Results 1 to 3 of 3

Thread: Fixing Roland BR900-CD digital studio recorder

  1. #1
    Join Date
    Aug 2019
    Thumbs Up/Down
    Received: 0/0
    Given: 0/0
    Rep Power

    Fixing Roland BR900-CD digital studio recorder

    I am struggling to fix older piece of audio equipment BR900-CD. I have disassembled it to replace a pot, and after reassembly it wont boot. After powering on you can see LCD animation, some LED light up and fade slowly (like power went off), and everything hangs - nothing works. Also LCD backlight works no more.

    I have compared voltages on some ribbon connectors and before when it was still working voltages were slightly higher than now. For example: 3.60 -> 3.12, 4.56 -> 4.21, 8.24 -> 7.88.

    Original input is 9V DC. It is converted down the road by voltage regulators to 5V and 3.3V.

    Any clues what can cause that voltage drop ? Is it rather cause or the effect ? How could I go about to troubleshoot it ?

    Unfortunatelly schematic is impossible to find.

    0 Not allowed! Not allowed!

  2. #2
    Supporting Member
    Join Date
    Dec 2009
    Thumbs Up/Down
    Received: 385/0
    Given: 59/0
    Rep Power
    Maybe the 3.12v is below the threshold voltage for the main CPU, but I'm just guessing. You could try contacting Roland for a schematic, or preferably the service manual. At the time it was manufactured there must have been some supporting documentation for their service centres.

    Have you re-traced the steps you took when replacing the pot to make sure a connector isn't reversed or 1 pin out, or even if you have a solder bridge somewhere? All it needs is a tiny bead to bridge tracks and you've got a fault.

    Before you replaced the pot did everything (apart from the pot) work correctly?

    0 Not allowed! Not allowed!

  3. #3
    Old Timer olddawg's Avatar
    Join Date
    Dec 2007
    La Jolla CA, Hanalei, Kauai
    Thumbs Up/Down
    Received: 342/0
    Given: 36/1
    Rep Power
    Usually.. old digital stuff from that era are plagued with failing surface mount electrolytic caps. Got an ESR meter?

    0 Not allowed! Not allowed!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Replies: 0
    Last Post: 08-22-2019, 04:10 AM
  2. A good deal on a digital recorder- Stupid Deal of the Day
    By Steve A. in forum Fun with computers
    Replies: 2
    Last Post: 12-28-2013, 09:16 PM
  3. Fixing hum in Roland Cube 60
    By DavidB in forum Maintenance, Troubleshooting & Repair
    Replies: 6
    Last Post: 10-23-2010, 09:49 AM
  4. Roland Studio Bass 100
    By Carlosraj in forum Maintenance, Troubleshooting & Repair
    Replies: 3
    Last Post: 04-24-2010, 01:33 PM
  5. Roland Studio 6V troubleshooting question
    By Garydean in forum Maintenance, Troubleshooting & Repair
    Replies: 2
    Last Post: 10-17-2008, 01:04 AM


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts