On another note, here's a pic of the new modified CFP DOS in the player
Can you please explain the mods you did to the CFP DOS ?
It could be a broken driver IC, it should be moving in service mode, no matter what.
You can test that by swapping two drivers and see if the problem goes with it, if you have no new driver around. But first you should check the voltages at the drivers AT THE PINS to see if anything's missing, like +/- 11V or the 2.5V reference voltage.
Ray
You can test that by swapping two drivers and see if the problem goes with it, if you have no new driver around. But first you should check the voltages at the drivers AT THE PINS to see if anything's missing, like +/- 11V or the 2.5V reference voltage.
Ray
Same as Brent Ricardo, CCS replaced with original resistor, all FETs and I used mica caps and uprated coils on the filter.As I say, Brent went through it all on here a few weeks ago. I will replace those ZA's with BG's as soon as I get time to recover a few!!!
Hi Ian,
How do you like the sound of the 'new' DOS?
Ray
Thank you UV101
I know what brent did. Did you experiment also with the jfet CCS ? If so what are your subjective opinions ?
I agree with you that BG sound better than ZA in the DOS... But then also do Silmics II
I've not tried so far. Been a exceptionally busy again. I will get round to playing with the DOS configuration eventually!!
Hi Ray, the player is not quite right yet. This build is from scratch and so there is a lot going on and many new components. I'll will say it sounds very promising. Very detailed and dynamic. definitely lost the harshness I didn't like in my previous builds. As you know, I have one of the last original DOS boards too. In time I will test back to back with identical PSU and report.
Well, I would leave Q105 in there for now, it looks like supply problems to me. Do you still have the 4.7 ohm resistors in place, in series with the supply-lines? If so, you should check them, they may be open. The supply-voltage should always be there, whether the IC is broken or not. The Vref voltage doesn't come from Q105 but is external, it is generated near the servo IC by voltage divider R124/R125. It could be the 5V through R122 is missing. Hope this helps!
Ray
Hi Ray, the player is not quite right yet. This build is from scratch and so there is a lot going on and many new components. I'll will say it sounds very promising. Very detailed and dynamic. definitely lost the harshness I didn't like in my previous builds. As you know, I have one of the last original DOS boards too. In time I will test back to back with identical PSU and report.
Sounds good, do keep us posted
The board has two holes, between the output capacitors, that you may use. But you can also mount them on the metal HDAM cans with some double-sided tape, this works very well. The entire board consumes about 40mA max. with standard 78/79xx regulators in place. If you use shunts, the current will be larger.
Regards,
Ray
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Thanks Ray, i don't know why R124/125 has gone missing . I did some changes about 3 yrs ago but did not pick it up again until lately
Well there i go again, this time the damage is at the connector of the display board. Ham-fisted approach was the killer. The display now reading nothing and nothing is happening.
Should i retire the cdp or hard-wiring the display board?
Any suggestions Ray? I feel so terrible. I even try a donor display panel but nothing lighting up so i presume the connector has been damage or the microprocessor?
Quan
Should i retire the cdp or hard-wiring the display board?
Any suggestions Ray? I feel so terrible. I even try a donor display panel but nothing lighting up so i presume the connector has been damage or the microprocessor?
Quan
That sucks Quan...
It could not be all that bad, maybe the negative voltage for the display is missing because you created an accidental short. Then the display stays dark.
Check for 3.5V AC between pins 2 and 26 of the display (VF1 and VF2). And check for -24V DC between VF1 or VF2 and GND.
Regards,
Ray
It could not be all that bad, maybe the negative voltage for the display is missing because you created an accidental short. Then the display stays dark.
Check for 3.5V AC between pins 2 and 26 of the display (VF1 and VF2). And check for -24V DC between VF1 or VF2 and GND.
Regards,
Ray
Sorry Ray, you are a champ
Thank you
i measured the fuses . They looked good but dead. Put in new ones
display came on . Playing at the moment, too late for sound check . Wife and kids are sleeping.
Many thanks again Ray for your patience and great help in trouble shooting.
I am learning a lot.
Quan
Thank you
i measured the fuses . They looked good but dead. Put in new ones
display came on . Playing at the moment, too late for sound check . Wife and kids are sleeping.
Many thanks again Ray for your patience and great help in trouble shooting.
I am learning a lot.
Quan