Hi there. I have an issue I can't figure out. If someone could offer any advice on this that would be great.
The device is a Yamaha D1500 digital delay. The service manual is attached in the next post, but no good schematics are there. I attached a diagram of the LED meter from a SPX90 that looks to be set up the same way, and uses the same driver IC (IR2E19).
The problem is some of the LEDs in the LED meter stack are not lighting properly. At this point only the top three will light with the higher audio input levels. The lower LEDs on the meter stack will not light. The two on the very bottom used to light until I did some attempts to get the middle ones to light by shorting some connections, hoping for power to them.
Anyway, I replaced the LED driver IC (a supposed substitute I could find for the IR2E19), but there was no change. I have gotten some of the other LEDs in the stack to light by accessing some voltage source, but nothing consistent, so I do not know that the LED stack itself is defective. I also tried another LED stack which didn't work at all, but then I do not know the voltage requirements for that.
The D1500 works fine other than this audio meter issue. Could there be an issue with a capacitor or something that drives the IC? I wish the schematic showed acceptable voltages for the inputs, otherwise I do not know what are good or bad voltages.
Also, it would be helpful to understand why some LED's are in series. I cannot find a datasheet for the IR2E19.
Thanks!
Clay
The device is a Yamaha D1500 digital delay. The service manual is attached in the next post, but no good schematics are there. I attached a diagram of the LED meter from a SPX90 that looks to be set up the same way, and uses the same driver IC (IR2E19).
The problem is some of the LEDs in the LED meter stack are not lighting properly. At this point only the top three will light with the higher audio input levels. The lower LEDs on the meter stack will not light. The two on the very bottom used to light until I did some attempts to get the middle ones to light by shorting some connections, hoping for power to them.
Anyway, I replaced the LED driver IC (a supposed substitute I could find for the IR2E19), but there was no change. I have gotten some of the other LEDs in the stack to light by accessing some voltage source, but nothing consistent, so I do not know that the LED stack itself is defective. I also tried another LED stack which didn't work at all, but then I do not know the voltage requirements for that.
The D1500 works fine other than this audio meter issue. Could there be an issue with a capacitor or something that drives the IC? I wish the schematic showed acceptable voltages for the inputs, otherwise I do not know what are good or bad voltages.
Also, it would be helpful to understand why some LED's are in series. I cannot find a datasheet for the IR2E19.
Thanks!
Clay