Don't worry too much about the Kill line yet.
Look at your readings for the Regulators............6593......a Negative 15 Volt Regulator with only 11 Volts (I am assuming you mean Minus 11 Volts?). This should ring some alarm bells.
Next look at what that Minus 15 Volt feeds.
1) The DAC (TDA1541...nice 🙂 ) This Negative 15 Volts to the TDA1541 is a VERY important supply.
2) The Output OpAmps. These will not function so well with an inconsistent supply (+15V and -11V)
You need to find whether the Regulator is faulty and not giving out the correct -15 Volts or, the -15 Volts is being dragged down because of a fault somewhere....DAC (unlikely, these are very robust IC's, though not impossible) or an OpAmp.
I can't find (quickly and I've got to go to work now) where the +/- 10 Supplies are derived from on the Servo section. If these are derived from the +/- 15Volts then there may be a problem here however, you say the CD spins OK so very doubtfull.
Seeing as it plays but no sound I'd start with the Audio section.
Can you pull the Regulator and supply the -15 V from a Bench PSU? Carefull to monitor the current here though or you could do more damage than you cure !
If easier, remove everything, one by one, that is supplied by the +/- 15 V untill the -15 V comes back up and you should have your problem......hopefully !
I'd start with the OpAmps.
Look at your readings for the Regulators............6593......a Negative 15 Volt Regulator with only 11 Volts (I am assuming you mean Minus 11 Volts?). This should ring some alarm bells.
Next look at what that Minus 15 Volt feeds.
1) The DAC (TDA1541...nice 🙂 ) This Negative 15 Volts to the TDA1541 is a VERY important supply.
2) The Output OpAmps. These will not function so well with an inconsistent supply (+15V and -11V)
You need to find whether the Regulator is faulty and not giving out the correct -15 Volts or, the -15 Volts is being dragged down because of a fault somewhere....DAC (unlikely, these are very robust IC's, though not impossible) or an OpAmp.
I can't find (quickly and I've got to go to work now) where the +/- 10 Supplies are derived from on the Servo section. If these are derived from the +/- 15Volts then there may be a problem here however, you say the CD spins OK so very doubtfull.
Seeing as it plays but no sound I'd start with the Audio section.
Can you pull the Regulator and supply the -15 V from a Bench PSU? Carefull to monitor the current here though or you could do more damage than you cure !
If easier, remove everything, one by one, that is supplied by the +/- 15 V untill the -15 V comes back up and you should have your problem......hopefully !
I'd start with the OpAmps.
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Reading 1 :
Kill set at lowest on ddm 200mv : 0.08
Reading 2:
- 1
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Reading 3
An externally hosted image should be here but it was not working when we last tested it.
I am wondering if its the silmicII i put in place of the ES bipolars, but it was working on the spare CD50 board, well there was a buzzing sound, which I think was more power related, than sound😕
Hi Percival
Thank you,
scary then, a bit of cross wire, but it should be fine i hope. no i get no -ve in those readings, i keep the -ve ground on center and measure input and output😕
I am a bit confused, i might try the opamps first as they may not be sitting correctly in the sockets, and use the old dip ones. I already swapped out the regulator from the other CD50 board.
I will do more tomorrow morning.😱 mods and me dont seem to work
Hi,
If the base it is negative means the the kill it is not shutdown the outputs. The reason for checking the kill it is because it is used for mute the output. now that we know that it is not enable we can move forward.
If the base it is negative means the the kill it is not shutdown the outputs. The reason for checking the kill it is because it is used for mute the output. now that we know that it is not enable we can move forward.
Hi Tauro,
Thank you
Yes both readings of the bases were -1
Only the kill was positive 0.08
Hi,
Did you tried to listen using the headphone? The headphone it is driving directly from the D.A.C.
Did you tried to listen using the headphone? The headphone it is driving directly from the D.A.C.
