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Help with wm-2091/f2095

t2m253 - 2011-07-29 15:55

I got one of ebay for 10 dollars, thinking I could fix it like I have with many others. It powers up and the motor spins, I replaced the belt and it should work fine. However when play is pressed static and bits of electrical screeching comes from my head phones. I inserted a tape and the same noise. Ive spent hours trying to figure out what is wrong with it. the thing I did discover is when I touch the head with a piece of metal (grounding it?) the noise is significantly decreased. Even still, there is no music. I have no idea whats wrong with it, if you have any insight I would greatly appreciate it! thank you!

plop - 2011-07-29 16:22

Screeching noise could indicate expired capacitors. Arm yourself with a ESR meter to test the values of the capacitors. Anything greater than 10 Ohms is likely to be duff. Check for oxidised or corroded solder joints and traces near capacitors as this could indicate the location of the failed capacitors.

bub - 2011-07-29 19:34

All of my 2095 based units have dead surface mount capacitors. There's quite alot of space to work with so re-capping should not be too difficult. Out of the 4 2095 based units I have, 2 have shown signs of leakage while the other 2 do not.

 

Here are the cap values:

 

1x 330uf 2v

3x 2.2uf 50v

1x 3.3uf 50v

2x 4.7uf 35v

3x 22uf 6v

2x 47uf 4v

 

Quite a lot of strange values and cap sizes. Around 5.4 mm height should be good.

I only got one of my 2095 based units to work- a GX50. Sadly nearly all of mine have cracked/severely corroded motors or other random mechanical problems. I had to tear 3 machines apart to make a good one. It's great that yours works!

 

 

They can sound pretty good when fixed though.

t2m253 - 2011-07-30 13:31

thank you both very much i will start checking my capacitors and ill let you know what i find!

mark - 2011-07-30 17:03

that is a helpful list of caps. thank you. i have a 2095 and 3 wm-190 that share the same main board. the 330uf caps on all of them have leaked and don't even do anything anymore. a faint buzz tapering of to this faint clicking and then nothing. planned obsolescence at it's finest. stupid garbage sony. i kind of hate sony in some ways for their tricks. all my pre '90 walkman are fine.

bub - 2011-07-30 19:05

Actually, this is the ONLY series of sony walkman I've come across with bad cases of leaky caps (bar my W800 which im still stuck), all my sony models that come before and after don't tend to suffer from leaky caps that badly (most later sony units seem to prefer using tantalums)

t2m253 - 2011-08-02 18:00

I am attempting to check my capacitors today and am pretty lost at what to do. I have it open with my ohm meter out. I checked them all and it seems that only four are still good (under 10 ohms). it doesn't look like my capacitors match that list either. thanks again!

 

here is my list. with the ohm measurement. none of them were under 10ohms... my meter was off...

 

330/2v-20ohm

47/4v-40ohms

22/4v-1000ohms

22/6v-1000ohms

22/6v(#2)-40ohms

22/4v(#2)-40ohms

47/4v(#2)-20ohms

47/4v(#3)-45ohms

4.7/35v-infinite 

2.2/50v-1000ohms

2.2/50v(#2)-infinite

4.7/16v-500ohms

3.3/35v-2000ohms

2.2/50v(#3)-2000ohms

47/4v(#4)-45ohms

 

 

is it totally dead then? is there no hope?

t2m253 - 2011-08-02 19:13

also I have been messing around with it and it when i touch metal spots "Rch metal" & "Lch metal" to the ground sound comes out... it seems the static is louder than the music and when the static is gone the music comes back... idk what this means but its something new i found.

 

update: now that ive left it on this whole time it plays music with a loud beeping and electrical static that is synchronized with the beeping.

plop - 2011-08-02 23:20

t2m253,

You cannot test electrolytic capacitors with an Ohm meter, you need an ESR meter. ESR stands for equivalent series resistance. Without getting too technical, an ESR meter generates a very low AC voltage (not enough to charge the capacitor) at a known frequency from which the resistance is worked out on the other hand an Ohm meter does not. The readings you have posted up, will have been the resistance around the capacitors in circuit.

Have a read of 9th post down in the link below for more info and links to ESR meters.

index.php?board_oid=193392314111653483&content_oid=217178235650847317

t2m253 - 2011-08-03 00:43

Thank you plop. that article was very interesting! basically my ohm meter did nothing then.. which means there is a chance i can still fix it. i looked for leaky ones and i see one that looks like it leaked and then rusted. i have other walkmen that i use for parts and it has a 22/4v capacitor on its circuit board. the capacitor on the walkman i am trying to fix is in a little black box and the other is not. id like to take the leaky one off and re solder that one on. is this a good idea? 

plop - 2011-08-03 01:06

Without a proper meter to test, it would be foolish to replace a failed part with a questionable part which you may have to replace again in the not too distant future if proved to be faulty too.

 

For a few cents per new capacitor, it would be wiser for you to get some new ones to replace all the duds.

 

In the long run if you intend to repair old electronics kit it would be a good investment to get an ESR meter to probe for dodgy caps. These components invariably are the source of a lot of electronics equipment going screwy these days.

t2m253 - 2011-08-03 01:17

i took the foolish route and replaced it... now the left channel works great! the right still has beeps and such as before. i should invest in one, and some new capacitors though.

bub - 2011-08-03 04:21

Yup, and absolutely replace all caps in one go if you can!

t2m253 - 2011-08-03 04:34

I've replaced five now, and the noise is significantly lower, and non existent in the left channel. however there is still that extremely annoying frequency in the right! I wish it would just work; it's such a tease hearing how crisp the left channel is...

bub - 2011-08-03 07:20

Did you replace all the capacitors with brand new ones? You can get new ones from element14 or Digikey for example.