Pin 15-19 to chassis ground 15V. Relais has been worked on with sandpaper at the contacts and contact spray. Looks good. Trafos were powered from external AC. Same behaviour all the time. At about 20° with AC unplugged for a while it starts. At 25° also AC unplugged for a while it never starts. I ordered FM260N now but this will take up to 4 weeks (Aliexpress).
That +5V STB rail is used extensively inside the whole unit.... even for USB-powered devices and for LAN IC's. It might be worth checking if you have anything plugged into the USB port.
I did not expect that the new NTC was going to make any difference. There might be some current limiting happening inside that IC.... or somewhere else...
You'd need to capture the voltages when the unit powers up okay vs. when it fails.
You still may have a cold solder joint somewhere... I explained this in one of my previous posts... and asked for well-lit, in-focus, high-quality photos.
I would try with an external source of +5V _STB... if I were you...because you either have current limiting inside that IC (DIL8 is insufficient for long-term reliability... I suggested a little heatsink on top), or a cold solder joint; a circular crack around one of the pins... that contracts when cold and provides good contact, but then expands when hot and causes a high contact resistance -> and the subsequent drop in current. So yeah, you will get +5V _STB ... but it might not be of sufficient current capability to deliver what's required when the unit is hot.
... if you want to see where that +5 V is used, search the schematics for V+5R0_STB, V+5R0_ST and V+3R3_ST. All of these points are supplied by that SMPS. Just keep in mind that each full page of the schematic diagram consists of 2 x A4 pages in the PDF... a pain!! I'd combine the relevant A4 pages into a single A3, and then print all A3 pages.
Good luck
I did not expect that the new NTC was going to make any difference. There might be some current limiting happening inside that IC.... or somewhere else...
You'd need to capture the voltages when the unit powers up okay vs. when it fails.
You still may have a cold solder joint somewhere... I explained this in one of my previous posts... and asked for well-lit, in-focus, high-quality photos.
I would try with an external source of +5V _STB... if I were you...because you either have current limiting inside that IC (DIL8 is insufficient for long-term reliability... I suggested a little heatsink on top), or a cold solder joint; a circular crack around one of the pins... that contracts when cold and provides good contact, but then expands when hot and causes a high contact resistance -> and the subsequent drop in current. So yeah, you will get +5V _STB ... but it might not be of sufficient current capability to deliver what's required when the unit is hot.
... if you want to see where that +5 V is used, search the schematics for V+5R0_STB, V+5R0_ST and V+3R3_ST. All of these points are supplied by that SMPS. Just keep in mind that each full page of the schematic diagram consists of 2 x A4 pages in the PDF... a pain!! I'd combine the relevant A4 pages into a single A3, and then print all A3 pages.
Good luck
Thank your very much for all good support. I will replace the IC and if this does not help I'm done. Maybe there is less current somewhere or a cold solder joint (but I already soldered a lot of the board again). Nevertheless, mainwhile too much effort for a device I'm not really often using. Keep you updated.
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That effort should be viewed in context "can I fix it or not?".
Usability wise - buy yourself some bluetooth receiver and stream to it from your tablet or phone whatever you want. These N-50 type network players (of which I own one and still keep in living room) are already extinct dinosauroses
IC exchange does not fix the problem. So I'm done. Sometimes the device comes up, sometimes not.
Sorry to read this. Just do not throw the player into dumpster - it can still be a useful spare part donor.
Hello friends! I read all the posts and I guarantee that it was really cool to see how passionate we are about technology and how much we like our audio components. I have the same problem as you, and here in Brazil we have had intense summers. My N-50 also had the problem of not starting after a few seconds of the blue LED on the ON/OFF button blinking. Pioneer should provide more support, even with discontinued equipment, which does not have a similar product from the same brand. In any case, please do not discard your equipment. I'm also going to start some research and start spending time trying to find the problem. This is now personal!!! I don't know what the end of the story will be, but my N-50 looks new and I always leave it on so my wife can listen to her radio. I will do my best to find the defect and let everyone know! A hug and take care!
