Casio AP65-R problems

[Dani]

Hi, everyone, this is my first post of (hopfefully) many on these forums, so hello!!

I have recently been given an AP65-R that was simply described as "not working". After a bit of poking around inside, I can see all the fuses work, and found a service manual on the internet and have managed to identify the various components, and have not found any blown capacitors etc.

My problem is this: I can turn it on, and the power indicator turns on, and the main LCD fires up and seems all good, but the keyboard doesn't seem to be detecting any keypresses, and every now and again I hear a little POP, and the keyboard immediately turns itself off and on. Rinse repeat. I also detected a funny smell, but that might just be because it hasn't been turned on in a long time.

Does anyone think they might be able to shed a little light on this? Will I need to buy a new main PCB, and if so does anybody know of a second hand parts dealer I could get one from?

Thanks very much for reading

 

[happyrat1]

First of all what's the mechanical condition of the keybed? Does anything rattle inside? Possibly a stuck switch or key or a shorted out screw that's messing up the POST on bootup?

Check all the switches to see if anything's stuck in ON position.

Gary

 

[Dani]

Hi Gary! Thanks for your response

Unfortunately I don't think that is the case, the keybed seems fine, and the keyboard seems to be posting ok. Plus, a new problem seems to have manifested itself since last night; it turns on (though still not responding to keyboard presses), and usually before I get the chance to try any troubleshooting, the LCD goes blank and a disturbing buzz comes from the speakers until I turn the power off again. I'm starting to think it's the main board

Do you perhaps know where I might be able to salvage one? Are they standardised in any way? I'd really love to get this little beast working, I want to hear her sing!

 

[happyrat1]

I'm thinking your only hope for parts might be picking up a junker on ebay but it may suffer the same problem as the one you have.

At any rate, Casio no longer supplies parts for it.

Sorry I can't be more helpful. This is a puzzler.

Gary

 

[Dani]

Hi there,

Just thought I'd update this thread for anyone else who might be having problems with their AP65. After much jiggery pokery, I discovered the problem was definitely the mainboard, which is a pain seeing as they are discontinued. However I have found an electronic instrument repair shop in Essex, UK (I live in the British Isles) called WD Greenhill, who immediately knew my problem from me mentioning the model number (a common fault apparently), and said that they could fix it for me, and at a very low price too! So I think I might be sorted!!

Hopefully this info will be useful for anyone else who has had the same problem, it won't cost you an arm and a leg to get yourself up and running again

 

[prof]

Hi Dani,

I have exactly the same problem with my AP65R. But I live not in Essex, UK , I live in Germany. Could you give me a service manual link and any information about this fault?

Thanks very much

 

[prof]

My first question was done by elektrotanya com

 

[Dani]

Hi Dani,

I have exactly the same problem with my AP65R. But I live not in Essex, UK , I live in Germany. Could you give me a service manual link and any information about this fault?

Thanks very much

Sorry, I'm not able to help you at all, as I ended up just throwing the damned thing out and buying a piano.

Also got to really post a review of my experience with WD Greenhill. They were absolutely shocking. I was constantly fobbed off with nonsense stories about them ordering parts that would be there by X date, only for me to ring up weeks after it should be finished to be given a further nonsense excuse about the same part being ordered "right now". This happened several times over the course of almost six months. it was a hugely disappointing experience, and when they sent the board back the keyboard STILL wouldn't work - it would switch on but go back off again as soon as it warmed up. I did some poking around with a meter to find the chip that was broke, and found it was a broken voltage regulator, however by this point i was so disillusioned with the experience i decided to call it a day. Don't know why they didn't think to test the thing before they sent it back, especially since the 'service' cost me 128 quid plus 6 months of feeling like a stalker ex boyfriend' constantly ringing them to light a fire under their arses. Solid 1 out of 5 stars for WDGH, would not use again.

 

[Music Repair Depot]

Hello Forum,

We have one of these units AP-65R in our shop right now. We are a Casio service center. I have a similar problem with this unit as mentioned here. Boots up fine, shows Grand Piano on the display, unit appears "locked up" none of the buttons respond, no LED's come on, no sound and no response from the keyboard. I did replace the 5 volt regulator in the power supply as the display was dead. Anyone have any ideas what might be going on with the Main board, Casio doesn't have any parts listed for it. Older couple owns it and really would like it fixed. I generally don't attempt to repair main CPU boards for Casio units because its just easier and less expensive to replace it when you consider the troubleshooting time and labor, its just not worth it.

 

[happyrat1]

If you want to narrow it down to a specific chip then as a Casio Service Center you have access to full schematics I presume.

Systematic troubleshooting would indicate going in there with a logic probe and a logic pulser and checking each chip for clock signals and transitioning logic states when switches are activated and / or signals are injected.

You seriously should have access to everything you need for a board level repair, but there really are no shortcuts for this sort of troubleshooting.;

Gary

 

[Music Repair Depot]

Yes Gary, I have the schematics and service manual, and yes, I can do component level. HOWEVER... my 35 years of wisdom and experience tells me that the unit and main board are not worth the time in labor of this kind of in depth troubleshooting. I have checked the basic stuff, regulators, clock, strobe, reset lines etc and to no avail of common stuff. Of course there is that possibility I have overlooked something. In my years of component level repairs on main boards there is usually a common failure that becomes known and a tech proceeds accordingly to repair the board. I'm fairly sure this is not an obscure problem. I usually rely on tech notes from the manufacture when available as it save much time, in this case the unit is no longer supported by Casio.

 

[happyrat1]

In that case my advice is for the elderly couple to sell it off on ebay or craigslist as nonfunctioning for parts only and spend $500 or so on a new Privia or find a decent deal on a used Casio on the same boards.

I realize they may be a charity case but all I can advise is to walk away from it and help them find an economical replacement out of the goodness of your heart.

Gary

 

[Music Repair Depot]

Yes, pretty much. I just don't like stuff leaving the shop unrepaired. They are out a playing digital piano and a bench deposit.

 

[happyrat1]

You could always be a good guy and eat the deposit. How much time you wasted on diagnosis is your business, but it's really nobody's fault that it's unfixable.

Or at the very least cut them a 50% seniors's discount on the deposit.

It's tough enough to make it on what passes for a pension cheque these days without throwing good money after bad.

Gary

 

[prof]

I have invested for my Casio AP-65 a lot of time and found out that the 5 volt regulator is OK and the main board is faulty. The voltage regulator was shorted by main board. The main board has 3 ohms resistance between VDD and GND. I asked Casio Service for the main board. The main board is unfortunately not more deliverable. The game is over. I can try to sell my Casio at ebay and buy new keyboard.

 

[Music Repair Depot]

I have invested for my Casio AP-65 a lot of time and found out that the 5 volt regulator is OK and the main board is faulty. The voltage regulator was shorted by main board. The main board has 3 ohms resistance between VDD and GND. I asked Casio Service for the main board. The main board is unfortunately not more deliverable. The game is over. I can try to sell my Casio at ebay and buy new keyboard.

Yes, exactly the same as you described is what I found. I initially thought it was a bad 7805, so I replaced it and then further troubleshooting determined a short somewhere else. Nigel Greenhill had stated in an email that they successfully repaired many of these when parts were available, and that part is the main processor that goes in these, kinda rare, but I suspected something was up as it did appear as not much activity when probed with the scope. So, I will see if I can get a used board for a salvage unit.