I've just looked at a Mk 1 that had intermittent power fail problems. Symptoms were that the player would be working fine and then *pow* nothing. Screen out, disks stopped. However, I could contact the player through hyperterm. So it was something to do with the 12V line/power supply.

After a lot of faffing about, I discovered that the two screws for the serial port were slightly loose. This meant that the serial port could move up and down slightly. Since it's soldered to the main board, the main board moves with it. On either side of the serial port is a number of regulator ICs hard mounted with plastic pop rivets to the back of the case. These can also move up and down slightly, hence when the motherboard moves, the regulators moved too.

So what's happening? If the drives move slightly and push down on the daughter board (bump in the car, for example), or the serial port moves while you're upgrading, the leads of the 12V regulator are just long enough to touch the (earthed) lip of the back panel underneath the motherboard, shorting the output of the regulator to 0V.

What you see: screen goes out, stays out, drives spin down.

What you smell: a funny smell of burning as the regulator and the power adaptor heat up.

What you can feel: the back of the case gets BLOODY HOT.

What you do: PANIC! and make a pathetic little squealing sound (similar to a stuck pig) as you try to yank the power plug out.

How to fix the problem.

Take the lid off the player, and remove the drive tray with any drives. Be gentle releasing the cables from the board, there aren't that many left these days.

Unplug the header of the display cable from the motherboard.

Using a Posidrive (not Philips) No. 2 cross head screwdriver, remove the six large screws holding the main board to the case bottom.

Using a PD1, remove the 4 screws at the back of the case holding the case back into the case bottom.

Remove the case back and board together as a unit.It slides backwards out of the case.

Invert the board and look at the clearance between the folded-under lip of the back panel and the protruding leads of the 5 ICs mounted on the back panel. You may see either no, or very little clearance here.

Slightly loosen the two captive hex head screws on the back panel on each side of the serial connector using a 5mm hex socket.

Slide the mainboard up and away from the lip by gripping the serial port and pushing it upwards towards the top edge of the case back, inside it's cutout aperture, away from the lip. This should increase the clearance between the lip and the soldered legs sticking through the mainboard.

With a pair of fine, electronic sidecutters, clip away any excessively long protruding leads ends between the board and the lip making sure you remove the clippings completely to prevent shorts in the future. Don't do more than you need to, just 'cos you think you should - you probably only need to clip off about half a millimetre. Be careful not to damage the PCB or tracking.

Tighten the hex screws on the serial connector, making sure that you are holding the connector up at the top of it's cutout in the case back to maximise the distance between mainboard and lip.

Re-insert the main board assembly and back panel into the case. Replace the 4 rear case screws, and the 6 main board screws. DON'T overtighten and strip/break them. Get them finger tight, and then a gentle, slight twist will lock them.

At this point, if you have access to a hot glue gun, I recommend firstly removing the old Silicone sealant bead originally used to hold the small audio daughterboard in the middle of the main board (the one with a multi-colour ribbon cable attaching it to the main board) and then gluing the board with the rigid-setting hot glue to stop the board wibbling about.

Replace the display header cable, and PLEASE make sure you get it on correctly - not off-by-one-row or off-by-one-pin. It's not difficult on the Mk 1, so just take your time.

At this point, I would suggest you test your unit by applying power to see if the display comes up OK, which will show if you've done the job correctly.

Replace your drives on the sled inside the unit, and tighten the mounting screws. Same rule applies with the drive cables as with the display cable - take your time and get it right. Again, don't overtighten the sled screws. Apply power to check that the drives spin up OK.

Finally, put the lid back on again and make a final check that everything is still functioning.

Thank you, Rob. Copied verbatim into the FAQ.

For the record, though, I don't squeal like a stuck pig. I personally squeal more like a girl scout after you've dropped a spider down her dress.

Also updated a couple of FAQ entries with the capacitor information you gave me. (Interested parties may wish to look at the updated text here.)

I personally squeal more like a girl scout after you've dropped a spider down her dress.

The mind boggles...Just how do you know what that sounds like? I'm beginning to wonder if you should be allowed around children.

Sorry, that was a direct quote from the "blimp" story. I was plagarizing.

A likely story

Sorry, that was a direct quote from the "blimp" story.

I caught your reference Tony. FWIW the next line was something to the effect of "Not that I'd know from personal experience."

I'm still laughing about that story, though.

A likely story

Very unlikely, actually. But still funny as hell:

http://boards.straightdope.com/sdmb/showthread.php?threadid=160851

I remember reading that story, just didn't catch the reference. I'll let you off.

Ah, ok then. I can never remember oblique references like that...Thanks for providing that link again.

Just checked, and mine's just the same

Maybe this explains why I thought my hard drives were failing while I was driving round the the Mini? Perhaps the regulator was shorting very rapidly and making the drives spin down for a split second - causing the "W" to appear during normal operation.