I bought some weeks ago a cd303 player, partially recaped, and in a general decent order (I think the dude said something about the drawer leds-i don't know). As I am one of those guys that blanket recap all things I dismantle the thing to make a list.
The surprise come a little later when after assembly started to sound very "synth-like" and craped out-there is a possibility that I inverted the "data" and "psu" lines from the servo bord, I did color marked the sockets... - can't really confirm it- but hey, not the first time that I did something stupid.
I did put some Caps back on the bord telling my self crazy reasons for it 🙂) but no the CPU from the servo was dead.
The worst of the worst a old rare cpu- and factory programed - at first I found in soume posts and video clips a dude that had a "soundtraces" blue bord with a atmel chip on-no luck there, never find who actually sells them. But again I stroke some luck and find a set of servo + decoding boards the seller accepted my offer and I was back I business.
Just replace The MAB 8440DP D011 and he plays once again.
(I know most people don't like full recaps but I do, on my original boards or the replacement ones there where not of the philips axial blue electrolyticss in good shape except the 1uF ones all half the value and with a esr of many many many ohms)
I have to say I bought it to recover some parts from it, as a while back I seen some dac boards that required this dac (tda1540)...
But now. OMG that mech 🙂) .... How can I not like it? and anyway not I have another two DACs and filter that at this moment have no reason to believe that they don't work.
Now:
Need to dismantle it again and clean it as it still dirty and I hate having to pealing dead foam with my finger tips.
Adjust the drawer as it is not quite centered
Find and Replace ALL el-caps from drwaer board and laser board + fine tune the laser (don't know how-I have the tools done it before but with a much better service manual... one that I could read🙂) )
Find a solution for the annoying the in the clip :
I don't like the look of the orange or axial film caps eighter- I will pull some for proper testing
Decide what decoding board is "better" type C or type A and If they are replaceable without having to retune things...
I had something else to say-I forgot.
Any thoughts you have to share will be gratefully received.
The surprise come a little later when after assembly started to sound very "synth-like" and craped out-there is a possibility that I inverted the "data" and "psu" lines from the servo bord, I did color marked the sockets... - can't really confirm it- but hey, not the first time that I did something stupid.
I did put some Caps back on the bord telling my self crazy reasons for it 🙂) but no the CPU from the servo was dead.
The worst of the worst a old rare cpu- and factory programed - at first I found in soume posts and video clips a dude that had a "soundtraces" blue bord with a atmel chip on-no luck there, never find who actually sells them. But again I stroke some luck and find a set of servo + decoding boards the seller accepted my offer and I was back I business.
Just replace The MAB 8440DP D011 and he plays once again.
(I know most people don't like full recaps but I do, on my original boards or the replacement ones there where not of the philips axial blue electrolyticss in good shape except the 1uF ones all half the value and with a esr of many many many ohms)
I have to say I bought it to recover some parts from it, as a while back I seen some dac boards that required this dac (tda1540)...
But now. OMG that mech 🙂) .... How can I not like it? and anyway not I have another two DACs and filter that at this moment have no reason to believe that they don't work.
Now:
Need to dismantle it again and clean it as it still dirty and I hate having to pealing dead foam with my finger tips.
Adjust the drawer as it is not quite centered
Find and Replace ALL el-caps from drwaer board and laser board + fine tune the laser (don't know how-I have the tools done it before but with a much better service manual... one that I could read🙂) )
Find a solution for the annoying the in the clip :
Decide what decoding board is "better" type C or type A and If they are replaceable without having to retune things...
I had something else to say-I forgot.
Any thoughts you have to share will be gratefully received.
Attachments
Done a little more work on them.
I measured some cap samples and all had old age problems 😀 So I will change most of them, philips "orange drops" are on the list too but I don't have the right raster for them. I thought I have but they are exactly reversed (15mm for 01u instead of 10 and viceversa)
Sadly I managed to F-up another RLC meter (it my third one) and for now I have just some crappy ones.
new caps from tme are ordered but it will take a while....
Before this I did put a scope on it and the YEDS disc, one channel had a little delay on it (I forgot to screen shot the scope) less then half of the what ever wave it was on....
In the service manuals can find some things a symmetry pot . just outside one of the dacs and on the actual PCB,(this is changed with just a resistor, and marked in a foot note in the SM my bet is that this is the Perpetrator) on the servo pcb a pot footprint around the TCA something ic that looks like a differential amp for error correction... maybe to play with that for the oscillation.
I measured some cap samples and all had old age problems 😀 So I will change most of them, philips "orange drops" are on the list too but I don't have the right raster for them. I thought I have but they are exactly reversed (15mm for 01u instead of 10 and viceversa)
Sadly I managed to F-up another RLC meter (it my third one) and for now I have just some crappy ones.
new caps from tme are ordered but it will take a while....
Before this I did put a scope on it and the YEDS disc, one channel had a little delay on it (I forgot to screen shot the scope) less then half of the what ever wave it was on....
In the service manuals can find some things a symmetry pot . just outside one of the dacs and on the actual PCB,(this is changed with just a resistor, and marked in a foot note in the SM my bet is that this is the Perpetrator) on the servo pcb a pot footprint around the TCA something ic that looks like a differential amp for error correction... maybe to play with that for the oscillation.
