Nord Lead 3 Values Jumping (Arp, Glide, Unison), LCD shows potentiometer values changing randomly

[Angelo K]

Hello friends,
so today I received all the capacitors ordered last week.
After having studied the diagram carefully I intended to replace all the Aluminum electrolytic capacitor SMD ( about 24 years old...) on the LCD Panel board and the electrolytic capacitors on the Power Supply board.
If necessary also some SMD capacitors on the Main Board (on the 5v and 3.3v line - C30, C33, C36, C74, C75).
I only had to replace C3 and C4 as I suggested at the beginning and at the first verification test I no longer have the random value jump.
Now everything is perfect, I am really satisfied.
To unsolder and re-solder I used 2 soldering irons with thin tips and delicate hands (even if there was a bit of shaking, considering the value of the synth!!!).
Intervention of about 10 minutes and the synth is back as good as new!! YESSSSS !!!!

[ghoulian]

Angelo, thats awesome news! I was too scared to replace C3 before hearing if it worked out for you haha. After seeing your post first thing as I woke up, I worked up the courage to go ahead and finally replace C3 as well. Its working! I'm so happy! I nearly ripped a solder pad in the process LOL, but luckily I was able to solder on a new capacitor no problem.

Angelo, thank you so much for your help along the way! It was because of your helpful insight that I was able to get my Nord Lead 3 back up and running again I was beginning to think I was never going to fix it!

[Angelo K]

Hi, I'm glad that the problem has been solved for you too.
For better or for worse, those SMD capacitors all need to be replaced unfortunately, but at least now we know where to start!
I have used the NL3 very little, having other synths too, but seeing it with this problem bothered me quite a bit.
As soon as I was free from other commitments I tried to get my hands on it, and finally after having soldered those 2 capacitors it is now perfect.
For anything, at your disposal!
Greetings from Italy!

[ghoulian]

Hi all, unfortunately the issue has returned and it's become even worse. Everything was working great after replacing the two capacitors mentioned in this thread, but suddenly after having left the Nord Lead 3 on for a few hours the Arp, Glide, and Unison potentiometers dont register anything when moved. I also noticed a few times that it would show me the values changing randomly again although its not as frequent.

This is such a bummer as I was convinced this keyboard was fixed. Just wanted to make an update on this. Im feeling a bit lost and unsure of how to move forward.

EDIT: The morning after, things seem to be fine again? The pots are now working. Maybe I will have to contact someone to get the power supply rebuilt. If anyone knows of someone that repairs Nord power supplies please let me know! Im wondering if it got too hot during operation.

[Angelo K]

Hi,
I'd say check the solder joints you placed on the capacitors carefully; they might not be perfect and have a slight leakage.
I still think you need to replace all the electrolytic capacitors on the boards, both the LCD board, the main board, and the power supply.
In fact, I bought all the spares and will replace them as soon as I can.
You could try another test, since everyone has complained about power problems with the Nord Lead 3:
plug the power outlet under a UPS and not directly into the wall outlet, so you get cleaner power without any interference or voltage drops.
Also, there was a modification that needed to be made, which was to add a capacitor to a pin on the power board. If I find the post from about 10 or maybe 15 years ago, I'll post the link here.
From what little I've been able to test, I don't seem to see any significant changes in the potentiometers, and I remain convinced that it depends on the electrolytic capacitors used in this project, which lose their capacity after about 20 years.
I'll update you in the next few days; I'll do more tests...
The only negative thing is that I've noticed that the aftertouch is causing problems. Perhaps the connector isn't making good contact, and unfortunately there are no spare parts. The entire Fatar TP9S keyboard needs to be replaced.

[Mr. Marko]

this is a fantastic thread...thank you folks!