D250 power problem

komodo

My D250 works well with battery (I made a 3D printed case for two 3.7 ICR10440 batteries).
But it does not work with 9V power. It turns on for a fraction of a second, but turns off immediately. The adapter is a genuine Sony adapter that came with the D250.

Where should I look? Can you help me?
Thank you.

kaosun

There's a diode in power supply circuit is broken, it's quite common. Let's see whether you can find it? You can short it by a tweezer to confirm, then replace it.

komodo

Is it D401?
I managed to fix a power problem with my Discman D-150 by replacing that part.

This time, the behavior seems a little different with my Discman D-250.
I’m going to try to find it this weekend! I hope you can give me some feedback. Thanks!

kaosun

Usually D401 and D409.

komodo

Thank you! I will check D409 this weekend.

I am just an electronics hobbyist (I started tinkering during the pandemic lockdown).
Does the part, Q417 go bad too? I was measuring voltages everywhere and noticed a big drop here. I have included a picture of my notes.

I really appreciate your help. Thanks!

komodo

I replaced the part Q417 for my Discman D-250, and it is working perfectly now.
I have another D-250 with power problems, and that was fixed by replacing the diode D409.
Thank you for your advice.

It powers on fine now, but it’s not playing CDs. When I press play the disc spins, and the laser goes up and down (making a clicking sound each time), and turns off after 15 clicks.

I have measured the laser diode emission, and the it is within range. When I try to play CDs in service mode, it spins up, then it immediately spins backwards at a high speed. Can you give me some advice?

kaosun

Spins backward is weird. Can you replace the MPC1715 for a try? Or, in normal mode, increase the laser power to try. it seems like a laser issue? Since you have a working D250, you can swap their laser to confirm the issue.

komodo

I have never replaced a part (MPC1715) that big. I’m watching YouTube videos to learn now.
Before I attempt to replace that part, is there a way of testing it to determine if it is faulty?
What causes a chip like that to become damaged?

Since it seems like the easiest thing to do, I will try to increase the laser first. Just to make sure, do I increase the laser power by turning the knob in the picture? Do I need to turn it counterclockwise to increase the power?

Thank you for your help.

funbear

Hi Mr. Kao,

My D-25 when plug-in power, spindle motor spins slowly/weakly and then stops (laser did no move). the LCD lights on and never turns off. Battery operation on this D-25 has no issue. Another D-15 can only operate under battery, it does not even turn up with a plug-in power.
Are they all same D401 or D409 diode issues? when you said short the diodes, do you mean by shorting S pin to ground pin?

Gwent

komodo replied at 2022-10-08 01:54
I have never replaced a part (MPC1715) that big. I’m watching YouTube videos to learn now.
Before I ...

I think you should CCW and check the current through it, I saw that the current is about 38.3 +6/-11 mA is fine. in this case you can increase the current about 42 or 43 mA I think it fine.