Start with the 4011 I've repaired a LOT of these machines where that's all it needed. Needs to be the "right" kind of 4011 though.
On 1 Jul 2013 17:37, "Nick" <mckenzie126@....uk> wrote:Hi, I wonder if anyone could give me some help with this little drum machine. Play mode seems to work fine & it will start & stop ok & everything sounds ok. Problem is with write mode, the LED stays on & pressing either of the start (S5) or stop (S6) buttons wont advance the sequence & so LED stays on & nothing is written.
I thought id found the problem initially as Q18 was bad but this has been changed now & the problem persists. 4011,C45,C43,C41 have all been replaced & Q15 & Q16 have been checked out of circuit & appear to be working fine. Any hints on what to look for would be great & oh, I have no scope unfortunately.
thanks all
Message
Re: [vintagesynthrepair] Boss DR-55 write mode problem
2013-07-01 by Christian Oncken
two tips..
1) if you drop by your local electronics shop and ask for 4011s make sure they give you 4011s and NOT 4001s. Having to drive 30+ miles to exchange a < $1 part will screw up your whole day.
2) get yourself a logic probe. Cheap and invaluable in this kind of work. I repaired my 606 with the help of a logic probe before I got my scope, picked one up on ebay for like $8. Its much more useful for this type of work than a scope IMHO. Plus, if you're the trusting type and tend to not double check part numbers on chips it can also help you sort out problem 1)... :)
Paul, what's the "right" kind of 4011? The one's they gave me (after they gave me the right ones) worked just fine.. did I just get lucky?
Christian
On Mon, Jul 1, 2013 at 1:10 PM, Paul Rak <paul.rak@...> wrote: