CD player skips - how to repair?
Discussion
Hi
I have a Harman-Kardon HD7500 which was quite an expensive and well thought of machine in its day.
Bought on ebay in perfect working order but (surprise, surprise) it sounds good but skips from time to time, particularly with CDs that have many tracks - and does it enough to make it unusable.
What kind of thing would have gone wrong and could it be repaired - I would feel bad throwing it out but on the other hand if it's effectively irreperable I might have to?
Thanks for any advice
tgr
I have a Harman-Kardon HD7500 which was quite an expensive and well thought of machine in its day.
Bought on ebay in perfect working order but (surprise, surprise) it sounds good but skips from time to time, particularly with CDs that have many tracks - and does it enough to make it unusable.
What kind of thing would have gone wrong and could it be repaired - I would feel bad throwing it out but on the other hand if it's effectively irreperable I might have to?
Thanks for any advice
tgr
tgr said:
Hi
I have a Harman-Kardon HD7500 which was quite an expensive and well thought of machine in its day.
Bought on ebay in perfect working order but (surprise, surprise) it sounds good but skips from time to time, particularly with CDs that have many tracks - and does it enough to make it unusable.
What kind of thing would have gone wrong and could it be repaired - I would feel bad throwing it out but on the other hand if it's effectively irreperable I might have to?
Thanks for any advice
tgr
Have you had it apart and cleaned the lens ? 3 minute job with a cotton bud. I have a Harman-Kardon HD7500 which was quite an expensive and well thought of machine in its day.
Bought on ebay in perfect working order but (surprise, surprise) it sounds good but skips from time to time, particularly with CDs that have many tracks - and does it enough to make it unusable.
What kind of thing would have gone wrong and could it be repaired - I would feel bad throwing it out but on the other hand if it's effectively irreperable I might have to?
Thanks for any advice
tgr
Pic of internal layout here http://www.usedottawa.com/ReportSelectUsedAdPhoto2...
Its likely that the silicon grease, that lubricates the worm and wheel laser mechanism, has dried out. Some of this http://uk.farnell.com/servisol/200002000/grease-si... or an equivalent should sort the mechanical side.
If there is no improvement after doing the above then the laser may be tired. You can fiddle around optimising the focus and eye pattern etc but tbh its probably best to let it go......
The laser in that player is very common and easily obtained and replaced.
If it's an early version it could be a KSS150A or KSS210A - if it's the mark 2 version it'll be the KSS210A.
These lasers are used in loads of different players (Cambridge / Arcam / Sony / etc..).
You can get them on Ebay usually for under £10.
Should take even an inexperienced person less than an hour to fit (but a soldering iron with a fine tip will be required).
It's all plug and play, but the soldering iron is required to removed a solder link on the laser (anti static prevention).
If it's an early version it could be a KSS150A or KSS210A - if it's the mark 2 version it'll be the KSS210A.
These lasers are used in loads of different players (Cambridge / Arcam / Sony / etc..).
You can get them on Ebay usually for under £10.
Should take even an inexperienced person less than an hour to fit (but a soldering iron with a fine tip will be required).
It's all plug and play, but the soldering iron is required to removed a solder link on the laser (anti static prevention).
Thanks both - it is the MkII version.
I did try to clean the lens but that didn't have any effect as far as I could tell. Could always try again as it costs nothing
I have tried to cycle through from first to last track, which seems to work, so I would have thought that movement of the laser assembly is not impeded?
It sounds good that the lasers are readily available and easy to fit - is there any way to separate the well-manufactured ones from the rubbish?
Apologies if these are simplistic questions
tgr
I did try to clean the lens but that didn't have any effect as far as I could tell. Could always try again as it costs nothing
I have tried to cycle through from first to last track, which seems to work, so I would have thought that movement of the laser assembly is not impeded?
It sounds good that the lasers are readily available and easy to fit - is there any way to separate the well-manufactured ones from the rubbish?
Apologies if these are simplistic questions
tgr
You not only want to clean the top of the laser, but under the cap as well.
See this link for an explanation.
Also - if the player previously belonged to a smoker, it's highly likely that nicotine has contaminated the laser.
EDIT: It's also a good idea to clean the sled rails and gears with alcohol or methylated spirits, and then lubricate with light machine oil (sewing machine oil) such as this - I know that silicon grease was recommended above, however for the 20 odd years or so that I serviced CD players I used oil, as grease has a tendency to go sticky.
See this link for an explanation.
Also - if the player previously belonged to a smoker, it's highly likely that nicotine has contaminated the laser.
