thoughts on Digitech Space Station eprom copying?

Started by Processaurus, June 07, 2007, 10:02:50 PM

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Govmnt_Lacky

#460
Quote from: slacker775 on July 03, 2015, 06:36:49 PM
I finally got me xp-all completed but I have a slight odd problem.  For background, I burned my own eeprom, the switch seems to be working right, the appropriate LEDs light up and the program's seem to switch properly.  What I am not getting is any effect output.  I did not yet do the output volume mod.  I get dry signal on the 100, 200, and 400 modes but nothing out of 300.  Tuner, bypass, calibration modes all seem to work as expected.  Could it be the eeprom?  Perhaps the wiring around r30?  Any suggestions?

Suggestion = Pics  ;)

First of all... when the mod is working, and even without the output volume mod, you should NOT get dry signal out of ANY of the XP modes (except the XP100 and only when you do the super duper Dino relay mod) When in XP100 mode, you should only get wet output from one of the jacks and nothing from the other. When in the other 3 modes, you should get effected output on both jacks. The only time you should get dry signal is in BP mode.

Tuner and Calibration mode are all functions of the CPU. Not the EEPROM.

Which pedal did you mod? Throw up a good pic of the full mod and we will see.  ;)

EDIT: Throw up the pics. Need to see WHICH mod you did and how it was done.
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slacker775

Ok, I did the xp-all mod from an xp-100 base.  It sounds like perhaps I might want to reload the eeprom.   Here are some pics:













Govmnt_Lacky

OK... full disclosure.... I have not yet done a mod with the 1001 chip. I always do them with the EEPROMs stacked and no Dry signal when in 100 mode.

Now... with that... some suggestions:

1) Definitely make sure your rotary wiring is correct. Verify each and every wire is going where it is supposed to go.
2) Check for a constant short on your R30 wires. This could definitely cause you to get dry signal out of the left output (when looking down at the pedal from top) when in all of the modes.
3) That left-most RAM chip looks odd. Never seen one like that before. I will be curious to see how the different RAM speeds will interact (when you get it all up and running)

Check these and let us know  ;)
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slacker775

The leftmost ram chip is the one that came with the unit.   The other 3 are ebays from China and could certainly be suspect.    I'll verify that r30 isn't shorted.   I did use the little via for one of the wires that happens to be next to r30.  I verified conductivity beforehand so I think that should be ok

Govmnt_Lacky

R30 should ONLY be shorted when in XP100 mode. On the other modes, the continuity between those 2 wires should be OPEN.
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

Govmnt_Lacky

DUDE!!!!!!!

WHERE IS C63?  :o 390nF

Just noticed this. You have to have that installed for the pedal to work!  8)
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
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slacker775

I do have continuity at r30 though with no power to the pedal.   Def no shorts, but not sure how the relay would be in that situation.    As for c63, I did notice that but forgot to ask.  I know it's marked in one of the pics, but what actually goes there I don't think was covered in the doc.   I'll give that another look-see

Govmnt_Lacky

Quote from: slacker775 on July 03, 2015, 09:07:35 PM
I do have continuity at r30 though with no power to the pedal.   Def no shorts, but not sure how the relay would be in that situation.    As for c63, I did notice that but forgot to ask.  I know it's marked in one of the pics, but what actually goes there I don't think was covered in the doc.   I'll give that another look-see

The only time you should see continuity through R30 is when it is in XP100 mode. PERIOD. If you are seeing continuity with no power... and in every mode on the rotary... you have a problem there.

Without C63 installed, you will NEVER get an effected signal in the stereo output (except in XP100 mode, when properly working... in which case it will only be dry signal)
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
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slacker775

Shoot, c63 is the .390 cap.   I'll put that in tomorrow and double check r30

slacker775

Almost thought I didn't have any 390 caps but it turns out I did get some when I was going thru the BOM for the xp-all.  I put that in at C63, and disconnected one of the wires to R30 (I'm thinking it may be a bum relay since I have continuity at all switch positions, even with power off).  With the relay out of the mix, I do not have continuity between the two R30 solder points.

The good news is - it's working!  I'll check the other relays that came in my batch and see if they all are wonky or what, but that's not a big show-stopper.

Govmnt_Lacky

Quote from: slacker775 on July 04, 2015, 11:09:05 AM
The good news is - it's working!  I'll check the other relays that came in my batch and see if they all are wonky or what, but that's not a big show-stopper.

