#1495214 - 20/09/08 09:36 AM
Alpine cda-7949 acting weird
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csk
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Registered: 18/06/08
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Okay, I bought a used alpine cda-7949. It powers up perfectly and all of the functions work, but I'm having problem playing cd's. Here's the weird thing: When I put a cd in, it spins very slowly and makes a loud noise like it's rubbing against something inside of the unit. But, when I tilt the unit almost vertically(face of the unit towards the sky), the noise goes away and the cd spine and plays perfectly. What would cause the cd player to do this? Any suggestions as to what I can do to fix it? Please help because I want to get this awesome deck working.
Thanks
Chris
_________________________
head unit- Alpine CDA-7949
front speakers- Polk MMC6500 components
rear fill- Polk MMC570
Subs- 2 10" Alpine SWR-1041d
Amps- Eclipse XA4000, Hifonics BXI2006D
Monster Cable and Stinger cables and accessories
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#1495219 - 20/09/08 09:46 AM
Re: Alpine cda-7949 acting weird
[Re: csk]
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keep_hope_alive
Snooch to the Nooch
SD I chew on Mike Tyson's ear
Registered: 24/04/07
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Loc: Quad Cities, IL
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there is a spring that holds the front of the cd tray in place. that spring is missing and the disc is rubbing against the frame. i've fixed that on similar model units before. i have no idea how the spring disappears.
open the unit up, look for the spring hooks at the front of the cd mechanism (right where the cd loads), get a spring that seems the right length and hook it on. you'll need some pretty fine needle nose pliers to hook the spring on. just look around and you'll find it.
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#1495230 - 20/09/08 10:26 AM
Re: Alpine cda-7949 acting weird
[Re: keep_hope_alive]
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csk
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Registered: 18/06/08
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I just checked the springs, and it seems that everything is in place. The spring that you mentioned I believe is under the cd tray and attaches to a metal piece closer to the loading mechanism, right? If so, it's attached. Any other suggestions that I might look into. Thanks for you response.
Alpine CDA-7949
2 Alpine SWR-1041D
Polk MMC6500 components
Polk MMC570 rear fill
Eclipse XA400
Hifonics BXI2006D
_________________________
head unit- Alpine CDA-7949
front speakers- Polk MMC6500 components
rear fill- Polk MMC570
Subs- 2 10" Alpine SWR-1041d
Amps- Eclipse XA4000, Hifonics BXI2006D
Monster Cable and Stinger cables and accessories
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#1495258 - 20/09/08 12:27 PM
Re: Alpine cda-7949 acting weird
[Re: csk]
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keep_hope_alive
Snooch to the Nooch
SD I chew on Mike Tyson's ear
Registered: 24/04/07
Posts: 8659
Loc: Quad Cities, IL
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play the cd with the cover off and look for the place it's rubbing. that tray is not level, something is missing or broke. it should be a simple fix.
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#1496627 - 22/09/08 09:35 PM
Re: Alpine cda-7949 acting weird
[Re: keep_hope_alive]
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csk
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Registered: 18/06/08
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I haven't had a chance to take the cover of to see where the cd is rubbing, but I did find something that might be causing the problem. I'm no cd technician by any means and don't know the names of the pieces, but I will give it a shot. I opened up a functional cda-7940 and compared the cd player to the 7949 cd player. Very similar, and after inspecting the 7940's components and springs, I believe the the 7949 player is intact. But, I did notice one thing about the 7940 that was different than the 7949. Again, I don't know the terminology, so here we go. When the cd is fed into the player, I believe it sits on the spindle. There is a black circular piece located above the spindle, which sits under and touches a plastic black piece that is attached the the cd mechanism cover. Under the plastic black piece, I found a small sticky square. When I turn the circular piece above the spindle in the 7940 by hand, it resists because of the sticky square. But, in the 7949, it seems that the square has rubbed off and it turns freely when I spin it by hand. Could this cause my 7949 to make that loud clicking noise when the cd spins on a flat surface. Again, the cd plays normally when the unit face towards the sky. Sorry for the long post, but I'm just trying to troubleshoot. Thanks.
