Roland Electronic Drums
 

I got two of these, one is a TD-7 and one is a TD-8. They seem to respond to input but do not make sound. The little "trigger" light lights up.

I also have one of another brand that only puts out sound through the headphone jack.

I am comoing up with a blank finding prints fro these. Anyone know any common failure oes or whatever, or worked on a bunch of them ? Need a couple of tips.

Roland Electronic Drums
 

wrote:
I got two of these, one is a TD-7 and one is a TD-8. They seem to
respond to input but do not make sound. The little "trigger" light
lights up.

Something you may have already checked:

A lot of stuff that makes noise and has MIDI outputs has different
operating modes:

1. When you play it, make noise and send the related MIDI message
2. When you play it, make noise only, no MIDI
3. When you play it, no noise, only send the related MIDI message

PDF page 15 (paper page 13) of
http://media.rolandus.com/manuals/TD-7_OM.pdf
suggests that the TD-7, at least, can do #3. That page has the setting
for #3, and the default setting that makes it do #1.

There is a "master reset" (PDF page 135, paper page 133) that should
put everything back to defaults, but if the customer has customized some
of the patches (sounds) or other settings, those will be lost.

In general, with stuff from this era, you fight the fact that it has a
very wide range of settings, coupled with a tiny character LCD and a
couple of buttons as the user interface. You *can* get to and change
all of the settings from that interface... it just takes a while.

Matt Roberds

Roland Electronic Drums
 

wrote:
I am comoing up with a blank finding prints fro these.

Also, the first hit on http://lmgtfy.com/?q=roland+td-7+service+manual
is http://www.synthmanuals.com/manuals/...ervice_manual/ ,
which coughs up a PDF.

That site (and some others I tried) don't have a TD-8 manual. There
are a couple of sites that want to sell you the manual, but they could
be the ones that just sell you the owners manual (which you can download
for free from Roland).

Matt Roberds

Roland Electronic Drums
 

wrote in message
...

I got two of these, one is a TD-7 and one is a TD-8. They seem to respond to
input but do not make sound. The little "trigger" light lights up.

I also have one of another brand that only puts out sound through the
headphone jack.

I am comoing up with a blank finding prints fro these. Anyone know any
common failure oes or whatever, or worked on a bunch of them ? Need a couple
of tips.





First job is to make sure there is +/- 15v on the output op-amps, but you
knew that already.

Each output has a mute (2SC) transistor that shorts the output to ground. I
have found these faulty in the past, possibly damaged by connecting to a
phantom powered input channel.
You can snip through the collectors if there is room, to disable them for a
quick check, or just take them out.

Also have a look at the main and headphone volume pots to see if there is a
signal coming in and out. Most likely the problem is between here and the
outside world, including the final stage op-amps, again possibly damaged by
phantom power. They will have full DC output if toasted.
It is rare to find any problems in the digital/DAC stages.

I suspect what happens in the Phantom Power case, is that the user tries one
output to find it doesn't work, then goes round all the others trying them,
and breaking them too.



Cheers,


Gareth.

Roland Electronic Drums
 

Oh, most of these things have a Demo function for testing/repair, which
should always output audio whatever the internal settings might be.


Gareth.

Roland Electronic Drums
 

On Wed, 6 May 2015, wrote:

I got two of these, one is a TD-7 and one is a TD-8. They seem to
respond to input but do not make sound. The little "trigger" light
lights up.

I also have one of another brand that only puts out sound through the
headphone jack.

I am comoing up with a blank finding prints fro these. Anyone know any
common failure oes or whatever, or worked on a bunch of them ? Need a
couple of tips.

I found one in the garbage, I can't remember the model number.

It didn't work initially, but after I pulled out the connectors and
reconected, it worked fine. So check for that.

Michael