Hello to all and many thanks for this forum.

I acquired a Walkman Pro WM-D6 recently and it had a few problems. I've been able to fix them all aside from one. I was hoping somebody could help point me in the right direction as to how to fix my last prob:

The peak indicator LEDs will not light at all under any circumstances. When the switch is turned to BAT the bottom LED lights up. I tested each LED and they all work so I'm assuming that the audio signal is not reaching the LED board or that a component on the LED board has gone bad...? Something like that?

I have the .pdf version of the service manual but am having a hard time deciphering the schematics. It's been 20+ years since I've worked on circuit boards so I'm really, really rusty.

Any suggestions?

Many thanks!

TLP

There are several wires going from the Main board to the LED board, including from the Line Amp. Check those out for continuity first. Depending on revision the wires are numbered differently in the Service manual.

You can find the main board revision no. on the printed side for the early series and the component side for the later ones. eg. 1-611-494-11.

Thanks for answering my post, bub.

The wires going from the main board (early rev.) to the LED board are all good. No resistance at all. I tested that power is getting to the LED board and it is. Every wire in the schematic is going from the main board to the LED board just as shown in the service manual.

I've checked for dirt build up (I'm the only one who has ever taken the wm apart), grease or grime...anything that could be causing a short and haven't found anything.

Is there one specific area that I should be focusing on that has been known to cause this kind of problem before? Have you ever heard of this problem before?

Thanks again for your reply!

I finally found the problem: IC801 on the LED board. I used a tiny keychain amplified speaker to trace the signal since I no longer own any decent troubleshooting equipment. The signal was fine going in to pins 2 & 3 but the output on pins 9-13 had too high voltage output to light the LEDs.

Hopefully this thread will help somebody else out in the future.

I have one more question: Where in the world do I find such an old IC chip without having to buy another Walkman Pro?! Anybody?

here ;

http://www.alibaba.com/showroom/ic-801--.html

  or here

http://products.pacparts.com/i..._xma1_1101039175.php

http://products.pacparts.com ic_ref_ic801_xma1_1101039175 php

Thank you, traveler, but I think I must be missing something here. The chip is labeled IC801 on the LED board but it's printed as TA7654P. That leads me to a Pioneer chip.

How can I be certain that I'd be ordering the correct chip for the Sony WM-D6 LED board?

Again, sorry. Like I said it's been about 20+ years since I've done any troubleshooting down to component level.

well  I  have 2 of each D6 & D6C each is a backup for the other and

That makes sense.

For me, though, I don't want to invest that much money into this. I think I'll just sell this one on eBay "as is". Wish I hadn't slipped with the soldering iron on the body though. argh.

Thanks for trying to help. I appreciate it.

hi !
I do have a sony d6c (awaiting for repair since a few months !!)

and I think I have the same kind of problem.
My ic801 is a cx10043 which is unknown everywhere ...
I do have a single led in "batt" mode (with 6V in, I was hoping all 5  on )
in "peak", I have only one led blinking with the music.

Could someone could confirm the batt position for the led ?

thanks ...

Here is the operating manual for the WM-D6C:

http://www.educ.cam.ac.uk/serv...Sony-Pro-Walkman.pdf

On page 4 it says that only the bottom LED should light up when the switch is in the "batt" position.

As far as the LED driver chip you have, I don't know if it's the same one as the WM-D6 or not. Maybe somebody else can answer that by looking at their unit?

Hope that helps.

Confirmed in Pictures

Sony WM-D6C Recording Cassette Walkman Battery strength LED 1 Bright Winding
 

Sony WM-D6C Walkman Five LED's Peak Level Playing Album w 4 out of 5 showing

hi
and thanks for those details
According to the problem in "peak" mode and regarding the single led in "batt",
I was assuming my cx10043 was destroyed !!! (and irreplacable)
so my d6C was just waiting

To TLP :
so we have the same problem
but YOUR led driver is avaible at low price
http://www.ebay.fr/itm/TA7654P-Integrated-Circuit-x-1-pieces-/400360925595?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item5d375ee99b
http://www.ebay.fr/itm/IC-TA7654P-5-LEDs-Driver-LED-Treiber-/380249068629?pt=Bauteile&hash=item58889c5455
BEFORE buying it , let's try to investigate further , just to be sure ..
As the only problem is now the "peak" mode to be very low (only one or 2 led) ,
could anybody who owns an oscilloscope try to mesure the signal at the output of the line amp IC301 njm4558 ?
Thanks anyway to TLP for the information about TA7654P ,now I have an "equivalent " of my cx10043 (not for the pinout) so I can understand better .

personnally, I only need to replace my servo driver cx20084 which is 5e on ebay !!

in anycase, the led problem is just a disply matter , the rest of the machine will be ok
so I will keep it even if we can not solve the led problem
because from what I have heard so far , the sound is great
I am looking forward to replace my cx20084 so I can do my first record

regards

Okay, if we're going to solve this problem, let's solve it.

