Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 An LED shouldn't need a transistor. Its a diode. As long as you have 0.7V or so of potential over the diode it should light. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 Originally posted by sizzlemeister In other words, these aren't being strobed, are they? It looks like they're static. No, they aren't static. They move with the sequencer. Link to comment Share on other sites More sharing options...
Members sizzlemeister Posted August 13, 2005 Members Share Posted August 13, 2005 Originally posted by urbanscallywag Right. Well, with the 10k resistor in series. I studied them in school like this but I have no idea about the real world. I think you're on to something with the grounding issue. They won't light without an external ground applied to at least 1 of the LEDs. Well, it depends on the PCB layout, but all of these look like they're on the same ground. So, if one's out, I'd imagine all of them are out. I was looking at LED 39 because you said in the other thread it is dim. But, I can't imagine why is the latch is good. Then again, as I said, having you DIRECTLY SOLDER ICs is not the wisest choice IMHO. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 http://www.ladyada.net/make/x0xb0x/releasecandidate.jpg For clarification we're looking at the bottom right. 14 15 16 D U DONE A S are affected. Link to comment Share on other sites More sharing options...
Members sizzlemeister Posted August 13, 2005 Members Share Posted August 13, 2005 Originally posted by urbanscallywag No, they aren't static. They move with the sequencer. No no no no. Bare with me: I cut my teeth on OLD gear. LED arrays would be strobed like a LED digit is strobed. In other words, the latch is on and off on and off as opposed to just on. Forgive my non-technical explanation - I don't have any references open in front of me (out of sight out of mind). The LED is strobed quickly enough that it looks on, hence the reason when the CPU is taxed on older synths the lights and digits sometimes seem to flicker. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 All traces between IC8 and the resistors->LEDs are working. I applied 5V at each pin and gounded them, and they all lit (except for lucky number 39 ).So there is a ground issue, at minimum.What's weird is that even if the diode is grounded, it still doesn't respond to when the CPU should be telling it to turn on. So there's more than just a ground issue.Or, perhaps IC8 isn't functioning right since its not grounded. Time to test for ground continuity. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 Originally posted by sizzlemeister No no no no. Bare with me: I cut my teeth on OLD gear. LED arrays would be strobed like a LED digit is strobed. In other words, the latch is on and off on and off as opposed to just on. Forgive my non-technical explanation - I don't have any references open in front of me (out of sight out of mind).The LED is strobed quickly enough that it looks on, hence the reason when the CPU is taxed on older synths the lights and digits sometimes seem to flicker. Ah, I know what you mean. I believe these are static. Link to comment Share on other sites More sharing options...
Members sizzlemeister Posted August 13, 2005 Members Share Posted August 13, 2005 Originally posted by sizzlemeister What's PIN 9 of IC8 doing on the PCB, is it grounded? IC8 is last in the chain, so I'd immediately suspect pin 9 from IC6 to 14 on IC8. Try jumping that to see. Everything else is serial and that's the only "unique" line relative to your issue here. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 OK, OK! Pin 9 is chillin' all alone. Its on the fast track to no where. No traces. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 Ground, pin 13, seems to have proper ground with the other latches. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 Pin 9 of IC6 and pin 14 of IC8 have continuity.Seems more and more like its a bad IC. Booo.I will have to report to guest. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 Note to everyone:Uncle Sizzle says: USE IC SOCKETS BEFORE I SOLDER THOSE ICS TO YOUR ASS! Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 Goodness, I have LED flicker in 28 now. I think that actually is addressed in an update. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 13, 2005 Author Members Share Posted August 13, 2005 This is just a sick instrument. Link to comment Share on other sites More sharing options...
Members TDman Posted August 13, 2005 Members Share Posted August 13, 2005 A most entertaining thread, keep it up! Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 14, 2005 Author Members Share Posted August 14, 2005 I went to Fry's for a new IC8. They didn't have it. Am I surprised? No. Why did I waste my time?So now I'll do a mail order for a whole bunch of stuff. I was thinking of changing the color of accent and slide LEDs maybe. Or should I just do every 4th step? Or order super bright red as a replacement?I'll probably order some Neutrik stuff, bending toys, LEDs, and the 74595. So I guess I'll have a life for the next couple days...maybe I should do some cleaning. Nah. Link to comment Share on other sites More sharing options...
Members BOBA JFET Posted August 14, 2005 Members Share Posted August 14, 2005 IIRC from my EE classes, you will probably need to change out the resistors for the corresponding LEDs if you change them with brighter ones or different colors, especially blue, white, violet, etc. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 14, 2005 Author Members Share Posted August 14, 2005 Originally posted by BOBA JFET IIRC from my EE classes, you will probably need to change out the resistors for the corresponding LEDs if you change them with brighter ones or different colors, especially blue, white, violet, etc. Yes, I'll have to experiment with R values. Link to comment Share on other sites More sharing options...
Members roblogic Posted August 15, 2005 Members Share Posted August 15, 2005 I finally started mine last night - got the power supply and VCO finished. I can't wait to get this thing running! Link to comment Share on other sites More sharing options...
Members GlassPrisoner Posted August 15, 2005 Members Share Posted August 15, 2005 As long as the Brown Genie doesn't fart.... Link to comment Share on other sites More sharing options...
Members Amos Posted August 15, 2005 Members Share Posted August 15, 2005 I pulled the trigger on my x0x on Friday... now, the anticipation! I hope it's here by Friday the 19th... that's my birfday. Did Limor e-mail you when your kit was actually shipped, or did you just pay and wait for the mail-person to bring you a surprise? Link to comment Share on other sites More sharing options...
Members roblogic Posted August 15, 2005 Members Share Posted August 15, 2005 Originally posted by Amos Did Limor e-mail you when your kit was actually shipped, or did you just pay and wait for the mail-person to bring you a surprise? Yup, got an email with a FedEx tracking #. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 15, 2005 Author Members Share Posted August 15, 2005 Cool Amos + Roblogic!Yes, I got a Fedex number too.I just need to order another IC and some LEDs and I'll be done. I'm depressed that I need another IC. Link to comment Share on other sites More sharing options...
Members urbanscallywag Posted August 30, 2005 Author Members Share Posted August 30, 2005 Yay! I got a replacement latch IC (actually 2) from a fellow x0xb0xer in the mail today. I replaced IC 8 and the LEDs work now!I still have to replace the slide (or accent) that I burned out. But, yay!Unfortuately I scratched the face taking the knobs off, they really stick. Oh well, it was TOO mint to be in my posession before. Now it looks a bit more used. I want to play but I need some sleep. Link to comment Share on other sites More sharing options...
Members Amos Posted August 30, 2005 Members Share Posted August 30, 2005 Congratulations! I'm glad you got it up and running.x0x 096 is in progress now; I'll probably have to wait until the weekend to finish it.edit: arg, that picture was huge! not what I expected; sorry... Link to comment Share on other sites More sharing options...
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