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

Let's Get Technical => All PREAMP Tech Tips & Support => Topic started by: Richie_B on July 31, 2017, 01:42:13 AM

Title: corrosion and grime on pcb... why didn't i notice it before.
Post by: Richie_B on July 31, 2017, 01:42:13 AM
I was taking another look at my mp1 and wondering about the ongoing issue with the chorus. Contemplating just adding an effects unit, maybe a gmajor2. Anyway... I was looking at the right side of the board and noticed how dirty it was. Funny what you see when you change your glasses. Here are a few pics of the mess. I did clean some of it off which you may notice in the second pic. I have to say that to the naked eye, it doesn't look anywhere near as bad as it does in the picture.
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: MikeB on July 31, 2017, 01:48:47 AM
You should try setting a mouse trap.  It certainly looks like something has been living in there.
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: Richie_B on July 31, 2017, 01:58:07 AM
I was thinking the previous owner may have spilled something in there. The other side is pretty much spotless. I've put up a link to a video of the guts of the unit in my dodgy chorus post.
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: Harley Hexxe on July 31, 2017, 01:13:37 PM
  I see some corrosion on a few connections there, I wonder if that might have anything to do with the shakey chorus operation?

   What would be the best thing to use on a PCB to clean it?
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: rnolan on July 31, 2017, 08:52:29 PM
There are some PCB cleaning products, MJMP may be able to recommend a good one.  If there's corrosion on any of the solder joins it's probably worth reflowing them.
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: MarshallJMP on August 01, 2017, 12:07:30 AM
first try to clean it with a small clean paintbrush.
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: Richie_B on August 01, 2017, 02:38:57 AM
I'll go get one tomorrow. Just wondering what sort of paint brush would work best, i was thinking maybe a medium density, not too soft?
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: Richie_B on August 01, 2017, 07:08:04 AM
I was looking up on youtube for clips of cleaning pcbs. I have to say that it made me cringe to see people dropping the board in the sink to clean. I dont think I would use that approach, even if it is the done thing.
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: MarshallJMP on August 01, 2017, 07:55:38 AM
No don't do that, from what I can see it's just some kind of dust, as for the brush something not to hard.
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: Richie_B on August 11, 2017, 04:33:50 AM
Ok, so I brushed away the dust and crud but there have been no changes to the sound. There was another mp1 on ebay recently and it was local. The price was right so i contacted the seller to ask a few questions, got no reply and a few days later it was gone.
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: Richie_B on August 12, 2017, 01:12:44 AM
I took off the bottom panel today. There was dust and a very small spider web. I did also notice some marks on the left that looked like some kind of leak may have happened a long time ago. I've included a picture.
Title: Re: corrosion and grime on pcb... why didn't i notice it before.
Post by: MarshallJMP on August 13, 2017, 09:35:42 AM
Looks quite clean to me, I've seen much worse then this