Hi
I have not and dont have a headphone that will fit it plus i removed the variable pcb board and cant find the connector cable, i will take it apart and put old opamp in place
I have not and dont have a headphone that will fit it plus i removed the variable pcb board and cant find the connector cable, i will take it apart and put old opamp in place
still no sound, old op amps in, edit just realised lol, i did not solder one of the opamp in, but left or right channel should have given sound?
Hi,
You I would recommend to try to see if you have sound thru the headphone or try percival007 advice to find why you have -11 volts when it should be -15 volts.
You I would recommend to try to see if you have sound thru the headphone or try percival007 advice to find why you have -11 volts when it should be -15 volts.
Hi Tauro
I will have to find the cable that joins the pcb variable output unless? I can still use the headphone without the grey cable.
Percival adice, yes i changed the opamps, i went to check yesterday and probes slipped a bit and a bang sound, but no burning smell. I never got a negative reading with my meter? unless i put the positive probe on the earth? to get the -ve value, i will pay attention to 6593
I will have to find the cable that joins the pcb variable output unless? I can still use the headphone without the grey cable.
Percival adice, yes i changed the opamps, i went to check yesterday and probes slipped a bit and a bang sound, but no burning smell. I never got a negative reading with my meter? unless i put the positive probe on the earth? to get the -ve value, i will pay attention to 6593
Hi,
You said that you have to switch or swap the probes to read the negative voltage. You should not need to do that reading the negative voltage. You should be able to read the negative and the positive voltage with the negative probe touching a ground point. Double check reading the negative voltage. Make sure your are using a know good ground point. You can use the middle point of any positive regulator. The middle leg of the 78XX normally it is the ground.
You said that you have to switch or swap the probes to read the negative voltage. You should not need to do that reading the negative voltage. You should be able to read the negative and the positive voltage with the negative probe touching a ground point. Double check reading the negative voltage. Make sure your are using a know good ground point. You can use the middle point of any positive regulator. The middle leg of the 78XX normally it is the ground.
Hi Taruo 🙂 Thanks so yes negative probe stays on ground pin, i will see if i get these values again, first i shall check if i am getting sound then, take off the bottom and measure regs again in particular the one Percival mentioned
6590 part number on the board is the hottest reg
+23v in and +15v out
6593 part number last within heatsink at the back, some warmth in it, as well has heatsink, not over the top, 6590 stands out as the hot one
readings are +11 out and +26 in.
+23v in and +15v out
6593 part number last within heatsink at the back, some warmth in it, as well has heatsink, not over the top, 6590 stands out as the hot one
readings are +11 out and +26 in.
6590 (7815) I would say is OK. It has the right Voltages in and out. It is doing a lot of work so will get Hot. I wouldn't worry about this......at the moment.
6593 (7915) Here we have a problem. Positive Volts on the Input and Output ?!?!?!?!?
I think maybe you are reading your Meter wrong or have put the Probes in the wrong place?
With the Negative (Black) Probe on the Outer RCA Connection (0 Volts) use the Positive Probe to measure the Voltages.
6593 Pin 1 should read 0 Volts (it is connected to 0 Volts directly).
6593 Pin 2 should read (not specified in the Manual but with 42 V AC from the Transformer will give around +/- 26 Volts) -26 Volts (Negative 26 Volts).
6593 Pin 3 should read -15 Volts (Negative 15 Volts).
As I say, I think you have been measuring with your Meter incorrectly. Try again placing the Probes as I have said and look at 6593. Are you getting -11 Volts (Negative 11 Volts) at Pin 3 ?
if you are........................read my post #20 again and report back with your findings.
Good luck.
6593 (7915) Here we have a problem. Positive Volts on the Input and Output ?!?!?!?!?
I think maybe you are reading your Meter wrong or have put the Probes in the wrong place?
With the Negative (Black) Probe on the Outer RCA Connection (0 Volts) use the Positive Probe to measure the Voltages.
6593 Pin 1 should read 0 Volts (it is connected to 0 Volts directly).
6593 Pin 2 should read (not specified in the Manual but with 42 V AC from the Transformer will give around +/- 26 Volts) -26 Volts (Negative 26 Volts).
