Casio AP-60R not functioning

[Trebor51]

I have a Casio Clavia AP-60R that I purchased secondhand about 8 years ago and it has just gone dead. It has the main power light on and the speakers punch up each time I switch on but no power to the display or other buttons. I have replace a fuse on the main PCB and have tested the transformer and it looks to be working ok although one of the secondary orange wires has a lower voltage. I have with closer inspection now noticed that two diodes connected near the fuse that blew have a crack in them, so I am assuming that they are the cause? They have no ohms reading but I don't know if they are supposed to. I left off the earth from the main PCB to the transformer and switched on only to trip the fuses in my house? I placed the earth lead back onto the transformer and switched on again and all was well but still not working to the display. So the power shortage is going directly to earth when it can without shorting out my house.
I tested some other diodes on the board and they all read about 0.56. Also I have noticed that several of these diodes have red markings by them along with a couple of resistors so I am wondering if this might well have been a problem before and it has already been repaired once before. If anyone has any further information that I can use I would be grateful. I am waiting to obtain some replacement diodes that I found on ebay and when I get around to replacing them I will post to let others know how I went>

 

[SeaGtGruff]

I don't know whether you already have the service manual, but if not, you can download it for free online:

https://elektrotanya.com/showresult?what=casio ap 60r&kategoria=&kat2=all

 

[Trebor51]

Yes, I managed to download a copy. Thanks. Very helpful to know the schematics.

 

[Gabs258]

Hi Trebor51,
Were you ever able to resolve this issue? I’m having a similar problem with my Casio AP-60R where the power is on and there is static through the speakers but it does not play and the screen and all of the buttons are off. I would appreciate any more insight you have gained!

Thanks!

 

[Trebor51]

Yes I fixed the problem, it was several of the diodes that had gone in the transformer power circuit. I was able to locate some in the UK and picked them up when I went over in 2018. They are not very dear and really easy to solder in. Cost about$8 to fix. I did not take any photos of the board but if you send me a photo of yours opened up I can point them out to you. Sea.GT.Gruff has posted a link to the service manual which was helpful. After you remove the top lid you can get at the electrics. The faulty diodes were cracked and you need a torch and magnifier to see which ones have gone or test them all. Check out this site. https://www.fluke.com/en-au/learn/b...how-to-test-diodes-using-a-digital-multimeter
Let me know how you get on, the AP-60 is a sweet peace of kit and I didn't want to lose mine so glad I can play it now for years to come.
Rob

 

[Cos]

I have found the diode with your guidance but am struggling to find were to buy a replacement diode can you help ?

 

[Trebor51]

I have found the diode with your guidance but am struggling to find were to buy a replacement diode can you help ?

Did I ever reply to you? I can't seem to find a link. If I didn't, I just want to apologise as I had a heart attack shortly after posting in Oct 2020. I found the diodes online from a company in the UK. I picked them up while I was on holiday over there in 2018. I can't for the life of me remember where it was though. Grey matter going I think.

 

[Vincenzo]

I have a Casio Clavia AP-60R that I purchased secondhand about 8 years ago and it has just gone dead. It has the main power light on and the speakers punch up each time I switch on but no power to the display or other buttons. I have replace a fuse on the main PCB and have tested the transformer and it looks to be working ok although one of the secondary orange wires has a lower voltage. I have with closer inspection now noticed that two diodes connected near the fuse that blew have a crack in them, so I am assuming that they are the cause? They have no ohms reading but I don't know if they are supposed to. I left off the earth from the main PCB to the transformer and switched on only to trip the fuses in my house? I placed the earth lead back onto the transformer and switched on again and all was well but still not working to the display. So the power shortage is going directly to earth when it can without shorting out my house.
I tested some other diodes on the board and they all read about 0.56. Also I have noticed that several of these diodes have red markings by them along with a couple of resistors so I am wondering if this might well have been a problem before and it has already been repaired once before. If anyone has any further information that I can use I would be grateful. I am waiting to obtain some replacement diodes that I found on ebay and when I get around to replacing them I will post to let others know how I went>

I own an AP-60R too.
Piano turns on. but only power led and lcd backlight.
No sound from speakers, no activity on lcd panel, no keys on panel working, all leds on panel always off.
I found a dead IC403 on power board (7805 regulator) that I replaced, also I replaced exhausted capacitors, but same behavior.
I suspect problem is in JCM660-MA1M logic board, but I haven't still locate defective component...

 

[Vincenzo]

I have found the diode with your guidance but am struggling to find were to buy a replacement diode can you help ?

You can easily use common 1N4007 diode, also check IC403, it is a common 7805 (5v regulator), you shoul read with a multimeter a value of 5 volt between pins 2 (-) and 3 (+ output). In my AP-60R radiator on IC403 become very hot: it is normal?