On flea market i purchased some beat up deck. It was cheap and seller convinced that it turned light on batteries. But it appeared to be in really rough shape. First what i noticed that batteries got stuck in their compartment. And it doesn't even get led light all unit remained silent. So i decided to open it up and it appeared that big red wire was "solder" to 3v line i switched it up for smaller one. Still no signs of life. I thought to give a try and desolder every wire to leave direct connection with batteries and motor. Firstly there was no sights of any movement but i lubed motor and it started to move Hooray! Sadly when i plug everything on motherboard it doesn't work. I read on this forum that this DD line of walkmans needs to replace capacitors so i ordered a new repair kit from fixmyaudio. Waited a bit when it arrived i replaced every capacitor on board it was a good call because every cap on board leaked. i put everything on and tried again. Still nothing ;/. I also de soldered some extra wiring from "processors". So i dont know what's going on with this unit i noticed some bubling underneath battery traced connection so i scraped a bit of coat and it loooked ok for my eye there is still connection but maybe its too weak ? Batteries gives 2,5v on this. I have no experience in that deep maintenance field but maybe you can help me. I not am sure if i put proper one in place of 10 16v cap for 4,7 16v i mean about these 2 caps on bottom from first left picture. I added photos from in i think order before changing caps and after. https://imgur.com/a/dd11-106syqw
My browser blocked me from viewing your picture. I don't suppose you could upload your pictures directly to your thread here so we could view them
Well uploading photos to this site doesn't worked for me so i made a hyperlinks with so all should be visible anyway. I tried to probe some of traces on board and seems like almost everything got connection but FG line closer to + of motor doesn't get any but when i measure ohms of this 2 wires it gives about 720 ohms
I don't think I have ever measured the ohms of a motor. I have always put electricity through it to make it work but never measured the resistance of a motor because it's constantly changing because it rotates and moves. It's not a static device that's interesting Ps I took a moment and scrolled up and for some reason or another yesterday your pictures did not appear via the link but today they automatically are populated in your link because I scrolled up after I posted my above. So I'm going to go back and look at those pictures now
@RedHackeT For uploading photos, keep in mind there is a size limit of 2000 x 1600 pixels and 10MB. In many instances you need to resize the photos to be uploaded here. It's also a good ideal to upload images as Thumbnails rather than full images since it's hard to scroll through images that occupy more than a whole screen. There's also the option to upload the images just as attachments, without being thumbnails or full images, which is useful if you have many of them. In regard to the problem of motor not running, there are a couple of things to check: - does the power LED light ? - do you get any noise from the headphone output (turn volume at max) ? Assuming the board is powering on: - do you get any voltage from the motor servo ? - does the motor run if run on a 1.5V battery ? The FG coil resistance of 720 ohms sounds about right. Although have not measured it in this walkman series, it's in the ballpark I would expect it to be.
No light like i said also no noise but when i plug jack i hear small pop on speaker. I measured few things from red circle there is only some low voltage in 1 and 2 Left and Right 0,018V but only when its not plugged with jack. On Green one i measured and it gave me -2,75V across testing bottom board but there are some spots when i measured from green circle to blue one first gave me -1,84v second -2,3V third -2V and whole 4 almost 2,34V.
Hi ..and I've been watching for a while ... I don't know if you've seen this part of the circuit ..basically when you supply the 3 volts with the batteries (Red wire) they pass through the external power socket and arrive directly on pin 8 of the famous CX20084 IC601 ...at the same time (green wire) the 3 volts also arrive at the S303 switch and crossing it they arrive on the Q301 .... on the other pin of the q 301 you should have the 3 volts ... which you will find on pin 7 of the cx20084 and through the Blue wire on the rest of the amplifier circuit ... if there are no 3 volts after the transistor nothing works.. I hope this can help you solve another thing using 1.2 volt x 2 rechargeable batteries .. you are at 2.4 .. 2.5 Volts and for the circuit you are at the limit of switching off
Oh and now we are getting somewhere, i think we have a main suspect of this transistor pm q301. I measured on other side of pcb and you can see most of the board doesn't have any power just some around battery and nearby switch s303. I measured that lines what you mentioned and s303 doesn't get any power but from q301 goes something like 0,36v to the 7 pin of chipset. So i think i need to replace that transistor but what should i get when i google that part goes nothing and there are many smd transistors to choose from. Anyways thanks for helping ;]
I took your photos again and on the red points there must be 3 volts of the battery (on the transistor it arrives by connecting the leaf switch) ... on the green points the 3 volts after the transistor ... I noticed a strange connection on some photos that should not be there ... red wire and then yellow that connects to the cx 20084 ... you risk burning something
Well I've seen some folks had same connection with red yellow wire in thier dd11's so i first left it intact and then de-soldered but i soldered again and yea it looks quite odd so i removed that again. Anyway i measured again and red one gets only -0,4v the right one gets 0V, Greens gets nothing. Speaking about DC power socket i thought i had cold joints so i reflowed that but yea contacts inside looks rusted as well. There is signal from it so i don't know. But the most unusual thing that there was a wire from battery contact to other side. Maybe its only that transistor Q301 or maybe its more so far this one is main suspect
So looking at the photo I posted before, try connecting the positive pole of the battery directly to the transistor... on the pad where the blue wire is connected... in this way you bypass the external socket and switch s303... and measure the green points...
I looked over these green spots how you described and yea this is busted transistor with direct connection of battery it gives only -0,001v for that small capacitor and cx chip on bigger cap gives nothing. So what type of transistor it is like mentioned googling this part from service manual gives nothing particular. edit. i think i found what is that B7 transistor. Im waiting for parts to arrive from China ;].
I received transistors from Ali and i replaced that. Sadly only 0,236v goes through s303 switch when i measure from - point of batteries bracket. But when i plug + side of battery directly to transistor interesting thing happens. I have low value for green points but on cx chip there is -0,8v and i can hear crackle when speaker is connected also led is lighting so we are getting somewhere.
But I already knew that it wasn't the transistor... you have a short somewhere after the transistor that absorbs a lot of the energy if you connect the 3 volts on the transistor and on the green points they don't appear... and also on the CX... only 0.8 volts... there is some component that is not working or simply some connection almost shorted... then since nothing comes from the batteries when it is connected normally, replace the external socket or if you can repair it