6593 Pin 3 should read -15 Volts (Negative 15 Volts).
As I say, I think you have been measuring with your Meter incorrectly. Try again placing the Probes as I have said and look at 6593. Are you getting -11 Volts (Negative 11 Volts) at Pin 3 ?
if you are........................read my post #20 again and report back with your findings.
Good luck.
Hi Percival,
Thank you for the help. I was using the centre leg on the reg as the negative (ground). I will try them as you said wit the negative probe on the RCA, also will try 6590 again measuring the correct way.
I shall look over this tomorrow morning as the morning light is nice and bright where I sit to do my mods, and report back,
Enjoy the rest of your day, must be around morning there
Thank you for the help. I was using the centre leg on the reg as the negative (ground). I will try them as you said wit the negative probe on the RCA, also will try 6590 again measuring the correct way.
I shall look over this tomorrow morning as the morning light is nice and bright where I sit to do my mods, and report back,
Enjoy the rest of your day, must be around morning there
The Centre Pin of 6590 is 0 Volts and can be used as the reference, but, it's easy to slip off this pin while concentrating where to put the Positive Probe. You can slip off and short circuit something causing more damage !!
I find it easier to put the Negative Probe somewhere where if I slip, it won't do any damage, the outer connection of the RCA Output is a good place to use I find.
Yes, morning here, nice and bright in my workshop (small shed!!) this morning.
I find it easier to put the Negative Probe somewhere where if I slip, it won't do any damage, the outer connection of the RCA Output is a good place to use I find.
Yes, morning here, nice and bright in my workshop (small shed!!) this morning.
Hi Percival,
I had to fix my DDM lead this morning, and now i used the RCA as the earth as you said.
taking pin 1 from the input ( facing from front of unit)
6577
1: + 40.4
2: +14
3: +29
6592
1: 0
2: -12
3: -6
6590
1: +23
2: 0
3: +15
6593
1: 0
2: -26
3: -15
6591
1: +11
2: 0
3: +5
I might try to see if i am getting sound, least 6593 seems good now
I had to fix my DDM lead this morning, and now i used the RCA as the earth as you said.
taking pin 1 from the input ( facing from front of unit)
6577
1: + 40.4
2: +14
3: +29
6592
1: 0
2: -12
3: -6
6590
1: +23
2: 0
3: +15
6593
1: 0
2: -26
3: -15
6591
1: +11
2: 0
3: +5
I might try to see if i am getting sound, least 6593 seems good now
All those Voltages appear good to me now. What did you do?
Perhaps it was your DVM Lead giving odd readings now and again?
So, do you have sound?
Perhaps it was your DVM Lead giving odd readings now and again?
So, do you have sound?
Hi Percival 🙂
All i did was put the negative on the rca plug, plus i noticed my +ve lead was almost broken, and i resolded and patched it up 😀
All readings are good, yet no sound, wonder if channels are mixed, though I would stil get sound?
I wonder if the no polar silmicII are suited in the bipolars place, the old cerafines were fine though.
There cant be a broken track anywhere or would show up in voltages unless opamps are the issue? as i roughly threw them in with a bunch of stuff
Do you have an oscilloscope? Are you able to 'scope for the DATA and CLOCK Lines going to the DAC?
If no 'scope, can you take some DC readings on the DAC and Op-Amps?
I take it you've done some Modifications to the player. Can you list what you have done?
I don't think the Silmics will be the cause.
On your Mods, have been over your soldering to look for any solder splashes/short-circuits. It is sometimes easy to do this, especially when you're in a rush to listen to your latest changes. I'm guilty of this too !!!
If no 'scope, can you take some DC readings on the DAC and Op-Amps?
I take it you've done some Modifications to the player. Can you list what you have done?
I don't think the Silmics will be the cause.
On your Mods, have been over your soldering to look for any solder splashes/short-circuits. It is sometimes easy to do this, especially when you're in a rush to listen to your latest changes. I'm guilty of this too !!!
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