Cold start problems with CD transport

HI ,
i have the same identical problem on my cd10 (cdm4 d36), for a couple of minutes at the start (in winter... not in the summer) in the cdm doesn't recognize the toc, i try for many times until finally the toc is read... after this the cdm seems not have any other problems (it doesn't skip or have a bad sound).
I'm having this problem from many years ago, after the laser had been changed because dead in warranty, at the return from the service the cdm was working in this condition (****in' laser or bad setting ?? ), and is working in this condidion also today.
I tried to trim the two voltages of the laser as written in the service manual with few good results (a very little improvement).
i've red in the past that is a common problem of the cdm4, but i've never known if this is a problem of a bad laser or a problem of bad engineering.
I've seen also that in a data base for repairman (which i don't remember the name) this problem is reported and probably there is an hardware patch, unfortunately i'm not registered to this site
what kind of transport do you have?

DoctorWho70

this is the url:
http://www.euras.com/repair_tips_1/Philips/CDM4/CDM4_Philips.htm

has anyone the access to this database??

the interesting thing should be know some more informations about this pull-up resistor focus and this phantomatic CDM4 PHILIPS tech tip....
this ia a very common problem for cdm4 units, another guy on this forum sent me in the past the service manual to me because he also had the same problem and he couldn't solve it... it's very strange...
On some other post here i've red that the tda7310 is very sensitive to temperature....
I've also read of many problems on the most recent cdm units by philips of 10pf capacitor missed in the mount of the laser card, this units can't read the toc of the cd-r and also some original cd...

DoctorWho70

DoctorWho70 said:

the interesting thing should be know some more informations about this pull-up resistor focus and this phantomatic CDM4 PHILIPS tech tip....
this ia a very common problem for cdm4 units, another guy on this forum sent me in the past the service manual to me because he also had the same problem and he couldn't solve it... it's very strange...
On some other post here i've red that the tda7310 is very sensitive to temperature....
I've also read of many problems on the most recent cdm units by philips of 10pf capacitor missed in the mount of the laser card, this units can't read the toc of the cd-r and also some original cd...

DoctorWho70

Click to expand...

Hi,

Sounds like Newton has worn out the vertical suspension of the focus lens, and the focus servo gets out of (voltage) range. Can you measure the output voltage of the focus servo when the drive tends to startup ?

best

Had a similar problem with startup and turned out to be lubricant on the slide being sticky. I gave it a kick start to move the laser sled assembly and away it went. Cleaned and relubricated and no problem since.

tanks to all for the responses...

(Guido) i have trimmed the output of the focus servo for the 400mV as described in the service manual with very poor results... this night i will dismount the cd to check the system another time, last time my test measurements have been done with a commercial cd... not properly the philips test cd...
I've seen that it's very difficult to trim in the exact voltage because changing the cd, this voltage can change in +/-100mV, if my mind doesn't go wrong... i've made a media of various cd
i'll try to do a measurement after the cold start... and if there is a drift in this voltage.
(OT.. thanks for your clock, with a separate power supply it works very well since last year)

(Rabbitz) I thinked of a mechanical problem too... but i need to be sure of what doing, before destroying my jewel
The difference between cold and hot it can be for the hardness of the grease for the difference of temperature...
but did you have lubricate the orizontal swing arm or the focus vertical lens movement?
i could tell you a stupid thing, but i've never seen internally the feature of this laser lens movement, in some other laser i've seen that there is some magnets and coils but no guides...

Thanks in advance...
DoctorWho70

Sheldon

I don't think it's temperature related the problem I was having. The lubricant was acting like a glue settling between the bush and slide rod so when the player had to kick off, it had to break that bond. This only happened on start up after the player had been idle for a day or so. I tried Dextron automatic fluid which worked well for quite a while. I had recently bought another player on eBay which would play 12 tracks or so and go funny and skip like crazy. Tried the Dextron with no luck and would work intermittently. I tried to get some Molykote EM-30L which is perfect for the job but have to buy it in 1Kg lots at a zillion dollars. Ended up using Tamiya switch lubricant for their RC cars etc. Works like a charm and applied to both players... no probs since.

DoctorWho70
Sorry... I might have confused you with the laser sled. The player I have has the complete laser assembly running on a slide one side and a rod, the other.... think of a train on a track sort of thing. Looks like the one you have has the swivel arm which pivots on a ball. Don't play around with anything around the laser lens as it would then be kapoot.

DoctorWho70 said:

tanks to all for the responses...