EDIT: It's also a good idea to clean the sled rails and gears with alcohol or methylated spirits, and then lubricate with light machine oil (sewing machine oil) such as this - I know that silicon grease was recommended above, however for the 20 odd years or so that I serviced CD players I used oil, as grease has a tendency to go sticky.
Edited by TonyRPH on Friday 20th October 16:33
As Tony says, sewing machine oil is a good substitute for the original silicone grease. Back in the day I used to use the equivalent of this http://uk.farnell.com/ambersil/6130008500/grease-s... . The spray can should come with a flexible plastic tube to help direct the spray where you need it without having to disassemble.
The grease dries and hardens over time and then gets pushed to the ends of the worm and wheel mechanism. The player's error correction runs out of brain power at the outer edge of the disc ( last tracks on the album ).
The grease dries and hardens over time and then gets pushed to the ends of the worm and wheel mechanism. The player's error correction runs out of brain power at the outer edge of the disc ( last tracks on the album ).
I took the case off. It was evident from the screws that the case had been removed before.
I cleaned the lens carefully as advised, also underneath, having removed the cap. I used window cleaner for this and cleaned it fairly comprehensively.
I then cleaned the runner and the metal shaft with alhohol and applied light oil with a cotton wool bud.
Once reassembled, cds are barely read any better than before. Most of the time the player successfully reads how many tracks are on the disk (though not always). However it hunts noisily the exact location of tracks and, once it has decided, skips after a few seconds, sometimes within that track, sometimes to an entirely different track - in no discernable pattern. Sound - when it comes out - is very good, however.
What is unknown is what has been done to the machine before I got it. This is what worries me, as I am fairly certain I haven’t ballsed things up myself. If someone before me has mucked around with the calibration I don’t have the equipment to reset it and it’s probably beyond economic repair, unless you think otherwise?
Hmmm.
I cleaned the lens carefully as advised, also underneath, having removed the cap. I used window cleaner for this and cleaned it fairly comprehensively.
I then cleaned the runner and the metal shaft with alhohol and applied light oil with a cotton wool bud.
Once reassembled, cds are barely read any better than before. Most of the time the player successfully reads how many tracks are on the disk (though not always). However it hunts noisily the exact location of tracks and, once it has decided, skips after a few seconds, sometimes within that track, sometimes to an entirely different track - in no discernable pattern. Sound - when it comes out - is very good, however.
What is unknown is what has been done to the machine before I got it. This is what worries me, as I am fairly certain I haven’t ballsed things up myself. If someone before me has mucked around with the calibration I don’t have the equipment to reset it and it’s probably beyond economic repair, unless you think otherwise?
Hmmm.
Your description of the fault is that of a failed laser - assuming nobody has fiddled with adjustments.
However - usually if adjustments have been fiddled with, there will likely be issues with reading the TOC (at initial insertion of a CD), and track selection is often slow, to the point of giving up when a track cannot be locate - but - having said that - a failed laser can give similar symptoms, depending on how far gone it is.
Are you using original CDs or copies?
I would buy a cheap laser off Ebay and swap it out - you have nothing to lose but the cost of the laser.
Another thing to consider, is the flexible cable that goes from the laser to the main board. Does your machine have a flat cable or is it 'normal' thin wires?
This is the link you will need to desolder once the new laser is installed. (bottom right)
However - usually if adjustments have been fiddled with, there will likely be issues with reading the TOC (at initial insertion of a CD), and track selection is often slow, to the point of giving up when a track cannot be locate - but - having said that - a failed laser can give similar symptoms, depending on how far gone it is.
Are you using original CDs or copies?
I would buy a cheap laser off Ebay and swap it out - you have nothing to lose but the cost of the laser.
Another thing to consider, is the flexible cable that goes from the laser to the main board. Does your machine have a flat cable or is it 'normal' thin wires?
This is the link you will need to desolder once the new laser is installed. (bottom right)
Edited by TonyRPH on Saturday 28th October 15:21
Thanks Tony
I'm using original cds in good condition - so I'm assuming that the problem shouldn't be anything to do with those.
The wires going from the laser assembly to the PCB are bunched thin wires, and I did notice that one of them - the uppermost one connected to the left hand side (red) connector of the laser assembly - was frayed. More evidence I suppose that the machine has been interfered with.
tgr
I'm using original cds in good condition - so I'm assuming that the problem shouldn't be anything to do with those.
The wires going from the laser assembly to the PCB are bunched thin wires, and I did notice that one of them - the uppermost one connected to the left hand side (red) connector of the laser assembly - was frayed. More evidence I suppose that the machine has been interfered with.
tgr
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