_________________________
head unit- Alpine CDA-7949
front speakers- Polk MMC6500 components
rear fill- Polk MMC570
Subs- 2 10" Alpine SWR-1041d
Amps- Eclipse XA4000, Hifonics BXI2006D
Monster Cable and Stinger cables and accessories
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#1496818 - 23/09/08 08:38 AM
Re: Alpine cda-7949 acting weird
[Re: csk]
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keep_hope_alive
Snooch to the Nooch
SD I chew on Mike Tyson's ear
Registered: 24/04/07
Posts: 8659
Loc: Quad Cities, IL
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ah. i've had both of those units within the last couple years, and taken both apart for various reasons.
it sounds like your issue is that the disc isn't getting up to speed, the clicking (i'm assuming) is due to some physical friction. really, the only way to see what's going on is to remove the cover and power up.
i'm not sure what the "small sticky square" is doing. I have two CDA-7930's, one of which is just sitting on a shelf. I can pop the cover and let you know if that has it. I also have several Alpine service manuals from that era so I can see if it has a part number or description. I don't have a 7949 service manual. if i were you, i'd try to find a service manual so you can do a parts inventory to ensure nothing is missing.
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#1498422 - 25/09/08 09:37 AM
Re: Alpine cda-7949 acting weird
[Re: keep_hope_alive]
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csk
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Registered: 18/06/08
Posts: 13
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If you can try and find the part number or description of the "small sticky square", let me know. I am in the process of getting a 12 volt power supply to power up my 7949 so that I can work with it in the house...compared to in my car where I have to power it up everytime. Also have another question. I bought a cda-7842 on ebay and the rca cords have a short in them. I tried to find replacement alpine rca's on the web, but couldn't. Are they available and do you know where I might find some. If not, is there a way to fix these without damaging the unit. I did notice the rca wires are connected to the circuit board below the cd player. I don't want to mess the functioning cd player up in the process. Thanks.
_________________________
head unit- Alpine CDA-7949
front speakers- Polk MMC6500 components
rear fill- Polk MMC570
Subs- 2 10" Alpine SWR-1041d
Amps- Eclipse XA4000, Hifonics BXI2006D
Monster Cable and Stinger cables and accessories
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#1498737 - 25/09/08 03:30 PM
Re: Alpine cda-7949 acting weird
[Re: csk]
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keep_hope_alive
Snooch to the Nooch
SD I chew on Mike Tyson's ear
Registered: 24/04/07
Posts: 8659
Loc: Quad Cities, IL
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just desolder them from the board and replace them with new female RCA's. You can either buy some or make some. You won't hurt the unit by desoldering the existing cables, just take a good note of where they were (channel and ground).
I keep a spool of RCA wire and a bunch of ends to make my own cables, pretty easy. You just need a good soldering iron and some helping hands - Parts Express or MCM Electronics sells all that pretty reasonably.
You definately need a power supply to bench test, I figured you were doing that already. That is the only way to diagnose and repair electronics. You'll find it's very useful.
Let me know if you need help finding product or other parts. Check Pacparts.com for alpine parts.
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#1501115 - 29/09/08 10:47 PM
Re: Alpine cda-7949 acting weird
[Re: keep_hope_alive]
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csk
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Registered: 18/06/08
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Still awaiting my power supply so I can work on the cda-7949. I've got another question. The cda-7842 with the shorted rca's also has another problem....the display doesn't light up. All of the buttons and other functions light up though. I've cleaned the contacts but still can't get it to light up. When I plug the 7842's face into the 7940, the display lights up, thus it's not a display bulb problem. Any suggstions on what I should try to get the display to light up in the 7842 unit? Is there something faulty on the circuit board that could cause this? Thanks.
_________________________
head unit- Alpine CDA-7949
front speakers- Polk MMC6500 components
rear fill- Polk MMC570
Subs- 2 10" Alpine SWR-1041d
Amps- Eclipse XA4000, Hifonics BXI2006D
Monster Cable and Stinger cables and accessories
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#1501127 - 29/09/08 11:04 PM
Re: Alpine cda-7949 acting weird
[Re: csk]
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keep_hope_alive
Snooch to the Nooch
SD I chew on Mike Tyson's ear
Registered: 24/04/07
Posts: 8659
Loc: Quad Cities, IL
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don't swap faceplates - that's a good way to damage a head unit. they aren't universal.
the problem is in the head unit for your 7842. only with a service manual would you be able to fix it.
i had an Alpine hu that had the faceplate swapped once, damaged something inside the hu so I sent it to Alpine for service, came back fixed. no idea what they did - it was over 13 years ago.
that said, the controller for the display is in the faceplate. so it must be a supply voltage problem with the 7842.
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#1501937 - 30/09/08 09:41 PM
Re: Alpine cda-7949 acting weird
[Re: keep_hope_alive]
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csk
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Registered: 18/06/08
Posts: 13
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Thanks for the help. I have a few decks that need work, but once and if I get them fixed, I'll feel like I've accomplished something...kind of a hobby of mine. I have another deck, a cdm-7857 that will feed the cd, play it perfectly, but when I eject it, the motor continues run in like it's still ejecting the disc, and then the error message comes up on the display. I actually thought the eject button on the faceplate was sticking, so I investigated and got the button to work properly. I haven't tried tried the deck since fixing the button because I'm still awaiting my power supply. I'm hoping that's all it was. So, a grand total of four decks with various issues. I guess that's what you should expect with used players.
