - no change.

Some unusual behaviour:

Pressing and holding power button, while plugging in the power cable, as per Service Manual, does not start the machine.

Prior to falling into coma. Stuff that I didn't pay particular attention to:

Despite having fresh battery, it never retained its Date and Time if disconnected from mains even for a short period.
Yesterday, on several occasions, while testing adapters, the Mini booted up normally, but the fan was not spinning. After forced shutdown by power button and on the next boot the fan spun up normally.
Now and then it would take a long-ish period of time for desktop icons to appear. That was with various drives/adapters. I can't remember exactly with which.

I did pull the power cable instead of forcing shutdown with power button on several occasions, especially lately.
Also, in OpenFirmware, I did issue reset-nvram and reset-all commands a few times, but nothing else.


Any ideas what else I could try?


« Last Edit: August 17, 2023, 07:58:00 AM by ssp3 »
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Offline FBz

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Re: Mac Mini bricked? No video, black screen.
« Reply #1 on: August 17, 2023, 08:24:57 AM »
"I'm taking back what I said about Mac Mini and write speed drops a few posts back.” -ssp3

Is this the same Mini mentioned above, that was giving you varying results during previous tests?

I’d return the thing back to its’ original setup state / configs (as near as possible) checking all wires and connections and then attempt to boot from a Tiger installer CD (or an original G4 Mac mini installer disc).

The MCA004 v1.3 adapter bridges in the minis here would often require this approach after failed boots, partial boots and even complete lock-ups and screen freezes during various moments of the boot process.

AND… odd as it may seem, check that your 44 pins of whatever adapter you are using ARE properly connected / aligned.  I have “mis-connected” (by top and bottom rows of pins AND left and right orientations) before. So check, and/or maybe change the adapter that you’re currently using to a previous one.

There’s also the possibilities that something has not been properly re-connected elsewhere - OR has come loose during all of the various testing. AND also (hopefully not)… that your mini has basically “given up” the proverbial “ghost”.

ALL minis here are thoroughly cleaned, dusted and ALWAYS, always… new heatsink paste applied.

What sort of exhaust temperatures have you recently noted, when it was working?

AND what power brick are you using… 85 Watt or the 110 Watt?

*Whenever I’ve had to pull the power cable to recover a frozen mini, I always zap PRAM and rebuild the DT afterwards.
Failure to retain Date & Time however (even with a fresh battery) - leads me to question: (1). connections and (2). failing CPU health.

Hope that you can recover the thing.

If condition persists, leave the thing powered up (even with a black screen, no-boot state) and measure temperature of the mini’s bottom after 1 minute and then after 10-15 minutes. Check the exhaust temp at same intervals too.

Offline ssp3

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Re: Mac Mini bricked? No video, black screen.
« Reply #2 on: August 17, 2023, 10:14:15 AM »
Is this the same Mini mentioned above, that was giving you varying results during previous tests?
Yes, my only one. (But, btw, the results were consistent. I just got mislead by one particular drive).
Quote
I’d return the thing back to its’ original setup state / configs (as near as possible) checking all wires and connections ..
All wires are OK. Besides, there aren't that many in Mini. I had Mezzanine and modem boards removed at the time of the incident, but now the Mezzanine is back in its place and there is no change
Quote
.. and then attempt to boot from a Tiger installer CD (or an original G4 Mac mini installer disc).
I haven't tried the Tiger Installer CD yet (I don't have one). I might try that next, but the CD drive now have swallowed my Ross' Mac Mini Install CD v9 and is not giving it back.
Quote
The MCA004 v1.3 adapter bridges in the minis here would often require this approach after failed boots, partial boots and even complete lock-ups and screen freezes during various moments of the boot process.
The Mini went south with red Marvell and IDE CD caddy to SATA adapters in place - see http://macos9lives.com/smforum/index.php/topic,6808.msg52194.html#msg52194
Quote
AND also (hopefully not)… that your mini has basically “given up” the proverbial “ghost”.
For the time being it is a ghost.
Quote
What sort of exhaust temperatures have you recently noted, when it was working?
Nothing unusual. Comfortably warm, I would say. But, IIRC, I had an impression that the fan ran faster than before with two SSDs in place.
Quote
AND what power brick are you using… 85 Watt or the 110 Watt?
85Watt
Quote
If condition persists, leave the thing powered up (even with a black screen, no-boot state) and measure temperature of the mini’s bottom after 1 minute and then after 10-15 minutes. Check the exhaust temp at same intervals too.
Now that I have acquired thermometer that can measure surface temperatures (to test the SSD controller, adapter voltage regulator and other chip temps) I can do that. I'll post the results later today.
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Offline ssp3

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Re: Mac Mini bricked? No video, black screen.
« Reply #3 on: August 17, 2023, 09:30:13 PM »
Mac Mini G4 1.42 in coma. All parts, except modem board installed. 1GB RAM. "Red" Delock Marvell adapter, 128GB Samsung mSATA drive.
Still black screen, still "No signal".
Here are the temperatures.

