Brent thought it might've been the clock wires causing interference but that should now be eliminated.
It's probably not a bad solder join as a) I've been very careful and often checked many of them and b) it sort of seems like the wrong behaviour for that, but of course it still could be!
I took the lid off and it's not cut out yet. More investigation is needed. I wonder if a regulator is getting too warm. Seeking within...
It's probably not a bad solder join as a) I've been very careful and often checked many of them and b) it sort of seems like the wrong behaviour for that, but of course it still could be!
I took the lid off and it's not cut out yet. More investigation is needed. I wonder if a regulator is getting too warm. Seeking within...
Yeah, the regulators are worth a check. I had a CD650 based player that broke the clip that holds the 5V regulator to the large heatsink. The regulator would overheat and its thermal shutdown would kick in, producing the symptoms exactly like what you said (it would appear to stop in the middle of playback, it was actually the player partially resetting as the 5V line went low). It was harder to spot as the regulator actually never burned, though I replaced it when I replaced the clip anyway.
Yep, very goood one.
Anotheridea learned the hard way - check you have at least suficient drop-out voltage across all the regs from input to output. It's usually 3.0v min for lm317/ 7805/7812/7905/7912/7x15ss etc; and especially possibly a bit more, very rarely less for aftermarket regs. ALWSRs for instance need a min. 5.0v due to the onboard pre-regulator, I'd expect similar 5v requirement for alternative regs if they use mosfet pass transistors.
Anyway if this overhead is tight or just under when the player is cold, then it can only take a small change on line voltage (or perhaps a small transformer running warm, or both) for a reg to drop out for regulation as the input voltage drops. That might be enough for something to fall over / the player to reset.
Anotheridea learned the hard way - check you have at least suficient drop-out voltage across all the regs from input to output. It's usually 3.0v min for lm317/ 7805/7812/7905/7912/7x15ss etc; and especially possibly a bit more, very rarely less for aftermarket regs. ALWSRs for instance need a min. 5.0v due to the onboard pre-regulator, I'd expect similar 5v requirement for alternative regs if they use mosfet pass transistors.
Anyway if this overhead is tight or just under when the player is cold, then it can only take a small change on line voltage (or perhaps a small transformer running warm, or both) for a reg to drop out for regulation as the input voltage drops. That might be enough for something to fall over / the player to reset.
Just remembered a follow-up point - when checking the voltage before the reg, use both DC and AC ranges on your meter. These things lie all the time 
You need enough DC voltage, AND for the apparent ripple to be small, so the troughs don't fall out well below the dropout voltage. This will go straight through the reg, feeding the load a much lower and noisier voltage than it appears.
I recently fixed a Naim XPS for a friend where the voltage readings made no sense whatsoever - plenty of DC voltage before a reg outputting 15vdc; connect the player, turn on, and the rail collaped to about 8v after the reg. The regulator tested fine when removed.
When I had the wit to hook-up the scope it became clear the raw rail had massive 100Hz ripple, infact the it was just the half-wave rectified sine returning to 0v 100times a second (the associated 10000uF reservoir cap had gone open-circuit inside the can after a nearby lightening strike). But the DVM still happily reported 22Vdc input, 15VDC output from the reg...
You need enough DC voltage, AND for the apparent ripple to be small, so the troughs don't fall out well below the dropout voltage. This will go straight through the reg, feeding the load a much lower and noisier voltage than it appears.I recently fixed a Naim XPS for a friend where the voltage readings made no sense whatsoever - plenty of DC voltage before a reg outputting 15vdc; connect the player, turn on, and the rail collaped to about 8v after the reg. The regulator tested fine when removed.
When I had the wit to hook-up the scope it became clear the raw rail had massive 100Hz ripple, infact the it was just the half-wave rectified sine returning to 0v 100times a second (the associated 10000uF reservoir cap had gone open-circuit inside the can after a nearby lightening strike). But the DVM still happily reported 22Vdc input, 15VDC output from the reg...
More things to check there then
If you have any ideas specifically related to warmth that would be much appreciated. The player is extremely consistent in its behaviour now. It plays for about 40mins then dies. If I turn it off to cool down / "rest" it then works again for a while till it warms up / "gets tired".
Once it has warmed up and "crashed" pressing play will only get it moving for a few seconds before it shuts down / resets again. Based on this it's surely temperature-related, but that could be regs, caps, mechanism grease, ceramic caps(??) etc.
If you have any ideas specifically related to warmth that would be much appreciated. The player is extremely consistent in its behaviour now. It plays for about 40mins then dies. If I turn it off to cool down / "rest" it then works again for a while till it warms up / "gets tired".
