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#258950 - 24/06/2005 22:23 MKIIa won't power on
Chris Elfers
new poster

Registered: 24/06/2005
Posts: 7
My Empeg was playing music just fine when it became slightly loose and powered down. I pushed it back (this happens sometimes with my particular sled) and it began playing again.

Shortly afterwards, the unit went dead just after I heard a 'shhhhhht' sound in the speakers for 1 second. Now even when I bring it home, I can't power it up. 20GB drive don't spin. And when looking at the motherboard, the red light doesn't go on.

When I apply power, there's a momentary flash of the blue 'link' light on the back of the unit but then nothing. Not even a peep.

What else should I check? Visual inspection of all the components doesn't show anything obvious. I've checked the FAQ and checked continuity of the fuses and they're fine (are there more than 3?).

Visual inspection doesn't show anything strange. I've taken the drive (with cable) and pluged into a spare unit and the drive is fine.

Any help is GREATLY appreciated.

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#258951 - 25/06/2005 02:18 Re: MKIIa won't power on [Re: Chris Elfers]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3584
Loc: Columbus, OH
Check to make sure all of your hard disk screws are still in place. If one of them fell out, it may have shorted something on the mainboard.
_________________________
~ John

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#258952 - 25/06/2005 03:44 Re: MKIIa won't power on [Re: Chris Elfers]
Chris Elfers
new poster

Registered: 24/06/2005
Posts: 7
Nope, no screws or other loose debris. All the wires were undamaged, etc... Other than the brief flash of the blue link light when I plug it in each time, there's no activity. Is there a way the rio can go to sleep and never wake up even if the on/off button pushed and power applied? Maybe resetting the board or something?

Because if it's not that, it seems like the rest of the board isn't getting power since the red led doesn't even light. The power connector seems solid and the same symptom happens if I power thru the sled or via the AC power adapter. Just the brief blue flash.

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#258953 - 25/06/2005 05:59 Re: MKIIa won't power on [Re: Chris Elfers]
mtempsch
pooh-bah

Registered: 02/06/2000
Posts: 1996
Loc: Gothenburg, Sweden
Does it say anything at all on the serial port (capture a boot log)?

)
_________________________
/Michael

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#258954 - 25/06/2005 11:31 Re: MKIIa won't power on [Re: Chris Elfers]
Chris Elfers
new poster

Registered: 24/06/2005
Posts: 7
Nope, not so much as a character in the serial connection (works on spare fine).

When I measure the DC voltage between ground and one of the two exposed pins in the corner by the power adapter, I get 0 volts (this is the pin I've used on another unit for a fan).

When I measure between ground and the power adapter itself, I get 12V (the part that is soldered to the board where the adapter plugs into).

So the failure is after the power plug and before the pin next to the black square component in the same corner as the power. There's a few other parts in that same corner but I'm at a loss as how to check them...

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#258955 - 27/06/2005 16:06 Re: MKIIa won't power on [Re: Chris Elfers]
schofiel
carpal tunnel

Registered: 25/06/1999
Posts: 2993
Loc: Wareham, Dorset, UK
You have a short or failure in one of the power lines on the board. The empeg has a number of jumpers dotted around the board marked variously as: 5V, 3.3V, 5V Analogue, 10V Analogue. Remove them all first. Then replace each voltage jumper one at a time and power on the unit. Check the power LED and the link LED until you find the jumper that makes it fail as it is doing now - it's that voltage line. Let us know here what you find.

Before you do this, remove the drives from the unit. Also, smell the unit to see if there is a burnt smell. Finally, give it a good shake to make sure there are no loose bits in there to make the damage worse (WITHOUT the drives, OK?).
_________________________
One of the few remaining Mk1 owners... #00015

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#258956 - 27/06/2005 17:17 Re: MKIIa won't power on [Re: Chris Elfers]
Chris Elfers
new poster

Registered: 24/06/2005
Posts: 7
I disconnected the drive (pulled out IDE cable too) and gave it a steady shake. Nothing comes loose. No smoke smell even if I leave it on for a while. If the magic smoke was released, it didn't leave behind any discolorations anywhere.

I removed all the jumpers and applied them one-by-one and never got the red LED to come on or any lights on the display.

On my working EMPEG, I notice that if I don't have the 3v jumper, the red LED never comes on regardless of the others. Once the 3V is connected and power applied, the red LED comes on (on the good unit). On the same unit, if I connect either of the blue 5V jumpers, the blue "sleep mode" light goes on in the display.

But nothing like that happens on the dead unit. I can measure 12V when I measure between the round power input and ground. Or when measuring between the light grey metal rectangular component physically touching the 4-pin power connector from the sled (and immediately next to the black cube component). Either of those components measures 12.2V.

Any ideas?

