Roland XP50 LCD Display Problems

Can someone verify that this list is correct?

14 x 10uF 16V
05 x 47uF 6V
03 x 100uF 6V
02 x 330uF 6v
02 x 0.1uF 50V
01 x 4.7uF 50V

I would like to order the new capacitors before I take the xp-50 apart...

Can anyone tell me if I am reconnecting my ribbon cables correctly? The colored wire on the black cables are considered PIN 1 right?

Looks good to me! Thats the same list I used!

I've just taken the XP-50 apart and desoldered all the smd caps. Just a question about the values.

The numbers on a cap will say for instance:

51
10
16V

Does that mean 10uF 16V?

And

52
330
6V

is 330uF 6V? If so what does 51 and 52 mean?

my guess is: It is the lot number or the model number.

Right. I have replaced all caps, put the whole thing back together and I still have exactly the same problem :')

The xp50 powers up just fine but it only produces a loud pulsating static noise. It said "user memory damaged" so I replaced the cr2032 and did a factory reset. I can now hear the sounds but only faintly and there is still the loud static noise which you hear continiously even with no keys pressed. Any ideas?

Some of the old caps had leaked but the main board looks fine. I cleaned it thoroughly after I removed the old caps.

The pulsating noise has a +- 2 seconds wave and sounds digital.

Done some more testing. In test mode cpu and ram all OK. Sound test sends a sinus wave to left output and a square wave to the right output. I can hear both under a thick layer of static. Line out and phones out are both distorted. I measured the voltages from the psu board to several components and what should be 5v is exactly 5v and 15v is 15.2v and -15v is -15.4v.

So: I started with an xp50 with distorted sound, replaced all 27 caps and nothing changed :-) help!

*switches on batman/cesarsound sign*

Valentine,
I don't know if you did it, but try to clean (or wash) the mainboard with isopropyl alcohol and a brush.
The leaked caps may leave some acids on PCB and this acid is conductive and can cause such problems.

Good luck.
Cesarsound.

Hi Cesarsound,

I've clean the pcb where the caps sit after I removed the old caps (and solder with desoldering wire) with q-tips and cleaning alcohol. There wasn't much leaked electrolite on the pcb at all.. I can show you some pictures but the pcb looked very clean after I removed all the old stuff. The problem could also be inside the pcb I think because it sat in a closet for a few years while it was broken the previous owner told me.

Here's a link to my blog where you can see the pictures:

https://synthsandkeyboards.wordpress.com/2015/05/06/roland-xp-50-music-workstation/#more-191

There where a few pads that hold the caps that were pretty corroded (921 and 922 for example, see pics)

Is it possible to tell by the schematics which part of the pcb could be the problem?

Thanx!

I'll remove the pcb and clean the entire thing with cleaning alcohol somehow.

Hi Valentine, now I could see your blog, very good repair informarion there!

Tnx :-)

I have taken the main board from the xp50 again and inspected it in daylight. I must say there was still a lot of residue from the leaked caps on the board connecting a lot of new caps. I this stuff conducts electricity I can imagine there will be trouble :-) I removed half of the new caps and thoroughly removed all residue.

Three problems:

I have managed to rip off the negative pad for c175. I have the schematic but I have trouble assessing where it leads..

There seems to be a spot where a smd resistor used to be.. only to slightly burned spots left. It's r82 Which is very close to the cr2032 battery. Which value should r82 have?

On the backside of the pcb another spot where it looks like an smd resistor used to be.. r940 although I'm not sure there used to be a resistor in that spot looking at the photo's right now. Looks pretty clean.

Will upload photo's soon.

Hi Valentine,

Where did you buy the SMD electrolytic capacitors? Now I will have to replace all caps on my XP50.

Thanks,
Cesarsound

I bought regular caps. Not smd.

I have received the SMD Caps. Now hands to work.