Once it has warmed up and "crashed" pressing play will only get it moving for a few seconds before it shuts down / resets again. Based on this it's surely temperature-related, but that could be regs, caps, mechanism grease, ceramic caps(??) etc.
Slightly off topic update
Excuse a slightly off topic moment. I too have sidelined my Alpha for a bit. Recall in my case I messed up the main board and the balance ended up as a USB/1541a/tube dac. The PCM2706 USB died. No, that's good news as I wanted to upgrade to asyncronous USB. Have ordered an XMOS based board from a cool guy on this site. The interesting thing is it will enable me to play high res content on the Arcam audio board. 24/192 will be possible. I know the 1541a is only 16 bit, but it will apparently ignores the extra bits and sounds great. Should be interesting to hear.
This has spawned a couple of projects.
USB2 is best supported in Unix, so I am dabbling in those waters toying with a dedicated Alix processor that picks music off a netserver and passes it to the USB. Easy to build power supply and may even fit in the arcam box. Very cool, but complicated.
Meanwhile, I messed with my backup CD to the point of destroying it. So last night went looking for a new Alpha and tripped over a Rotel 855 for sale in my home town. Its the real deal, German engineered, 1541A N2 chip & Blackgate caps for $100! With just a power cord swap to take conditioned power, its rivalling my earlier efforts. I plan to take our best learnings from this site and like Andrew take my time this time. Who knows where that will end up. I must say I am addicted to the 1541a
I am enjoying a quiet new years eve at home with my wife, fine food, German beer and fine music. All the best for a happy and safe new year.
Excuse a slightly off topic moment. I too have sidelined my Alpha for a bit. Recall in my case I messed up the main board and the balance ended up as a USB/1541a/tube dac. The PCM2706 USB died. No, that's good news as I wanted to upgrade to asyncronous USB. Have ordered an XMOS based board from a cool guy on this site. The interesting thing is it will enable me to play high res content on the Arcam audio board. 24/192 will be possible. I know the 1541a is only 16 bit, but it will apparently ignores the extra bits and sounds great. Should be interesting to hear.
This has spawned a couple of projects.
USB2 is best supported in Unix, so I am dabbling in those waters toying with a dedicated Alix processor that picks music off a netserver and passes it to the USB. Easy to build power supply and may even fit in the arcam box. Very cool, but complicated.
Meanwhile, I messed with my backup CD to the point of destroying it.
So last night went looking for a new Alpha and tripped over a Rotel 855 for sale in my home town. Its the real deal, German engineered, 1541A N2 chip & Blackgate caps for $100! With just a power cord swap to take conditioned power, its rivalling my earlier efforts. I plan to take our best learnings from this site and like Andrew take my time this time. Who knows where that will end up. I must say I am addicted to the 1541aI am enjoying a quiet new years eve at home with my wife, fine food, German beer and fine music. All the best for a happy and safe new year.
It stutters and then stops just as if the stop button had been pressed. The display shows the TOC. If you press play it will fail very quickly in exactly the same manner.
Happy New Year everyone
That's exactly what mine was doing. I'd have at look at what the mainboard's +5V rail is doing once the player has warmed up. I'd also check on the temperature of the mainboard's 7805 regulator and make sure it's still well mounted to its heatsink. If it's a 78M05 type (the medium power version) I'd replace it with a 7805.
If that doesn't turn up anything of interest, maybe it's time to get a can of freezer spray and see if cooling anything has any effect.
If that doesn't turn up anything of interest, maybe it's time to get a can of freezer spray and see if cooling anything has any effect.
Hi Simon,
Don't want to be a doomsayer
I had a similar problem once, turned out to be the 1541. It was easy for me to check as I had a spare chip and it was on a socket. Once the new chip was in I never had the problem again.Regards
Pete
Main board grounding
New topic :
On the Phillips main board I, like everyone else who have them, have several factory made solder blobs on link wires that act as grounds - which are pretty handy.
Being that they are all effectively soldered ( connected ) to the copper cladding on the surface can I just create my own anywhere I please ?
This is purely for my own convenience as I decide where to put my regs - in an effort to get them as close as possible to the receivers.
Am I wrong in assuming I can just add solder to it and use that new point or must I connect to ground at the nearest available original solder blob ?
Thanks
New topic :
On the Phillips main board I, like everyone else who have them, have several factory made solder blobs on link wires that act as grounds - which are pretty handy.
Being that they are all effectively soldered ( connected ) to the copper cladding on the surface can I just create my own anywhere I please ?
This is purely for my own convenience as I decide where to put my regs - in an effort to get them as close as possible to the receivers.
Am I wrong in assuming I can just add solder to it and use that new point or must I connect to ground at the nearest available original solder blob ?
Thanks
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