Sunday 12 February 2017

Line 6 DL4 final fix

A short update on my DL4 that had come back from the dead but wouldn't run as a DL4.

I went through 3 replacement DRAM chips and none of them worked. With all of them I got distorted noise instead of a delay signal. Yesterday I sat down with a schematic and beeped out every pin of the DRAM to the DSP. The RAS line (pin 45) of the DSP wasn't quite soldered down, so the RAS pin at the memory was open. Some flux and a quick touch of the soldering iron and now it works with external memory and runs the DL4 firmware correctly.


New RAM chip. The flux mess was cleaned off afterwards.

The DRAM that I know worked was a Toshiba TC51V17805CFTS-60. I think any 16 Mbit DRAM with the same standard pinout will probably work here.



5 comments:

  1. Hello, I'm looking to sell my non-working Voodoo Lab Tremolo pedal, and you seem like the perfect person to ask. Are you interested? I didn't have your email, but you can contact me at goldfisher08@gmail.com. Thanks!

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    1. Sorry, but I am not really looking to buy any projects right now, unless they are very unusual/interesting. I'm busy enough that I have a backlog of stuff to repair and another backlog of stuff to write about.

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    2. I've fixed one before, try a new VTL5C3 opto if you still have it, got mine going! be careful, the circuit board traces are fragile in Voodoo Lab stuff.

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  2. Replies
    1. I was wondering how long it would take before the spammers started commenting.

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