(Guido) i have trimmed the output of the focus servo for the 400mV as described in the service manual with very poor results... this night i will dismount the cd to check the system another time, last time my test measurements have been done with a commercial cd... not properly the philips test cd...
I've seen that it's very difficult to trim in the exact voltage because changing the cd, this voltage can change in +/-100mV, if my mind doesn't go wrong... i've made a media of various cd
i'll try to do a measurement after the cold start... and if there is a drift in this voltage.
(OT.. thanks for your clock, with a separate power supply it works very well since last year)

(Rabbitz) I thinked of a mechanical problem too... but i need to be sure of what doing, before destroying my jewel
The difference between cold and hot it can be for the hardness of the grease for the difference of temperature...
but did you have lubricate the orizontal swing arm or the focus vertical lens movement?
i could tell you a stupid thing, but i've never seen internally the feature of this laser lens movement, in some other laser i've seen that there is some magnets and coils but no guides...

Thanks in advance...
DoctorWho70

Click to expand...

Hi

Could you check the amplitude of the RF level ? If this low it indicates worn out laser or dust in the optical lightpath

Sams' CD repair Faq is also usefull

best

thanks to all...
so, nothing to lubricate in the cdm4 and his laser arm and pivot?

this

Could you check the amplitude of the RF level ? If this low it indicates worn out laser or dust in the optical lightpath

Click to expand...

i'll do in the week-end if i have some time to spend about this problem...
but if it can be the laser ended, wouldn't it working bad also in the summer? it's about ten years that this laser work in this mode... it's spending too much time to die for my opinion and the last summer with 34° it worked without problems... also in the last ten summers...
And, the other thing you have to considerate is the total absence of skipping and other bad working after that the toc has been read (after a media of 1/2 minutes of play (error) play (error) play (error) play..... .
i'll do the measure only for desperation but for me the base problem isn't the laser life (it can be that now it's near his death, but not ten years ago... after the servicing where the told me they have replaced the laser and after some monts (when out of warranty for the murphy's law) it has started to do the problem... i know that "tell" doesn't mean that they really changed the laser.... but i want to believe it...)
Another interesting thing to tell is that some month ago,before trimming the laser and clean the lens, i changed all the el caps in the rf/servo board (saa8808/8809) with nichicon PF el.caps, but i didn't do nothing around the saa7310 in the microp. board.
what can i do to try eliminate this problem??
can i work around the power supply of the saa7310? i've read something of try to separate and decouple the power supply of this component... (the digital +5v is now done by a homemade low noise new circuit, not more a 7805, but without good results for this problems, but it's still in common with other components).
Any other idea???
It can be a problem of the cd10 circuit? anyone with machines of other brand, equipped with cdm4-xx have done the same or similar problem, it's a problem only of the marantz cd10?

Thanks in advance for the help
DoctorWho70

DoctorWho70 said:

i have the same identical problem on my cd10 (cdm4 d36), for a couple of minutes at the start (in winter... not in the summer) in the cdm doesn't recognize the toc,

Click to expand...

Do you mean this happens after switching on the player, or after starting the disc ?

When it plays, is it insensitive for external shocks, i.e. it doesn't skip when hit ?

best

i can see the problem at a cold start, (the first switch-on of the day or after some hours) then after two minutes of errors to read toc the problem disappear, you can see for one or two times more if you change the disc after two song... after this you can't see the problem until you keep switched off the player for many hours... after ten minutes you can replace many cds that the cd10 won't do any error, on the contrary, if you place the cd10 in stop (switched on), after ten minutes you can see one or two error when you press play...
for the external shocks, the player is 16 kg and has upside a nad306, but moving it and hitting it i don't see any errors or skipping ( normal hitting... some cm of movement laterally ).



Thanks
DoctorWho70

DoctorWho70 said:

i can see the problem at a cold start, (the first switch-on of the day or after some hours) then after two minutes of errors to read toc the problem disappear, you can see for one or two times more if you change the disc after two song... after this you can't see the problem until you keep switched off the player for many hours... after ten minutes you can replace many cds that the cd10 won't do any error, on the contrary, if you place the cd10 in stop (switched on), after ten minutes you can see one or two error when you press play...
for the external shocks, the player is 16 kg and has upside a nad306, but moving it and hitting it i don't see any errors or skipping ( normal hitting... some cm of movement laterally ).



Thanks
DoctorWho70

Click to expand...

Hi

This doesn't look like a laser, tracking or whatever problem, but plain electronics. Won't make it easier to solve

DoctorWho70 said:

Another interesting thing to tell is that some month ago,before trimming the laser and clean the lens, i changed all the el caps in the rf/servo board (saa8808/8809) with nichicon PF el.caps, but i didn't do nothing around the saa7310 in the microp. board.
what can i do to try eliminate this problem??
can i work around the power supply of the saa7310? i've read something of try to separate and decouple the power supply of this component... (the digital +5v is now done by a homemade low noise new circuit, not more a 7805, but without good results for this problems, but it's still in common with other components).

