I have a boombox Philips AZ-2025,with a defective open close switch that stops it playing,it says open on the front display when the CD lid is closed? Can I short the switch by soldering a bridge across it so that it thinks its closed without it affecting anything else? I cant find a service manual for it let alone a switch.LoL If anyone has any-other ideas how I can go about fixing this I'm all ears!
I'd guess it uses a leaf switch, and if it isn't bad you've likely got a mechanical failure. You could locate the switch and make a permanent NO or NC fix.
Does that affect anything else? It makes the player think the tray lid is always closed, and everything that goes along with that (e.g. there's much less protection from the laser, so keep eyeballs at a safe distance and angle).
Does that affect anything else? It makes the player think the tray lid is always closed, and everything that goes along with that (e.g. there's much less protection from the laser, so keep eyeballs at a safe distance and angle).
A switch is about the simplest logic device. You may have to pull up/down a controller pin through a resistor.
I've never encountered the problem you describe, but on the face of it the solution appears to be just an interlock defeat. Surely possible, but generally frowned upon for obvious reasons.
I've never encountered the problem you describe, but on the face of it the solution appears to be just an interlock defeat. Surely possible, but generally frowned upon for obvious reasons.
I encounter bad switches in CD transports often enough. Door sensors may be more for boom boxes, but in deck types we use in pro audio - DJ rigs mainly - I might have to fix tray in or out limit switches or home position switch on the pickup, or pickup up or down limit.
SOme are open blade, but there are many forms of very timy microswitches too.
I just had a TASCAM deck that sent the tray out and immediately brought it back in. One of the tray limit switches worked electrically, but the actualtor was just barely making, so often the switch actuator did not get fully pushed. I would up unsoldering the tiny microswitch and putting a thin shim under it to bring it up enough its little plunger would go fully down.
Open blades can get electrically dirty or bent or just break off.
If shorting your switch makes it work, then get your ohm meter on it, and see if you can get the switch to open and close by pushing whatever actualtor it has mechanically. You might be able to fix it similar to my shim. It might be cleanable. And if the switch really is defective, you might find one like it in a dead boom box.
SOme are open blade, but there are many forms of very timy microswitches too.
I just had a TASCAM deck that sent the tray out and immediately brought it back in. One of the tray limit switches worked electrically, but the actualtor was just barely making, so often the switch actuator did not get fully pushed. I would up unsoldering the tiny microswitch and putting a thin shim under it to bring it up enough its little plunger would go fully down.
Open blades can get electrically dirty or bent or just break off.
If shorting your switch makes it work, then get your ohm meter on it, and see if you can get the switch to open and close by pushing whatever actualtor it has mechanically. You might be able to fix it similar to my shim. It might be cleanable. And if the switch really is defective, you might find one like it in a dead boom box.
Ive tried a solder bridge(no go) toggle switch(no go) I would try and fix the actual switch but I cant work out how to get it out without destroying everything? Whats this pull up/down resistor about? My problem is I cant work out why if the contacts are closed it completes the circuit,but it wont work,the spindle turns,the laser can focus, the track number is displayed but it wont start to play? Am I missing something ? Ive pulled this thing apart to see if there is another switch somewhere connected to the lid? When the switch is pressed down it clicks and stays down,click again and it comes up,does anyone know why it wont work with the circuit closed? If I fix the switch its still not going to work right?
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Hmmm... so you've checked that there isn't another switch or phototransistor or?
A pull up/down resistor is just a way to confirm a logic level, e.g. a logic low enable pin with a resistor tied to ground is forced to the low state, instead of maybe just floating indeterminately or what I'll call a soft logic low. The resistor pulls the pin voltage down.
It looks like I've been able to download a Spanish-language service manual for your boombox. I'll try and see what's going on. Hang loose though, I may not get to it until later. It's on the upswing of 2AM here.
A pull up/down resistor is just a way to confirm a logic level, e.g. a logic low enable pin with a resistor tied to ground is forced to the low state, instead of maybe just floating indeterminately or what I'll call a soft logic low. The resistor pulls the pin voltage down.
It looks like I've been able to download a Spanish-language service manual for your boombox. I'll try and see what's going on. Hang loose though, I may not get to it until later. It's on the upswing of 2AM here.
Expanding on Enzo's question, did you check the switch action? If the switch failed shorted, and the action needs to be open, all your repairs would be for naught as the shorted switch will bypass everything else.
From what I've gathered through tired eyes, it appears the switch may need to be normally open for playback.
From what I've gathered through tired eyes, it appears the switch may need to be normally open for playback.
I did think of that and I toggled the switch to closed and quickly back to open but it didn't make any difference, I checked the obvious resistors around that area of the board for faults, Ive uploaded a few photos of the switch,there is no way I can repair it.When I tried with the toggle switch it looked like it was going to work but it failed at the last moment,I have an identical one and in comparison it has the right sequence but just wont play.it has a timer on the display but it has only dashes instead of numbers starting with 000 Looks like Ill have to find another switch for it and hope that it will work?
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I followed the circuit back from pin 12 of the micro-controller to pin 2 on the ribbon connector to the laser via a 10k ohm resistor? Ive put the toggle switch back in after I took it all apart and checked that the ribbon connecters ect...were seated properly. Now it starts to spin up and slows down then spins up again,there is a scraping noise when it spins up and it finally says no disk and stops.The lens is clean and not scratched and Ive lubricated the transport rails with lithium grease. I measured across the switch! It measures 5v when off and 0v when its on? When the toggle switch is on(without power) it measures from pin 6 (on the schematic)to the switch tab 976 ohms and the other tab, 976 ohms,with the switch off its measuring it the same as before, its 1020 ohms x 000 ohms Does that make any sense to you?
That doesn't sound right, unless you sidetracked onto a 5V rail. My pics were the 2 ends of the door switch circuit.
It's beginning to appear that the door switch issue could be a symptom of a bigger issue.
I took the switch measurements off the switch itself? Are you sure its the right schematic for this model? I know that different countries have a different prefix on the model number but that would be mainly for the power supply I would think.Could you email me the schematic to ross.dalrymple@hotmail.com ? It looks like I can get another new switch for it but I want to be sure that's all the problem is? When I was taking the switch measurements I was getting 5v on one side and a low reading on the other side (as now I know it should be) and took that to be ov.
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Ive had another fiddle around with it and it started working (playing a CD)as per normal but that was just the once? It will go through the right sequence of the laser search and then its at the right speed for a few seconds,I press play and the display shows its ready to play track 1 until it displays NO CD? Ive noticed the low battery indicator flashes a few times as well, although I'm on AC? I may have to extend the power and speaker wires to separate the bottom from the top so I can take measurements when it is on,unless someone knows the answer to my problem beforehand?
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