I\u2019m a bit puzzled and no one else seems to have picked up on this, solder cannot rust it has no iron in it! So just what do you mean by the solder has rust on it? Note also that the PCB tracks are made of copper and they are either tin plated of solder plated or varnished so again they do not contain iron ergo they also cannot rust.
From:
vintagesynthrepair@yahoogroups.com [mailto:vintagesynthrepair@yahoogroups.com] On Behalf Of Antoine Deschênes
Sent: Thursday, 26 January 2006
19:51
To:
vintagesynthrepair@yahoogroups.com
Subject: Re: [vintagesynthrepair]
Roland RD-300S trouble
Well I'm sure that the
problem is on the PCB because there is some rust
on the diode solder points that connect to the 7
notes with
problems.(They are all one next to the other)
Does it matter if I use an other kind of diodes?
grantbt@... a écrit :
> I don't know this unit, but I think they are
probably
> just common signal diodes like 1n4148 or
1n914.
> If it's not the wiring/solder/diodes, it
could be the
> chip that is either driving the keyboard scan
lines
> or the chip that is reading them.
You'll have to
> follow the traces to find the offender...
>
> -----Original Message-----
> >From: Antoine Deschênes
> >Sent: Jan 26, 2006 7:20 AM
> >To: vintagesynthrepair@yahoogroups.com
> >Subject: [vintagesynthrepair] Roland
RD-300S trouble
> >
> >Hi,
> >
> >Someone asked me to fix a Roland
RD-300S(7 notes not working). I managed
> >to open it and remove the keys. Now, the
only problem is that there is
> >some rust on the solders, but the contact
looks OK(After cleanup). I'll
> >re-work the solder points tomorrow, but
I'd like to know the diode type
> >in case that one of them is dead.
> >
> >--
> >Antoine