@hifiamps
Hi, Just wanted to give you an update on what did: I unplugged both connectors from P101 and P102. Only thing connected is the mains using the earth ground to chassis, the speaker outputs L/R, and the wires going to the RCA connectors from the board. Turned it on and then same issue with switching ON-Standby. So I connected the amp to my Variac and started lowering the voltage a little at a time. I had to turn it down to 92V before it finally stopped this erratic switching. Been playing now and had no issues. Hmmm, now what should I do? Perhaps it could be that a smd resistor has been fried? Let me know your thoughts, and thanks again for the info!
Hi, Just wanted to give you an update on what did: I unplugged both connectors from P101 and P102. Only thing connected is the mains using the earth ground to chassis, the speaker outputs L/R, and the wires going to the RCA connectors from the board. Turned it on and then same issue with switching ON-Standby. So I connected the amp to my Variac and started lowering the voltage a little at a time. I had to turn it down to 92V before it finally stopped this erratic switching. Been playing now and had no issues. Hmmm, now what should I do? Perhaps it could be that a smd resistor has been fried? Let me know your thoughts, and thanks again for the info!
I think that confirms a problem with your module.
Standby is internally pulled low when not connected (standby is off without a connection to P101).
You could try connecting a jumper from Ground pin 4 to pin 6 standby on P101. Maybe the internal ground connection is broken.
You could also try to pull the trigger pin high (5V, but apparently it can tolerate up to 12V input). See page 32.
11.5.7 Trigger Input
When the 1200AS is in standby-mode set by a high on the Standby input, the module can be powered up by a high on the Trigger input (pin 18 on P102). If this circuit still works, this would be a way to get the amp running.
I have only read a couple of posts on the problem, and some people report hearing a relay switching when it goes into standby mode. Maybe it's a bad relay or the circuit driving the relay.
When you have the amp running on 92V, can you read the voltage at pin 17 P102 (standby indicator, active low). Or reconnect P102 and see if the standby LED is lighted. The amp may still be in standby mode, but it doesn't have the energy to switch the relay?
Standby is internally pulled low when not connected (standby is off without a connection to P101).
You could try connecting a jumper from Ground pin 4 to pin 6 standby on P101. Maybe the internal ground connection is broken.
You could also try to pull the trigger pin high (5V, but apparently it can tolerate up to 12V input). See page 32.
11.5.7 Trigger Input
When the 1200AS is in standby-mode set by a high on the Standby input, the module can be powered up by a high on the Trigger input (pin 18 on P102). If this circuit still works, this would be a way to get the amp running.
I have only read a couple of posts on the problem, and some people report hearing a relay switching when it goes into standby mode. Maybe it's a bad relay or the circuit driving the relay.
When you have the amp running on 92V, can you read the voltage at pin 17 P102 (standby indicator, active low). Or reconnect P102 and see if the standby LED is lighted. The amp may still be in standby mode, but it doesn't have the energy to switch the relay?
Last edited:
If there is a relay, that could be good thing. They can be replaced. If relay replacement doesn't solve the problem, then remove the relay and solder jumper wires so the amp is in an always ON state.
I like things simple. Just AC power ON/OFF, signal input, speaker output. That's all you really need in an amp.
I like things simple. Just AC power ON/OFF, signal input, speaker output. That's all you really need in an amp.
They would look like this. I don't see one looking at pictures of the PCB. The click is fairly loud and distinctive. They often have a small schematic with coil and the switching elements, like the ones in the link. You could easily clip one of the leads to the coil disabling it. Does the relay click when the amp is first powered on or only when going into standby?
Relay
Relay
Last edited:
It makes the same noise when first powering up the amp. I have another photo I can post that shows more.
I guess the only thing I can do is to disconnect everything and take it out of the chassis and try and get more photos? I mean at this point, I can't really go wrong..lol
So where is that clicking sound coming from when the amp is turned on? I imagine the issue lies somewhere close by? I am guessing it's possible it could be a smd resistor?
Just look for any identifying marks because it's either a relay or a capacitor. The other large ICE modules I have all use mechanical relays as part of the standby circuit, but I've never held a 1200AS2.
If your indicator LEDs show that it is going from blue (ON) to amber (standby), then the relay and relay control is working. The logic is not correct. The first thing I would try to do is connect a jumper from ground to P101 pin 6 with both P101 and P102 disconnected. If that doesn't work, then I would try the trigger input P102 pin 18 (5-12V). The trigger should force standby off. You can get a jumper by removing unused wires from the JST housing and using shrink wrap tubing (the unused wires should be removed anyway).
Jumpers
Jumpers
Last edited:
I think you were on the right track with the idea of disconnecting everything and taking lots of pictures. At the very least, your wiring inside the chassis should be cleaned up. Use proper crimp connectors or terminal strips. Wire nuts are always suspect. Plus that big loom of wires should be shortened and addressed. Poor or stray contacts could cause these modules to misbehave.
@hifiamps
On P101 connector I originally had pins 3 and 6 connected together. That is the only jumper I did on that P101 connector. For P102, I connected pin# 17 to the anode side of the amber colored LED for standby mode, then connected pin#15 to the anode side of the blue LED for power ON. Both LEDs cathode sides where connected together to pin#13. For the RCA connections, I used pin#21 to connect to the hot side of right channel RCA, then connected pins #20 & #22 that go to the cold side/ground of the right channel RCA.
So do you still think I should unplug all connectors from P101 & P102, but just connect pin#6 (P101) to ground? Are we talking about the earth ground I have that attaches to chassis?
On P101 connector I originally had pins 3 and 6 connected together. That is the only jumper I did on that P101 connector. For P102, I connected pin# 17 to the anode side of the amber colored LED for standby mode, then connected pin#15 to the anode side of the blue LED for power ON. Both LEDs cathode sides where connected together to pin#13. For the RCA connections, I used pin#21 to connect to the hot side of right channel RCA, then connected pins #20 & #22 that go to the cold side/ground of the right channel RCA.
So do you still think I should unplug all connectors from P101 & P102, but just connect pin#6 (P101) to ground? Are we talking about the earth ground I have that attaches to chassis?
@von Ah
Hello Von, Thanks for your input! Yes I know I need to clean the wiring up..lol I will do that as soon as I find out what's causing my issues. I tried taking a photo of what may be this relay switch. Not sure if it is or not. Can't find any schematics for the 1200as2 module I have 🙁 Also so many tiny smd's on the board as well..lol Perhaps I can get some direction or help trouble-shooting my issue. I know a very little bit about basic electronic stuff, but I'm sure you guys know more. Anyhow, here is another photo I took which may be this relay? I'm just thinking that if this is the relay, then either it is working properly, or about to fail completely. I can see a partial part number on this could be a relay..lol It is showing 80210/OWTC? Not sure though!
Hello Von, Thanks for your input! Yes I know I need to clean the wiring up..lol I will do that as soon as I find out what's causing my issues. I tried taking a photo of what may be this relay switch. Not sure if it is or not. Can't find any schematics for the 1200as2 module I have 🙁 Also so many tiny smd's on the board as well..lol Perhaps I can get some direction or help trouble-shooting my issue. I know a very little bit about basic electronic stuff, but I'm sure you guys know more. Anyhow, here is another photo I took which may be this relay? I'm just thinking that if this is the relay, then either it is working properly, or about to fail completely. I can see a partial part number on this could be a relay..lol It is showing 80210/OWTC? Not sure though!
