Kostgeor Publish time 2020-10-11 08:39:32

Sony d-808k won't power on

Hello everybody! I recently accuired a new discman, the d-808k. The seller said that the unit operates normally except for the headphone out that was very silent. (headphone capacitors, easy fix). He also mentioned that the screen and buttons were not illuminating anymore.
That's what the seller said.
The truth is that the unit has no power at all, or at least, sometimes! I plugged the DC IN jack, pressed play, but nothing. After a while, I pressed the play button again and the unit worked fine. Aprox. 10 minutes after, the discman shut itself off for no reason. After that, it will not power on again, unless you wait for 30 minutes or even more. With batteries the problem is even worst. Most of the times it will not start. IF it starts, then it will stop again later in totally random times.

It is more than a week now that I can't power on the unit, neither with DC IN or batteries.

What I did:
replaced all the capacitors, it didn't helped.

Cleaned the pcb and checked for damage from leaking electrolyte, it was a very clean discman.

Had any of you experianced any similar problem before?
Is illumination problem relevent to this?
Any help or advice will be greatly appreciated, and sorry for my bad english.
I hope that's enough information to let you understand my problem.
Thanks,
Kostgeor.

kaosun Publish time 2020-10-29 09:16:03

Pls download service manual from us and check CPU power supply circuit.

Kostgeor Publish time 2020-10-31 09:08:53

Hello and thanks for the reply.
I checked the pin 34 (VDD) of IC801. According to the manual, this pin should have 3.3v but in this case it has only 0.8v. Every pin in the system that has to be 3.3v is 0.8v. I also checked the IC803's pin 2 and 3 voltages. Both pin 2,3 have 0.8v and not 3.3v. Furthermore, I checked IC401's pin 2,3 voltages. In pin 2 there is only 0.8v (normally 3.4v). In pin 3 (normally 3.1v) there is 0v! I don't know what else to check in the CPU's power supply. I hope these readings tell you something. What can I check next? Thanks a lot!

kaosun Publish time 2021-01-14 11:16:10

In your case, you should check IC401 which is powered by D407. Also, the D407 is directly from battery terminals.

cxlmichael Publish time 2021-04-16 01:53:39

:):):)My D808k have the same question like you,see Mr.kaosun can help us to save it?

kaosun Publish time 2021-04-16 15:27:38

Yep, you can follow the instruction I provided to find the broken points, or ship it to me for repair. THX!

LilSilverBullet Publish time 2022-04-04 14:11:07

Mr. Kaosun. I just got a good condition D-808K, but the headphones out volume is one sided, low and scratchy.Is this symptom of bad headphones out capacitors?I actually have another one but that one wasn't turned on at all.

kaosun Publish time 2022-05-08 20:32:17

LilSilverBullet replied at 2022-04-04 14:11
Mr. Kaosun. I just got a good condition D-808K, but the headphones out volume is one sided, low and...

Yep, ordinary caps' issue.
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