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#258957 - 27/06/2005 18:56 Re: MKIIa won't power on [Re: Chris Elfers]
pca
old hand

Registered: 20/07/1999
Posts: 1102
Loc: UK
Your power supply controller may have died. Remove the jumpers as Rob instructed and measure the voltage between ground and each of the pins of the headers for the 3.3v and 5v rails. Note that one pin of each two-way header is connected to the power supply and should measure the correct supply voltage, and the other pin is connected to the circuitry and should measure nothing.

Also, remove the power and measure continuity between both pins of all the headers and ground. It should be a fairly high resistance, hundreds of ohms up to several K.

If this is all OK, fit the 3V jumper and power it up again. Measure the 3.3V power supply on the jumper if it has an open top (most do). If it's OK, measure the voltage between the pad near the processor labelled VCORE and ground. This should be 1.8V. Be careful not to slip with the probe on this pad and short it to anything. If this is not correct but 3.3V is, the vcore regulator has failed.

pca
_________________________
Experience is what you get just after it would have helped...

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#258958 - 27/06/2005 21:33 Re: MKIIa won't power on [Re: Chris Elfers]
Chris Elfers
new poster

Registered: 24/06/2005
Posts: 7
Thanks for the troubleshooting help everyone! I'm learning a tad bit more about this awesome device. It pains me to see my friend powered down like this. :-)

I only get power on the smaller red jumpers (10V and 5V). Neither the blue 3V or the pair of blue 5V jumpers have any power. No power to the two round components with orange, green, brown dots on them.

I get continuity on the blue pair of 5V jumpers as long as one of them is connected. No continuity on the blue 3V jumper but I don't think there is continuity without power applied.

So it appears, I've lost the 3V and 5V (blue) power.

The power supply controller then?


Edited by Chris Elfers (27/06/2005 21:38)

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#258959 - 28/06/2005 16:41 Re: MKIIa won't power on [Re: Chris Elfers]
pca
old hand

Registered: 20/07/1999
Posts: 1102
Loc: UK
Quote:
I get continuity on the blue pair of 5V jumpers as long as one of them is connected.


Ah. Is this between the pair of pins connected by the jumper, and ground? If you remove the jumpers completely and test between each pin and ground, do you have continuity? If so, my guess is that it's the pins nearest the USB socket?

Assuming yes to the above, this is not good. It means you have a short between the ground rail and the 5v rail. This causes the power supply chip to shut down, killing both 5v and 3.3v.

If this is the case, applying power with the jumpers removed should produce 5v and 3.3v on the relevant headers, on the pins nearest the power supply section. Does it?

pca
_________________________
Experience is what you get just after it would have helped...

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#258960 - 28/06/2005 21:21 Re: MKIIa won't power on [Re: Chris Elfers]
Chris Elfers
new poster

Registered: 24/06/2005
Posts: 7
When I remove all blue jumpers and test continuity between ground and each pin, I get nothing.

But even on an already working unit, that's the case. I assume this is because some sort of power relay which is tripped (not sure).

I can only obtain connectivity if I test between the top-right and bottom-right pins (see exagerated diagram below). Even on the working unit. I can't get continuity by touching ground and any pin -- only when I touch the top-right/bottom-right.

And no continuity between top-left and top-right with all jumpers removed.

On the bad unit, I don't get power on the 5V "rail" on either blue jumper. On the working unit, I do.

Jumper Diagram ('---' character indicates a blue jumper)

O---O
O---O

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#258961 - 29/06/2005 22:38 Re: MKIIa won't power on [Re: Chris Elfers]
JeffreyB
stranger

Registered: 11/05/2002
Posts: 84
Loc: Cincinnati, OH
Quote:
When I remove all blue jumpers and test continuity between ground and each pin, I get nothing.


This is a good thing as it indicates no shorts between the rails and ground. I think you might be getting the term "continuity" mixed up with checking for a voltage being present. What they were asking you to do was check the voltage between each pin of the jumper headers and ground. With the jumpers removed, you should get the proper voltage on one pin (to ground) and nothing on the other if that rail is up and running. If there are no shorts, you should get that same reading even with the jumper reinstalled...

JeffreyB


Edited by JeffreyB (29/06/2005 22:40)

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#258962 - 30/06/2005 20:31 Re: MKIIa won't power on [Re: JeffreyB]
Chris Elfers
new poster

Registered: 24/06/2005
Posts: 7
Ahhh... I'm just dense, sorry.

Nope, no voltage to any pin with jumpers removed. Good unit does show voltage.

So at least there's no short. But could there be a trace on the back that's fried?

At this point, the problem seems somewhat isolated and it's clearly nothing I can do about it. I'll be sending it to Eutronix later to get this puppy in tip-top shape and then I'll see how it goes...

Thanks everyone!

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