Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to sci.electronics.repair
|
|||
|
|||
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. |
#2
Posted to sci.electronics.repair
|
|||
|
|||
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 |
#3
Posted to sci.electronics.repair
|
|||
|
|||
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 |
#4
Posted to sci.electronics.repair
|
|||
|
|||
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. |
#5
Posted to sci.electronics.repair
|
|||
|
|||
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. |
#6
Posted to sci.electronics.repair
|
|||
|
|||
Roland Electronic Drums
|
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Boss TU-120 Electronic Tuner Schematic Roland LED Strobe Guitar Tuning | Electronics Repair | |||
How to get rid of 55 gal drums of gas | Metalworking | |||
Roland HP-860 electronic piano has HUM | Electronics Repair | |||
Plastic Drums | Metalworking | |||
FA: Electronic Music Machine Kit - Electronic Doorbell, Car Horn - (built, tested) - (one day left) | Electronics |