Need advice fixing Boss Dr.55 drum machine

[nathanscribe]

Good news, mr. method! Glad to hear you're back up and running.

Cheers for the offer, but I have loads of ICs kicking about, and probably a few dozen 4011s. I haven't been back into the DR for a while, too busy.

Anyway, yes, that's a good point about dealer websites providing links to datasheets, and they're always worth downloading and filing away.

[joe6167]

Hi All,

I've had similar problems with my DR-55, ie you could program patterns into the machine, but it would not play them back. Well, I picked some CD4011UBE Chips from Digikey (www.digikey.com they are only $.50 a peice plus shipping, and no minimum charges from these guys) I had removed the old '4011 and put the new one in and it now works just fine.

As an added bonus, with the old chip, I found that the hi-hat wouldn't work when set to "8" only when set to "12+16". With the new chip, it works as it should.

Cheers,

Joe

[electroluver]

Boss DR-55

I've got a very similar problem described in the previous posts. When I turn on the DR-55, I'm able to hear the sounds in write mode, but when I switch over to write mode and press play, it sticks. I'm pretty sure it's the CD4011UBE chip and I would like to find a replacement. If anyone has an extra, please e-mail me at blun8@yahoo.ca and I'll pay for it.

[joe6167]

Check out digikey.

[Enzo]

4011 is a common CMOS logic IC.

[Tobynbritt]

My dr 55 is fried

I was a bonehead and plugged a 12v adapter into my dr 55 and It seems to be done for. The led blinks a bit when I turn it on but that's all I can get out of it. Would I have any luck replacing the IC's or is this thing shot? I'm fairly new to electronics and the 55's PCB is kinda overwhelming for me. Not really sure how to start and I really don't want to buy a new one. Love this little guy.

Thanks!

[methodofcontrol]

the light comes on. so your protection diode didn't do it's job. (they're supposed to fail if you hook up wrong power)
but, it's likely you need the 4011 chip. i can help you with that if you're not sure. PM me for details.

[Enzo]

Why not put those details right here in the forum, for everyone to see and benfit from?

[electroluver]

Boss DR-55

Right, so I decided to just trade the Dr55 instead of fixing it. I know the 4011 is a common CMOS logic IC, yet a good deal made the choice obvious.

[Tobynbritt]

So the light doesn't actually come on, it just flashes when I turn it on and off. Should I go ahead and order the 4011 chip? Does that diode need to be replaced?

Thanks!

[methodofcontrol]

those chips are cheap. when i fried my dr55, it was similar circumstances. and that chip solved my woes.
does yours still make noise? it may not sequence, but if hooked up to a speaker/amp/headphone...does it still make any sound?

[Tobynbritt]

No sounds come out at all. Is there a best web site for ordering IC's? I found a lot of 4011 chips out there but they have different letters before and after the number. Are all 4011 chips the same?
I entered the part # at Jameco and they gave me this

74C00: MAJOR BRANDS: ICs & Semiconductors

Will this little guy work? The CD4011 is there too but I don't have a clue what the difference is.

Thanks so much for the help!!!

[Enzo]

Well, one difference is that the CD4011 is what the circuit wants while the 74C00 is the 74C series equivalent. That may or may not cause a problem depending upon the circuit. Some CMOS logic ICs are even used in audio signal paths. In this case, the difference probably does not matter

ANother difference is that that 74C00 is selling there for an amazingly high $2.19 each, while the 4011 sells for a more reasonable 25 cents.

The letters before 4011 mostly identify the maker the texas Instrument ones start with CD, while the Motorola (On Semi)ones start with MC1, for example. The letters after 4011 refer mainly to the package - the physical shape - and sometimes how it is shippped.

As long as it is a quad NAND gate, any 4011 should work. As to the package, the ones that look like your 74C00 example are what we call a "DIP" package. (Dual Inline Package) It has two rows of legs that fit through the holes on your circuit board. Most you will see are plastic, but they also come or came in ceramic. That won;t matter, pick one. And some have extended temperature range. Chances are you will not be playing the thing at temperatures below freezing or above the temperature of your coffee, so ignore that. And we are still transitioning into the green era, so some old stock is still around with tinned legs, and newer stock will be "lead-free" or "green" or whatever. None of that affects how it works in your unit. If the environment is impoprtant to you, go ahead and get the green versions.

We are all assuming this is what your unit needs.

[methodofcontrol]

i have an extra 4011 from when i ordered a few years back. i can send you mine if it helps you. $5 shipped should cover it. i don't have it right next to me, but if you'd prefer i could get the letter codes off it for you later.

[Tobynbritt]

Seriously, thanks for all ya'llz help!!!

I just ordered a few 4011 chips. Thanks m.o.c. but I wanted to get a few of them. Gonna put em on the breadboard and see what I can do.
Going to replace the dr55's 4011 and also install a socket to avoid more tiny soldering jobs if the chip for whatever reason doesn't work. I'll get back with my results!

Also, out of curiosity does anyone remember having a sticker with a number on the top side of the pcb right above the 4520 IC? mine says 001 and I'm just wondering if maybe it was the first one out or something? Would be pretty cool if it was.

Cheers!