1 min. bottom: 30ºC / 86ºF
4 min. bottom: 38ºC / 100ºF
15 min. botom: 41-42ºC, hottest spot under processor: 45ºC / 113ºF
Hottest spot at exhaust: 47ºC / 117ºF

The numbers look OK to me.

Measured with this thing.
« Last Edit: August 18, 2023, 06:44:09 AM by ssp3 »
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Offline ssp3

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Re: Mac Mini bricked? No video, black screen.
« Reply #4 on: August 18, 2023, 12:00:13 AM »
Of course, another possibility could have been that I've killed the Mini by experimenting with my new chinese IDE CD caddy to SATA SSD adapter, although I find it highly unlikely.
I never hot plug anything and I have never ever killed any Mac or SCSI card in all those years, while experimenting with drives and their settings.
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Offline FBz

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Re: Mac Mini bricked? No video, black screen.
« Reply #5 on: August 18, 2023, 06:13:56 AM »
Temps seem to be within acceptable, normal range.
Compared to similar running temps of a 1.5 GHz mini here yesterday.

I’d try returning it all to “original” configuration.
Still have the original spinning HDD?

And isn’t it a bit odd that the MCA004 & AS331 adapter bridges
(not jumpered = “Master”) work in conjunction with original CD
drives… in Mac minis that supposedly require Cable Select?
As, the same adapter bridges also work un-jumpered in MDDs
and Quicksilvers (solo) without changing anything with their ODs.

BUT if the mini’s CD/DVD drive IS on the same bus…
perhaps therein lies the rub.

Hopefully the thing will function when returned to original configs
& then attempt adding the Chinese IDE CD caddy back afterwards.

Fingers crossed here.

Offline ssp3

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Re: Mac Mini bricked? No video, black screen.
« Reply #6 on: August 18, 2023, 07:15:04 AM »
I’d try returning it all to “original” configuration.
Still have the original spinning HDD?

It is "all original" sans modem board and spinning HDD. I got my Mini without any drive. I do have some HDDs pulled from Powerbooks, though.

Quote
And isn’t it a bit odd that the MCA004 & AS331 adapter bridges
(not jumpered = “Master”) work in conjunction with original CD
drives… in Mac minis that supposedly require Cable Select?

I remember reading somewhere that the CD/DVD drive in Mini is factory configured as Device 1 (slave) with Cable Select, whatever that means. That would correspond to the configuration on the left.




I assume, the Cable Select is set somewhere on the motherboard or on a so called Interconnect Board.
It all works fine as DVD and HDD (SSD) combo, but, if you put a chinese JMicron 20330 or "IDE/SATA DOF" chip based adapters, which support master/slave configuration but not cable select (as per datasheet) and are mostly configured as master by the manufacturer, in place of DVD drive, you mess up all settings.
The only way to make the 2 drive configuration to work in Mac Mini is to put an adapter that supports Cable Select and is set so in place of original HDD. Unfortunately, only "red" Marvell based adapters have that option.

Quote
BUT if the mini’s CD/DVD drive IS on the same bus…
perhaps therein lies the rub.

It IS on the same bus.



« Last Edit: August 18, 2023, 08:52:24 AM by ssp3 »
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Offline ssp3

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Re: Mac Mini bricked? No video, black screen.
« Reply #7 on: August 30, 2023, 07:00:33 PM »
After reading this thread over at MacRumours
https://forums.macrumors.com/threads/mac-mini-g4-will-not-output-to-hdmi-via-dvi.2206219/
and especially this one post by 'Bug-Creator'
Quote
A few facts/experiences:
.....
- the digital part of the video output has a relativ high failure rate (still not sure wether that 1920x1200 monitor killed DVI on my Mini or the other way round :oops: ) Know of at least 2 Mini having the same issue (without ever going to or beyond FullHD)

I bought a DVI to VGA adapter to check whether the analog part of the video output is still alive. Sadly, no. Same result as before - black screen.

With great sadness I herewith declare my 1.42GHz Mac Mini G4 as KIA.
All while testing chinese adapters for the benefit of Mac Mini G4 tweakers society.
RIP, my friend.
It leaves Power Supply and lonely 1GB RAM stick behind.
 :(
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Offline DieHard

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Re: Mac Mini bricked? No video, black screen.
« Reply #8 on: August 31, 2023, 03:36:39 PM »
Quote
With great sadness I herewith declare my 1.42GHz Mac Mini G4 as KIA.
All while testing chinese adapters for the benefit of Mac Mini G4 tweakers society.

Even knowing the risks of such crazy innovations, it is still sad that it gave its life to science... a moment of silence is in order  :'( :'( :'(