_________________________
head unit- Alpine CDA-7949
front speakers- Polk MMC6500 components
rear fill- Polk MMC570
Subs- 2 10" Alpine SWR-1041d
Amps- Eclipse XA4000, Hifonics BXI2006D
Monster Cable and Stinger cables and accessories
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#1501965 - 30/09/08 10:08 PM
Re: Alpine cda-7949 acting weird
[Re: csk]
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keep_hope_alive
Snooch to the Nooch
SD I chew on Mike Tyson's ear
Registered: 24/04/07
Posts: 8659
Loc: Quad Cities, IL
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i have two CDA-7930's, one of which I repaired a display on in a blog. both work perfect. a CDM-7874 that had a display resistor that had a poor solder connection - fixed and working well. a DVA-7996 that has no output but working optical out (soon project). A working CDA-9851, and a working CDA-7838.
i recently sold a CDA-7940, two CDA-7939, and a CDA-7949. the 7949 wouldn't read discs but the others were perfect.
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#1502602 - 01/10/08 06:04 PM
Re: Alpine cda-7949 acting weird
[Re: keep_hope_alive]
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csk
SD Newbie
Registered: 18/06/08
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Well, I got my power supply in today. My first objective is to fix my cda-7949. If you recall, when I put a cd in the player, the disc would spin slowly and make a noise like it was rubbing against something. But when I face the unit to the sky, the noise would go away and the player would read the cd. I opened the top of the unit and put a cd in...it is rubbing against something and it seems to be one of the white tabs that move when the disc is inserted. I took my thumbs and barely shifted the cd tray to the back, and kept it at that position. The noise ceased, the cd spun normaly, and the player read the cd. I've checked all of the springs and they are present(I compared them to the cda-7842 player I had because they have fairly similar cd players). When I load the cd, the tray seems to drop down in it's normal position, so I am not sure why I get the rubbing noise. Let me know what you think and thank you.
_________________________
head unit- Alpine CDA-7949
front speakers- Polk MMC6500 components
rear fill- Polk MMC570
Subs- 2 10" Alpine SWR-1041d
Amps- Eclipse XA4000, Hifonics BXI2006D
Monster Cable and Stinger cables and accessories
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#1503718 - 03/10/08 08:19 AM
Re: Alpine cda-7949 acting weird
[Re: csk]
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keep_hope_alive
Snooch to the Nooch
SD I chew on Mike Tyson's ear
Registered: 24/04/07
Posts: 8659
Loc: Quad Cities, IL
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if the tray is not in the right location then something is missing or broken (obviously).
without a service manual it will be difficult to diagnose the missing part. the 7842 is still different than the 7949 and a different year.
what part of the disc is rubbing? the side or the bottom?
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#1507389 - 08/10/08 07:35 PM
Re: Alpine cda-7949 acting weird
[Re: keep_hope_alive]
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csk
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Registered: 18/06/08
Posts: 13
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Yeah...one down. I finally fixed my cda-7949. Seeing that it was working perfectly except for the cd rubbing and making a horrible noise in the player, I decided to replace the spring that attached the cd tray in place...and wolla...it works now. I guess the old spring lost its tension and made the tray drop too low, thus I got the rubbing noise. Unfortunately, the spring was taken from a working cda-7842 player, but I'm sure these springs can be purchased somewhere. So, I went from a non-working cd player, to fixing the player, to the cd in the player making a rubbing noise, to a fixed player. It took time and patience, but it's worth it. And I've actually learned about the mechanics of the player now.
_________________________
head unit- Alpine CDA-7949
front speakers- Polk MMC6500 components
rear fill- Polk MMC570
Subs- 2 10" Alpine SWR-1041d
Amps- Eclipse XA4000, Hifonics BXI2006D
Monster Cable and Stinger cables and accessories
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#1507445 - 08/10/08 11:04 PM
Re: Alpine cda-7949 acting weird
[Re: csk]
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keep_hope_alive
Snooch to the Nooch
SD I chew on Mike Tyson's ear
Registered: 24/04/07
Posts: 8659
Loc: Quad Cities, IL
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so in the end, my original diagnosis was accurate. cool. i keep a lot of spare parts from electronics. i snagged a spring from an old tape deck and used it on mine - worked great. not sure where you'd buy one new.
i'm glad you got the joy of repairing the unit - it's a good feeling.
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