Attachments
Don't mess with the servo board capacitor values.
Always work with antistatic wrist band to earth 1 - 10 Mohm. One spark can kill the chips.
Replacements: MLCC's good for smaller values in digital path, particularly C0G type and less so X7R.
Low esr Polymers caps for larger values, particularly on chip power consumers and regulators.
'ringing' within digital circuits is usually mitigated by increasing the R in the capacitors, Tantalums in that case. Assuming they are the silver axial ones in your image, or perhaps polyester, either way don't replace them, they're good and reliable.
Don't try to adjust the laser, focus, tracking etc unless you know exactly what your doing, unless pandora is you friend and you have time...a scope, the exact sync frequencies, the ability to adjust in real time ( many older Phillips mechs don't have that ability).
Always work with antistatic wrist band to earth 1 - 10 Mohm. One spark can kill the chips.
Replacements: MLCC's good for smaller values in digital path, particularly C0G type and less so X7R.
Low esr Polymers caps for larger values, particularly on chip power consumers and regulators.
'ringing' within digital circuits is usually mitigated by increasing the R in the capacitors, Tantalums in that case. Assuming they are the silver axial ones in your image, or perhaps polyester, either way don't replace them, they're good and reliable.
Don't try to adjust the laser, focus, tracking etc unless you know exactly what your doing, unless pandora is you friend and you have time...a scope, the exact sync frequencies, the ability to adjust in real time ( many older Phillips mechs don't have that ability).
Did you find someone who has the range of these Philips controllers? Last time i looked it was https://www.bramjacobse.nl
I did not mess with the values, and I do indeed test parts before replacement.
The silver axial caps are micropoco a polyprop. of high tolerance 1-5%.....
I choose to replace some of the caps because they did test somewhat high in leakeage, and the popular knowledge as higher spec. build use film cap for dacs.
Not in the hope to actual repair that peculiar oscillation more for a general improvement and service of the machine, I did also do some mostly useless things like lower the transistors and caps, rework some solder joints, straiten the dac bord 🙂)
I found that site...
I also found a guy (on fb) with some spdif adapter that I'm thinking into buying...
The silver axial caps are micropoco a polyprop. of high tolerance 1-5%.....
I choose to replace some of the caps because they did test somewhat high in leakeage, and the popular knowledge as higher spec. build use film cap for dacs.
Not in the hope to actual repair that peculiar oscillation more for a general improvement and service of the machine, I did also do some mostly useless things like lower the transistors and caps, rework some solder joints, straiten the dac bord 🙂)
I found that site...
I also found a guy (on fb) with some spdif adapter that I'm thinking into buying...
Polyprops fine, they rarely degrade.
Remember you're in the digital domain here. It's all high frequencies and square waves.
It's all about reducing the noise before the power/ signal gets to where it's going.
You're using capacitors that are good in an analogue environment.
For example: Any digital IC where there are 100nF ceramic noise suppressors , try C0G/ NP0 MLCCs (Multi Layered Ceramic Capacitors) in place of.
The stability of Polymer capacitors on the outputs of regulators are effective, these values are typically around 10µf, 47µf and 100µf, bypass caps.
Oscillation, within the digital circuit, on the servo board?
In some of those old small value lytic capacitors you removed, these may require to be replaced with tantalum caps as they have 1-5Ω resistive component as well as good stability, which helps to stop 'ringing' within the digital circuits. The error correction functions of the servo control have data loops of a high rate. Reducing the 'work' they do makes it easier for the machine to process the laser data more efficiently and a cleaner signal results. Not having that resistive component can increasing looping to the extent of oscillation that will translate to the DAC.
Sometimes anti-aliasing sonics.
Remember you're in the digital domain here. It's all high frequencies and square waves.
It's all about reducing the noise before the power/ signal gets to where it's going.
You're using capacitors that are good in an analogue environment.
For example: Any digital IC where there are 100nF ceramic noise suppressors , try C0G/ NP0 MLCCs (Multi Layered Ceramic Capacitors) in place of.
The stability of Polymer capacitors on the outputs of regulators are effective, these values are typically around 10µf, 47µf and 100µf, bypass caps.
Oscillation, within the digital circuit, on the servo board?
In some of those old small value lytic capacitors you removed, these may require to be replaced with tantalum caps as they have 1-5Ω resistive component as well as good stability, which helps to stop 'ringing' within the digital circuits. The error correction functions of the servo control have data loops of a high rate. Reducing the 'work' they do makes it easier for the machine to process the laser data more efficiently and a cleaner signal results. Not having that resistive component can increasing looping to the extent of oscillation that will translate to the DAC.
Sometimes anti-aliasing sonics.
That might be the White 22nF film caps, but i dont know the circuit. Key area is around the SAA an TDA chips.
Assuming you have everything 100% functional from the laser to the PCB...
Have you checked the PPL clock circuits, the crystal can drift, usually there are one or to precision resistors, a couple of MLCC C0G's matched to the loading of the new crystal will fix that, 5ppm stability crystals in that HC49 package now not so easy to find, post here if you do find a cheap source.