Awesome! Another XP ALL is born...  :icon_lol:
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
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mongo


Ok, I tried ram chips with the XP 200 and the 4 ram chips I tested WORKED with the XP200. Switched to the XP300 EEPROM and the noise and nastyness are back.

Sooo, time to dismount the PCB AGAIN and test continuity and the soldering of the chips sockets, other than that, I'm out of ideas.

Mongo


Quote from: Govmnt_Lacky on July 01, 2015, 08:25:25 PM
Quote from: slacker on July 01, 2015, 11:13:09 AM
I would try it with the XP200 chip and a ram chip in only the U19 socket, swap ram chips in the U19 socket until you find 4 that work, then at least you know you have 4 good ram chips.

Yep! That's what Dino and I were suggesting earlier.

Govmnt_Lacky

#472
Quote from: mongo on July 05, 2015, 09:13:09 AM
Sooo, time to dismount the PCB AGAIN and test continuity and the soldering of the chips sockets, other than that, I'm out of ideas.

Simple... if you don't find a soldering problem with the U16, 17, or 18 chip sockets then it looks like your XP300 EEPROM is a dud  :icon_frown:

EDIT: Just remember, the XP200 programs ONLY use the U19 RAM chip. So, if you did not swap in each individual RAM chip into the U19 spot when you were testing with the XP200 EEPROM then you really did not verify each and every RAM. You would need to install the XP200 EEPROM and try only 1 of the RAM in U19 and leave the others unpopulated and test. If good, then swap in a different RAM into U19 and test. Repeat until all of the RAM chips are tested. If all of the RAM work, by themselves, witht he XP200 chip.... then your XP300 EEPROM is bad.
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

mongo

Quote from: Govmnt_Lacky on July 05, 2015, 10:12:12 AM
Quote from: mongo on July 05, 2015, 09:13:09 AM
Sooo, time to dismount the PCB AGAIN and test continuity and the soldering of the chips sockets, other than that, I'm out of ideas.

Simple... if you don't find a soldering problem with the U16, 17, or 18 chip sockets then it looks like your XP300 EEPROM is a dud  :icon_frown:

EDIT: Just remember, the XP200 programs ONLY use the U19 RAM chip. So, if you did not swap in each individual RAM chip into the U19 spot when you were testing with the XP200 EEPROM then you really did not verify each and every RAM. You would need to install the XP200 EEPROM and try only 1 of the RAM in U19 and leave the others unpopulated and test. If good, then swap in a different RAM into U19 and test. Repeat until all of the RAM chips are tested. If all of the RAM work, by themselves, witht he XP200 chip.... then your XP300 EEPROM is bad.


I did exactly that: test every RAM chip in the U19 slot with the XP200 EEPROM. It worked everytime. I'll check out my soldering and continuity and report back. Thanks!

Govmnt_Lacky

Quote from: mongo on July 05, 2015, 05:39:36 PM
I did exactly that: test every RAM chip in the U19 slot with the XP200 EEPROM. It worked everytime. I'll check out my soldering and continuity and report back. Thanks!

Cool!

So, it is either a soldering mistake on the U16, U17, and/or U18 sockets -OR- the XP300 EEPROM is bad (my bet)

Good Luck
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
for an amount of 'up to and including my life.'

mongo


Wont have time to test before a week I think, in the meantime, could someone here re-burn my EEPROMS in case those are the problem? or test them at least?

Thanx!

Mongo

digi2t

Quote from: mongo on July 06, 2015, 11:34:57 AM

Wont have time to test before a week I think, in the meantime, could someone here re-burn my EEPROMS in case those are the problem? or test them at least?

Thanx!

Mongo

I can do that, but I'm in Canada. If interested, PM me.
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Govmnt_Lacky

I could do it BUT... I'm in the US and shipping might be prohibitive.

Maybe try "marmaliser" I believe he can burn chips and is in the EU as well. Worth a shot  ;)
A Veteran is someone who, at one point in his or her life, wrote a blank check made payable to The United States of America
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the3secondrule

I've searched pretty thoroughly and didn't find an answer, but apologies if I've missed it:

Is there any reason to specifically use Tantalum caps over any other type of polarised cap (electrolytics)??

Cheers,

J
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digi2t

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