Click to expand...

I think you are looking at the wrong places.
Old CDM mechanisms (CDM2,4, etc.) take a lot of current to start. Reading the TOC or, after, hitting play for the first track.
The problem is that they (Philips/Marantz, etc) always used VERY weak trafos on the players, and the transport mech. is served with +/- 12V unregulated PSU (and regulated 5V).
Even worse, these PSUs are usually amazingly low capacitance, 470uF or 1,000uF caps is common.
Make a test: measure the 12V unregulated voltages as you hit play. You'll be scared, they sag 2~3V. Depending on the mains voltage that day (it varies) the player may not start at all.
Your post does give a clue: in the winter mains voltage is usually lower, because there's much more electricity consumption at homes.
I was given a Grundig CD301 (CDM4) for spare parts because over the years it went to the Grundig service some 5 times, even the laser was changed.
I've solved the problem with some big caps on the unreg. PSUs, and also 3,300uF caps on the connector for the flat cable to the transport. Because the transport on this player is mounted on the tray, it comes all the way out, and it's not very easy to fit some big caps there.
It starts and tracks much FASTER, no errors anymore.
Now imagine if I did on this player what I did to my CD650 some years ago: dedicated trafo and regulated +/-12V PSUs for the transport.

I dont think the powersupply on a cd10 is on the small side
But i think you should check the powersupply anyway. Sounds to me that one of the reg's does not make good contact untill it warms up a bit (by the others on the same coolingfin).

I've seen a lot of problems with the soldering of anything that gets heated up. Not shure if the cd10 is made in hasselt/belgium, but the older types (cd60/cd80) have this problem.

Fixed a cd60 this way by just resoldering the regs (without any measurements, just look and you can see the bad solderings). It was sent to repair 3 times, but nobody saw that

First fix it, then start thinking of modding. A stock cd10 should work without problems. I don't think you can mod the machine to improve realibility.

guido said:

Fixed a cd60 this way by just resoldering the regs (without any measurements, just look and you can see the bad solderings). It was sent to repair 3 times, but nobody saw that

Click to expand...

Yes, Guido, 'cold' solder joints on Philips gear is the most common thing to find, and this is not only valid for CDs.
That is such an automatic thing that I do that I forget to advice that.
I did resolder ALL this player, as I always do, and it didn't solve my problem.
I also used Philips red label contact spray on all the connectors, as I always do.
This are the first things to do, I agree.
I don't know the CD10's PSU, it surely is a higher-end player, but if this doesn't solve the problem, some PSU voltage measurements on the transport do no harm.

Thanks to Guido and Carlosfm for the help....
but i have to explicate something because i have modded the machine last year (without reaching any improvement for the problem).
the regulators 7805 7809 and 7909 had been replaced last year by a new power supply circuit low noise similar to jung-didden referenced by an ad580jh... these are the three voltages which are supplying the cdm4... now they are very stable and this evening i made some test and at the first start i've checked they with my old scope and i have seen that there aren't any drop out during the error in reading the toc.
so i exclude that there isn't a problem of dimension of the secondary of the trafo or to increment the capacity of the power supply filter , i have also replaced all the rectifiers with shottky diodes recovering 0.5/1 Volts on all the unregulated voltages before the regulators...

The solders... i had redo many of theese in the power supply, dac, and hf/servo boards last year, i've checked visually the laser board , i have disconnected and reconnected all the cables and connector internally, of the laser and of any other board present in the cd... but i exclude the cold solder because the cold solder cause ever problem when you move the board where it's present, in my case you can hit the cd whit violence without any problem (it's impossible to have a skip - 16kg) and i have also pressed all the boards in every point internally during the cd working but no problems reached...
I've measured the voltage of the laser, 50mV perfect, and the focus voltage (the media) the sine wave 150/200mVpp, 300mv with a cd-r and 450/500mV with a original cd

BUT... i've made some test with a transparent plastic cd to viev the movement of the laser head and the arm...
The interesting thing that i've seen this evening during the initial errors is that the laser try to focus and make a great excursion of the lens, but i noted total absence of tremor of the arm ( to reach the first track ?? )...
after 5/6 test (pressing play) and about after a minute this movement appeared and after i have placed a good cd and the toc was reached...

So... could it be this initial absence of this radial tremors of the swing arm of the laser head, useful to reach the track, the problem of my cd???
anyone knows more of this movement, what is controlling this movement?

Thanks in advance
have a good week-end

DoctorWho70