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Message |
jakdedert
Guest
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 Posted:
Thu Feb 10, 2005 12:17 am Post subject:
Re: Are You Tim from Emu? |
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Tim Schwartz wrote:
| Quote: | Hello,
As I don't have any idea who Emu is, I'm not Tim from Emu.
Methinks he doth protest.... |
<G>
jak
| Quote: | Regards,
Tim Schwartz
Bristol Electronics
True american Zero wrote:
Are you Tim from Emu ?
In article <4208C010.D6CB7409@worldnet.att.net>, Tim Schwartz
toschwartz@worldnet.att.net> wrote:
Hello,
While I'm not sure that this is the answer, there is a service note
about "CD will not read in, CD is spinning on high speed." from NAD
for the 522.
Cause: 5V to the RF amp/laser is too low; D505 is defective,
regulator U506 (78L05A) can also be defective.
Solution: Replace D505, zener 4.3V, 0.5W with 3.3V 1.3W type.
Replace the regulator U506 from 78L05A (TO-92 case) by a 7805 in a
TO-220 case (MC78M05 or equivalent).
This change was done in production at some point, but I don't have
serial number info. It should be easy enough to check the voltage
of the zener diode and the size (case) of the regulator.
Unfortunately, there is a laser tilt adjustment that is mechanical
as well.
Regards,
Tim Schwartz
Bristol Electronics
Time wrote:
After a failed lens cleaning attempt our 522 stopped working. It
wouldn't recognise CDs or if it did would just display 99.99 as
track length and still not play.
So, after a trip to the repair shop and being told to throw it
because repair would cost more than a new one I decided to have a
go myself. I took it apart, noted the pickup assembly (Sanyo
SF-P101 5/8P) and ordered a new one from the UK (I'm in NZ). I
removed the old one and replaced it exactly with the brand new
unit; I removed the temporary solder bridge and turned it on.
Still wouldn't work.
not exactly the same thing, this time it would just try to spin
the CD a tiny bit clockwise, then spin it backwards about one rev
(I'm guessing this is how it would try to slow the CD, had it been
spinning correctly?) then 'Er" would display on the display. I've
tested all connections, and everything seems fine. I also tested
some of the components such as the main spinup motor, and during
this testing the CD spun up properly! I don't get what happened,
and I can't accurately reproduce it but the cd spun up, the
display flashed --.-- a few times and attempted to play track one,
but after all these good signs it still ended up with 'Er' in this
attempt it also showed 16 tracks (the max that can show on the
display at once) even though the CD in it only had 8.
Does anyone know why this new unit isn't working, or recognise
these signs? I head somewhere that it might need
calibrating/aligning, does what I described sound like this could
be the problem?
Sorry for the long post, but hopefully this way I wont have to post
additional info. |
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True american Zero
Guest
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| Posted:
Thu Feb 10, 2005 3:12 am Post subject:
Re: Are You Tim from Emu? |
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Hello,
I knew a great guy named Tim Schwartz from a company called E-Mu
Systems in Santa-Cruz (USA). He wazs the service manager.
It would heve been funny !
Cheers
Georges |
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Time
Guest
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| Posted:
Thu Feb 10, 2005 8:41 am Post subject:
Re: Nad 522 optical assembly problem |
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The symptoms weren’t exactly the same. As I said, the CD player originally
stopped working because I was too rough while cleaning the lens, and that
seems to be exactly how the old unit acts; it spins the CD up, takes quite
a while looking and eventually just shows 99-99 on the display, it can
detect the CD (it also knows when there is no disc inserted) but just not
properly, as if the lens is damaged or scratched.
With the replacement; it usually doesn’t even spin the CD up, it just
gives a pathetic little spin and then says ‘Er’ as I said.
I don’t like the idea that this new unit could have been DOA, i went to
quite a lot of effort (not to mention the $$) to get it, how could I rule
this in/out?
-I am quite sure the laser is getting power a red light shows up on my
digital camera display, so I think ill stay away from adjusting laser
power.
-I think the unit is mechanically sound, it moves through all the right
axes, although I'm not sure why it doesn’t spin-up CD's correctly.
-And the unit at least attempts to focus; the lens bobs up and down under
the CD.
Do these symptoms make any sense?
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Thomas Sedlemyer
Guest
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| Posted:
Fri Feb 11, 2005 2:37 am Post subject:
Re: Nad 522 optical assembly problem |
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Did you look for the presense of a small drop of solder on the laser board
across two small pads. This is done to short across the laser diode to
protect from static discharge damage. If present it is removed after
installation by touching it with a hot soldering iron(grounded tip
prefferably).
Tom
"Time" <quattroauto@hotmail.com> wrote in message
news:758ff800c85fde93b4c44dffb15e1b17@localhost.talkaboutelectronicequipment
..com...
| Quote: | The symptoms weren't exactly the same. As I said, the CD player originally
stopped working because I was too rough while cleaning the lens, and that
seems to be exactly how the old unit acts; it spins the CD up, takes quite
a while looking and eventually just shows 99-99 on the display, it can
detect the CD (it also knows when there is no disc inserted) but just not
properly, as if the lens is damaged or scratched.
With the replacement; it usually doesn't even spin the CD up, it just
gives a pathetic little spin and then says 'Er' as I said.
I don't like the idea that this new unit could have been DOA, i went to
quite a lot of effort (not to mention the $$) to get it, how could I rule
this in/out?
-I am quite sure the laser is getting power a red light shows up on my
digital camera display, so I think ill stay away from adjusting laser
power.
-I think the unit is mechanically sound, it moves through all the right
axes, although I'm not sure why it doesn't spin-up CD's correctly.
-And the unit at least attempts to focus; the lens bobs up and down under
the CD.
Do these symptoms make any sense?
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Time
Guest
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| Posted:
Sat Feb 12, 2005 7:01 pm Post subject:
Re: Nad 522 optical assembly problem |
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| Yes, I already removed that. |
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