Hi! Does anyone have tips for repairing my speaker?
I have a Philips NTRX500 speaker that immediately goes into standby mode as soon as it's switched on. I can't get it out of standby because it doesn't respond to any of the buttons on the device. The remote control is missing. I ordered a new one, which should arrive this week. However, it should be able to do everything without a remote control, as it has physical buttons that worked fine years ago.
Now, with the help of AI, I started looking into where the fault might lie. I've ended up at the circuit board and now seem to be stuck in my search. AI isn't a hero and I'm no electrical speaker genius, so I hope someone can point me in the right direction.
The speaker's history: about 5 years ago, it moved to a new house with me. During the move, it got stuck on its power cord, which damaged the connection. My father soldered the wire back on, and the device responded moderately well after that. It would always turn on, but only responded to the buttons half the time. I would plug the power cord in and out a few times, and sometimes it would catch properly so I could use the speaker fully. After that, it moved again and stayed in a shed for 3 years, and now I'm cleaning out the shed. Throw it away or try to repair it? Option two. I'm now at the point where I'm looking for a replacement circuit board and have even found speakers in the US and Germany haha. Sigh, nostalgia.
Anyhow, last week I went to a Repair Café. A gentleman secured the power cable properly to the device again. We unscrewed the top of the speaker and checked: all wires to the buttons are connected correctly and nothing up there seems burnt out. Device turns on, buttons don't respond, the gentleman put a CD in the tray and now can't get it out anymore. Duh. Then at home, I unscrewed the bottom myself. Cleaned the circuit board with isopropyl alcohol. Checked all the cables—looks good. Nothing seems burnt out. Turned the speaker on, and it worked right away!! Buttons worked, couldn't find Bluetooth, played 1 song via cable to my phone—super awesome sound! Dinner was ready, turned the music off, the speaker ejected the stuck CD all by itself, and after a while, it went into standby mode on its own. Tried to turn it on again afterward... Nothing. It turns on, lights turn on, lights go off, standby mode turns on, and the power button stays lit up red.
Help! How do I proceed from here? After a search with AI, I tried several things. The capacitors all look fine. Disconnected the speaker cable, turned the box on, still goes straight into standby. So the problem isn't a short circuit in the speaker cable. AI keeps coming back to an internal protection mechanism: a chip under that big, silver block that might be burnt out or isn't delivering enough power.
In short: who has the magical info to help me on my way? Where can I continue my investigation?
P.S. I don't really dare to measure the device with a multimeter myself. So much can go wrong with short circuits...