I was repairing a NAD C390DD for my friend and tough I'll post the solution here too as this type of problem is likely to happen on other units and I did not find it documented in web prior to this.
Symptoms before fix
A) When powering on from back panel power button the orange 'sleep LED' comes on
B) After push of the on/standby button on front panel 1 click of a relay can be heard and the orange led turns blue ... display will so no sign of life. Not other relay clicks follow. The unit does not switch on.
Problem appeared to be in secondary PSU which supplies the +5V and after switch on the +12.5V.
The +12.5V power line showed only +4.5V after the step B. So clearly something wrong. Anyhow, longish troubleshooting later it turned out to be a fault in following capacitors.
Hope this helps someone in future.
Symptoms before fix
A) When powering on from back panel power button the orange 'sleep LED' comes on
B) After push of the on/standby button on front panel 1 click of a relay can be heard and the orange led turns blue ... display will so no sign of life. Not other relay clicks follow. The unit does not switch on.
Problem appeared to be in secondary PSU which supplies the +5V and after switch on the +12.5V.
The +12.5V power line showed only +4.5V after the step B. So clearly something wrong. Anyhow, longish troubleshooting later it turned out to be a fault in following capacitors.
Hope this helps someone in future.
Attachments
Good work, Ergo
Have you or anyone got the power up sequencing of the various boards in the C390DD? I notice various power sensing signals that control the relays for 12.25V 5V & +/-70V supplies.
I ask because I'm looking at some experiments on better quality PSes but didn't want to get the sequencing wrong & damage/detroy boards
Have you or anyone got the power up sequencing of the various boards in the C390DD? I notice various power sensing signals that control the relays for 12.25V 5V & +/-70V supplies.
I ask because I'm looking at some experiments on better quality PSes but didn't want to get the sequencing wrong & damage/detroy boards
Hi Ergo,
Thank you so much for reporting this. I have heard of one or two people having this issue and they ended up getting the whole PSU-B assembly replaced under warranty. Warranty is not an option for a lot of owners now though so this is great info to have.
I don't have any functional issues yet with my C390DD, but last time I opened it I noticed some of the capacitors are starting to bulge. So I expect it is only a matter of time before something goes wrong.
Particularly the bigger green capacitor C212 on PSU-B was bulging at the top on mine.
That is not one of the capacitors you changed so that would be an extra one to add to my list of ones to change.
I don't know if this is the place to ask for advice, but I will try. I only have experience with tin lead solder (and minimal experience at that) - never done anything with lead free which I assume the C390DD uses.
When people repair modern lead free solder equipment, do they have to find out which lead free alloy was used so they can use the same, or can they use any lead free variety, or is it fine to just use tin lead solder to repair these? I have no idea how to find out what alloy solder was used in the C390DD.
Which solder alloy/mix did you use?
If I have to use lead free solder, I will have some learning and practice to do and I will likely need new tools. Not a bad thing I suppose.
Anthony
Thank you so much for reporting this. I have heard of one or two people having this issue and they ended up getting the whole PSU-B assembly replaced under warranty. Warranty is not an option for a lot of owners now though so this is great info to have.
I don't have any functional issues yet with my C390DD, but last time I opened it I noticed some of the capacitors are starting to bulge. So I expect it is only a matter of time before something goes wrong.
Particularly the bigger green capacitor C212 on PSU-B was bulging at the top on mine.
That is not one of the capacitors you changed so that would be an extra one to add to my list of ones to change.
I don't know if this is the place to ask for advice, but I will try. I only have experience with tin lead solder (and minimal experience at that) - never done anything with lead free which I assume the C390DD uses.
When people repair modern lead free solder equipment, do they have to find out which lead free alloy was used so they can use the same, or can they use any lead free variety, or is it fine to just use tin lead solder to repair these? I have no idea how to find out what alloy solder was used in the C390DD.
Which solder alloy/mix did you use?
If I have to use lead free solder, I will have some learning and practice to do and I will likely need new tools. Not a bad thing I suppose.
Anthony
Bog standard 60-40 or 63-37 tin-lead solder is fine. If anything, it'll be better in the long term anyway.
Gotta "love" how, instead of improving recycling practices, international authorities just went with the "shotgun approach" and banned leaded solder. Because reasons...
The internet's full of all the down-sides of lead-free, not in the least due to its ~30C higher melting temperature.
Either way, for small-scale manual soldering like this, for personal use, don't sweat it and go with the time-proven and headache-less leaded stuff.
Gotta "love" how, instead of improving recycling practices, international authorities just went with the "shotgun approach" and banned leaded solder. Because reasons...
The internet's full of all the down-sides of lead-free, not in the least due to its ~30C higher melting temperature.
Either way, for small-scale manual soldering like this, for personal use, don't sweat it and go with the time-proven and headache-less leaded stuff.
Thanks Khron.
I guess the issue I was concerned about was if it was an issue to mix for example 60-40 tin-lead (and related flux) with the remnants of the mystery lead-free solder alloy that would still be on the board after I remove the faulty components. Example issue I am thinking of is hidden cold solder joint. From what you are saying it seems that it is not a concern. Thanks for letting me know.
Anthony
I guess the issue I was concerned about was if it was an issue to mix for example 60-40 tin-lead (and related flux) with the remnants of the mystery lead-free solder alloy that would still be on the board after I remove the faulty components. Example issue I am thinking of is hidden cold solder joint. From what you are saying it seems that it is not a concern. Thanks for letting me know.
Anthony
http://publications.npl.co.uk/npl_web/pdf/matc85.pdf
This is from 16 years ago, but one of the conclusions is pretty clear:
"Mixed alloy joints in this study generally gave better or equal first failure performance relative to the original alloys."
Risks of Mixing Tin-lead and Lead-free
This is from 16 years ago, but one of the conclusions is pretty clear:
"Mixed alloy joints in this study generally gave better or equal first failure performance relative to the original alloys."
Risks of Mixing Tin-lead and Lead-free
Thanks a million
@ergo
Thanks a million for this, I'm suffering with this problem for a year now.
The C390DD went for a repair last year, but problem was never resolved.
Sometimes the C390DD boots up in one go, sometimes I have to retry for a few times (2-10) before the C390DD starts up.
I'll order the capacitors right now, will do a replace somewhere next week.
Thanks again,
Wim
@ergo
Thanks a million for this, I'm suffering with this problem for a year now.
The C390DD went for a repair last year, but problem was never resolved.
Sometimes the C390DD boots up in one go, sometimes I have to retry for a few times (2-10) before the C390DD starts up.
I'll order the capacitors right now, will do a replace somewhere next week.
Thanks again,
Wim
What you does the cd263(x) mean? I bought these. Are they the right ones?
https://www.mouser.com/datasheet/2/315/RDF0000C1260-1391675.pdf
"CD263" kinda-sorta reminds me of markings i've seen on some no-name electrolytics in several cheap devices.
Those Panasonic FP's should do the job nicely, though.
Edit: Might've found something about CD263(X).
http://www.jianghaius.com/PDF/CD263-1.pdf
http://www.jianghaius.com/PDF/CD263-2.pdf
Dunno about you, but i'd take all those specs with a bucketload of salt...
Those Panasonic FP's should do the job nicely, though.
Edit: Might've found something about CD263(X).
http://www.jianghaius.com/PDF/CD263-1.pdf
http://www.jianghaius.com/PDF/CD263-2.pdf
Dunno about you, but i'd take all those specs with a bucketload of salt...
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