ADA Depot - A Forum To Support Users of ADA Amplification Gear

ADA Preamps => MP-2 => Topic started by: stevelockridge on February 01, 2015, 09:48:19 AM

Title: Noise and Lights - No Output from MP-2
Post by: stevelockridge on February 01, 2015, 09:48:19 AM
I picked up a used MP-2 last year as a backup to my main MP-2.  The person I bought it from said it was working fine. Well, it's not. When I turn it on, all of the lights for the levels come on and there is a lot of noise.  I am familiar with the noise problem caused by the failed resistor that is mounted under the tubes. I replaced that on my main MP-2 a few years ago. However, I don't remember all of those lights coming on.

http://www.stevelockridge.com/images/ada_mp2/ada-mp2-problem.jpg (http://www.stevelockridge.com/images/ada_mp2/ada-mp2-problem.jpg)

Any ideas what might be causing this and what can be done to fix it?  Thanks.

Steve Lockridge
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ADA MP-2 user since 1993
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Title: Re: Noise and Lights - No Output from MP-2
Post by: MarshallJMP on February 01, 2015, 11:56:54 AM
Are all led's red?If so the CE425 chip is busted.Problem is these were custom made for ADA so there are no replacements.The noise is there because this chip is drawning too much current.Best way to solve this is disconnecting K800 (see attachment),and if this helps removing the CE425.The CE425 is located on the small pcb with all the leds.Now you can also leave the K800 disconnected but tiewrap it to another cable so it doesn't rattle around inside the mp-2.
Title: Re: Noise and Lights - No Output from MP-2
Post by: stevelockridge on March 10, 2015, 01:34:12 PM
I just noticed you had replied to my post.  I assume removing the K800 and CE425 will disable the LEDs.  I will let you know after I try this.

I bought this from a guy who assured me there was nothing wrong with it. It did this the first time I turned it on.  >:(

I would like to find another one that is fully functional if I can.  I looked on EBay but they are very pricey there.  Do you know a place to buy them? (I live in the US.)  Thanks.
Title: Re: Noise and Lights - No Output from MP-2
Post by: MarshallJMP on March 10, 2015, 01:56:51 PM
No problem,keep me updated.
Title: Re: Noise and Lights - No Output from MP-2
Post by: rnolan on March 11, 2015, 06:30:56 AM
Hey Steve, you've got the opposite power problem to me, I need to source 240V MP2s and you need 110v for US.
Hey MJMP, will (I assume removing the K800 and CE425 will disable the LEDs.) this disable the LEDs ? (not that it's a big worry if it all still works...).
MP2s turn up here from time to time in the buy sell ADA gear. Also if you post a want to buy US v MP2 in that area, other members will help if they spot one. Also some of us have gear acquisition syndrome (GAS) real bad (me included), I'm waiting on my 4th (240v) MP2 (insurance  :thumb-up: ). Occasionally, we downsize (well I'm on the uptake right now LOL) and you may pick one up. At least here you shouldn't get shafted. If I spot a 110v model I'll let you know  :thumb-up:
Title: Re: Noise and Lights - No Output from MP-2
Post by: GuitarBuilder on March 11, 2015, 06:34:14 AM
I just noticed you had replied to my post.  I assume removing the K800 and CE425 will disable the LEDs.  I will let you know after I try this.

I bought this from a guy who assured me there was nothing wrong with it. It did this the first time I turned it on.  >:(

I would like to find another one that is fully functional if I can.  I looked on EBay but they are very pricey there.  Do you know a place to buy them? (I live in the US.)  Thanks.

I have an extra MP-2 in great condition that is for sale.  PM me if you're interested.
Title: Re: Noise and Lights - No Output from MP-2
Post by: stevelockridge on March 11, 2015, 07:23:06 PM
Are all led's red?If so the CE425 chip is busted.Problem is these were custom made for ADA so there are no replacements.The noise is there because this chip is drawning too much current.Best way to solve this is disconnecting K800 (see attachment),and if this helps removing the CE425.The CE425 is located on the small pcb with all the leds.Now you can also leave the K800 disconnected but tiewrap it to another cable so it doesn't rattle around inside the mp-2.

MJMP, you are a genius!! K800 disconnected. CE425 removed. PROBLEM SOLVED!! Dumped data from old MP-2 to backup and I am in business. Doing the EPROM update next. Already did it on the old MP-2 several years ago. Thanks for your help.  :bow: :bow:

Steve Lockridge
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ADA MP-2 user since 1993
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Title: Re: Noise and Lights - No Output from MP-2
Post by: rnolan on March 12, 2015, 02:06:42 AM
Hey Steve, good news  :thumb-up: , go MJMP. And GuitarBuilder has a 3rd one for you in good condition  :whoohoo!: , MP2 heaven LOL.
Title: Re: Noise and Lights - No Output from MP-2
Post by: MarshallJMP on March 12, 2015, 08:22:59 AM
Ok Steve no problem,glad i could help out.Now if you have removed the CE425 you can plug K800 back in if you want.