I did see that TA7654P is available from China, U.S.A., and U.K.. I live in the U.S.A. so I went ahead and ordered it from here. If it is shipped as promised I should receive it sometime between May 1st and May 3rd. Then we'll know for certain if that is the problem with my LED display. I'm betting that it is.

You're right, an oscilloscope would come in handy! I used to have one but it's long gone now so here is what I did to check the output to the LEDs from the pins:

I used a really junky little multimeter and tested output on pins 9-13 (TA7654P) while the unit was in "batt" mode. I noticed that the output on each pin was between 5 - 6V DC with the exception of pin 13. Pin 13 had a very, very small amount of DC V output which allowed the lowest LED ("batt") to light up. I then tested the output again while the unit was set to "peak" mode and found that ALL of pins 9-13 showed 5-6V DC output so weren't able to light the LEDs at all. So, that's what leads me to believe that the signal is not making it through the chip as it should. Or coming out the other side in some strange wave patterns (which is exactly why an oscilloscope would be most excellent to have but I am not rich. ha!).

In your case, it sounds like you are getting a somewhat "normal" signal out of at least 2 of your pins but w/o an oscilloscope who's to know for sure? Maybe you can try what I did and see what DC Voltage your pins are outputting in both "batt" and "peak" modes? It's worth a try if you haven't already tried it already.

In any case, I have ordered the chip and I will let you know if it fixes the LED "peak" problem as soon as I receive and replace it. And hopefully this will help many more people in the future who come along with the same problem. 

I really have no need for my WM-D6 which is why I'm probably going to sell it. I'm glad you have good use for yours!

wm-d6 Peak Indicator LEDs don't work?

Confirmed in Pictures

Sony WM-D6 Recording Cassette Walkman Battery strength LED 1 Bright Winding

Sony WM-D6 Walkman Five LED's Peak Level Playing Album with All 5 showing

Non Dolby ( C ) model  had to take quite a few picture's to ketch that last or Highest LED peaking   

Hope you get the IC replaced and the Leds repaired... It's very useful when making recordings.

It's a shame Sony never re-designed the LED circuit to use all 5 Leds in BATT test mode like the D3.

Also, glad to see the use of eneloops in a D6C... the new generation low self-discharge NIMHs are incredibly convenient, as walkmans like the D6C drain batteries like mad. With the smart charger it charges nearly as fast as most modern electronics. (Plus they don't leak!)

Is a good read here below link ( about D6C & D6 Sony Walkman WM )

 Is it all in your head?

 http://REPLACEMENT ERROR/topic...-in-your-head?page=2

Second page has best info

about the serial number's an what they refer to what revision of above model's

hi
I finally had the time to make a few measures on my d6c

the led board is feeded by audio signal by 2 wires
no 1 yellow
no 2 blue

I changed my reading tape to be sure it is recorded in high level
and this time I reach 3 led
both wire carry music signal at a level of about 1V peak to peak
(seems a bit more sometimes, not easy to see at the oscilloscope)

anyway the led board audio signal comes directly from the line out jack and the volume pot
So if you have sound in there you should be worry about the led chip itself
(did you check its power supply via Q801 ? mine is ok at 3.20 V)

In fact, my walkman is disassembled for such a long time
I forgot the graduation on the front side
3led indicates 0db so it is ok for me I suppose
Still waiting for my cx20084 to confirm everything...

be in touch with us if you receive your chip

regards...

Does the humming get less when you turn Dolby on? All my d6's have some kind of motor hum when the volume is maxed and Dolby is off.... 

I haven't been able to try Dolby on/off in regards to the humming because when I sat down to try switching it on/off the Play and Record buttons no longer work. I can ff and rewind but Play and Record don't work. When I try to Play and/or Record the motor is running but not turning the spindles.

This D6 is the gift that keeps on giving! Arghhhh!

So, now I have to figure out what this new problem is.......?

As far as the humming goes, it was really loud so it's probably not just normal D6 humming. It will be a miracle if I ever get this thing fixed!

The humming should not be so loud. Better to check the grounding of the motherboard again. Have you used al the motherboard mounting screws? You could check if the traces on the dc-dc board arent touching any chassis parts. Happend me before and it gave a hell of a hum with plopping noises!.

If its not playing and the motor is running it should eat tape... Except if the roller isn't pushed against te capstan. In that case there is something with the pause button. You can adjust it. The service manual says how to do it. 

My d6's are the same... A never ending story... I hopped over to the D5 types for my recordings...

Hello to everyone !

I did change my cx20084 and speed is ok

I have an other problem on this d6c : the battery clip

it is supposed to maintain the battery in place so it can not be ejected.

This clip is ref 9 -10 -15 in the diagram od the service manual

but mine does not hold anything, and battery is always free

Could someone send me accurate photo of what this clip should appear like from the outside ?

thanks