abnormal signal in channel 2

[Reinhard]

Hi, Everyone,

Did you ever meet the problem that some channels are not working? In my situation, the channel 2 is strange. When the power is on, the noise of the channel 2 can be reduced. When I input sine signal from functional generator, the channel 2 shows nothing. However, the problem will disappear sometimes. I checked the connection of the cables, nothing found. Is there anything I can try to solve the problem?

[Jon Newman]

This is very common and is likely due to a poor contact between the amplifier's gold pin and the MEA contact pad. Two things to try:

1. Clean the MEA contact pads using a small amount of isopropyl alcohol with a cotton swab. 

2. When the MEA is in the amplifier, gently nudge the contact pad laterally (not up and down) using the wooden end of the cotton swab.

On Sat, Mar 21, 2015 at 11:28 PM, Reinhard <laos...@gmail.com> wrote:

Hi, Everyone,

Did you ever meet the problem that some channels are not working? In my situation, the channel 2 is strange. When the power is on, the noise of the channel 2 can be reduced. When I input sine signal from functional generator, the channel 2 shows nothing. However, the problem will disappear sometimes. I checked the connection of the cables, nothing found. Is there anything I can try to solve the problem?

--
You received this message because you are subscribed to the Google Groups "NeuroRighter Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to neurorighter-us...@googlegroups.com.
To post to this group, send email to neurorigh...@googlegroups.com.
Visit this group at http://groups.google.com/group/neurorighter-users.
For more options, visit https://groups.google.com/d/optout.

[Reinhard]

Thank you, Jon. I cleaned the pad and pins, it is better now. However, some certain channels will still be abnormal sometimes even I changed the MEA, I think it's caused by the pins of the amplifier.

On Monday, March 23, 2015 at 12:18:59 AM UTC+8, Jon Newman wrote:

This is very common and is likely due to a poor contact between the amplifier's gold pin and the MEA contact pad. Two things to try:

1. Clean the MEA contact pads using a small amount of isopropyl alcohol with a cotton swab. 

2. When the MEA is in the amplifier, gently nudge the contact pad laterally (not up and down) using the wooden end of the cotton swab.

On Sat, Mar 21, 2015 at 11:28 PM, Reinhard <laos...@gmail.com> wrote:

Hi, Everyone,

Did you ever meet the problem that some channels are not working? In my situation, the channel 2 is strange. When the power is on, the noise of the channel 2 can be reduced. When I input sine signal from functional generator, the channel 2 shows nothing. However, the problem will disappear sometimes. I checked the connection of the cables, nothing found. Is there anything I can try to solve the problem?

--
You received this message because you are subscribed to the Google Groups "NeuroRighter Users" group.

To unsubscribe from this group and stop receiving emails from it, send an email to neurorighter-users+unsub...@googlegroups.com.

[Jon Newman]

Maybe so. Are you storing your amplifier in an incubator? If so, it must not be at 100% relative humidity or you can start to see electrical anomalies like this. The incubator should be kept down around 65% relative humidity. Additionally, it could be caused at the interface between the amplified signal and the NI breakout boards. 

[Jon Erickson]

I've also experienced something similar - changing MEAs and getting
all signals to look good required carefully applying pressure to push
the top plate down and then sliding over the white plastic locking
tabs, then slowly letting up on the top plate so that spring-loaded
contacts are still good. Sometimes it took a few tries, but always
worked in the end with careful adjustment. Be sure to have NR showing
traces as you are doing this.

>>>> an email to neurorighter-us...@googlegroups.com.

>>>> To post to this group, send email to neurorigh...@googlegroups.com.
>>>> Visit this group at http://groups.google.com/group/neurorighter-users.
>>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>>
>

> --
> You received this message because you are subscribed to the Google Groups
> "NeuroRighter Users" group.
> To unsubscribe from this group and stop receiving emails from it, send an

> email to neurorighter-us...@googlegroups.com.

[Reinhard]

Hi, Jon,

Yes, my amplifier is in an incubator, but the humidity should be low since no water inside. Because my MEA has a PDMS lid and after testing I will return it to another incubator, I didn't put any water into the testing incubator.

On Friday, March 27, 2015 at 10:04:19 PM UTC+8, Jon Newman wrote:

Maybe so. Are you storing your amplifier in an incubator? If so, it must not be at 100% relative humidity or you can start to see electrical anomalies like this. The incubator should be kept down around 65% relative humidity. Additionally, it could be caused at the interface between the amplified signal and the NI breakout boards. 

On Fri, Mar 27, 2015 at 4:50 AM, Reinhard <laos...@gmail.com> wrote:

Thank you, Jon. I cleaned the pad and pins, it is better now. However, some certain channels will still be abnormal sometimes even I changed the MEA, I think it's caused by the pins of the amplifier.

On Monday, March 23, 2015 at 12:18:59 AM UTC+8, Jon Newman wrote:

This is very common and is likely due to a poor contact between the amplifier's gold pin and the MEA contact pad. Two things to try:

1. Clean the MEA contact pads using a small amount of isopropyl alcohol with a cotton swab. 

2. When the MEA is in the amplifier, gently nudge the contact pad laterally (not up and down) using the wooden end of the cotton swab.

On Sat, Mar 21, 2015 at 11:28 PM, Reinhard <laos...@gmail.com> wrote:

Hi, Everyone,

Did you ever meet the problem that some channels are not working? In my situation, the channel 2 is strange. When the power is on, the noise of the channel 2 can be reduced. When I input sine signal from functional generator, the channel 2 shows nothing. However, the problem will disappear sometimes. I checked the connection of the cables, nothing found. Is there anything I can try to solve the problem?

--
You received this message because you are subscribed to the Google Groups "NeuroRighter Users" group.

To unsubscribe from this group and stop receiving emails from it, send an email to neurorighter-users+unsubscribe@googlegroups.com.

[Reinhard]

Thank you, Jon, I will do it carefully.

>>>> an email to neurorighter-users+unsub...@googlegroups.com.

>>>> To post to this group, send email to neurorigh...@googlegroups.com.
>>>> Visit this group at http://groups.google.com/group/neurorighter-users.
>>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>>
>
> --
> You received this message because you are subscribed to the Google Groups
> "NeuroRighter Users" group.
> To unsubscribe from this group and stop receiving emails from it, send an

> email to neurorighter-users+unsub...@googlegroups.com.

[Jon Newman]

I'm not sure I fully understand what you are saying, but just i case I'm misinterpreting: The PDMS lid is not going to protect you amplifier at all. The amplifier should never be stored at high humidity levels.

To unsubscribe from this group and stop receiving emails from it, send an email to neurorighter-us...@googlegroups.com.

[Reinhard]

Sorry for the misunderstanding. I meant there's no water in the reservoir of the incubator. So the humidity in the incubator is about 20%.

To unsubscribe from this group and stop receiving emails from it, send an email to neurorighter-users+unsub...@googlegroups.com.