wavecircle Posted August 18, 2011 Report Share Posted August 18, 2011 Hahaha, this didn't take long. The bottom buttons work fine, I can navigate the pages no problem and the esc and arrow buttons work fine too. The encoder and the top buttons do not work. I am guessing that the two 165 chips route to the 595. My presumption is that the top 165 is missing a connection or isnt working. Would that be right? I don't think I need to troubleshoot the bottom set of buttons because they seem to work fine. Again, should I just resolder all the joints relating to the top 165 chip? Quote Link to comment Share on other sites More sharing options...
m00dawg Posted August 18, 2011 Report Share Posted August 18, 2011 Yes, I would simply "reflow" solder on those pins, although you can also check for continuity using a multimeter before you do that as well. I had a cold solder joint I wasn't able to spot with my eyes for my sammichSID. Had to end up cutting tracks to find it :/ The problem would have been easily solved by just reflowing solder on the joint (in other words, I should have tried that first). Quote Link to comment Share on other sites More sharing options...
nebula Posted August 18, 2011 Report Share Posted August 18, 2011 And now, a word from the solder-technique nazi: When "reflowing" a solder joint, you should always either: (a) apply flux first, or (b) add a small amount of flux-cored solder to the joint. Flux is like the magic elixir of soldering. It removes contaminants and small amounts of oxidization on the metals to be joined, and carries it away. If your solder joint was poor in the first place, there is an good chance that it is due to insufficient heat, or because the flux in the solder did not reach the required surfaces. Oxidization occurs on metals like copper very quickly, so adding flux will greatly improve the likelihood that the solder will bond properly when re-heated. It also prevents the joint from becoming contaminated. Just sayin ... :) Quote Link to comment Share on other sites More sharing options...
m00dawg Posted August 18, 2011 Report Share Posted August 18, 2011 Yep good points! Quote Link to comment Share on other sites More sharing options...
wavecircle Posted August 18, 2011 Author Report Share Posted August 18, 2011 Hmm, I just resoldered all the relevant points using flux, still doesn't work. It's ironic really because the soldering on the bottom buttons is worse than the buttons on the top but the bottom buttons work fine. I swapped the 165 ICs round and that didnt change anything so I know the ICs work. Is it possible that I have burned out the transistors? Would that effect the encoder and top buttons? Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted August 18, 2011 Report Share Posted August 18, 2011 (edited) Hm, i am not totally sure, but have you checked the orientation of the shift register ICs? I think I can remember, that there was one, that was oriented the other way round (but that memory could be wrong as well). Greets, Peter Edited August 18, 2011 by Hawkeye Quote Link to comment Share on other sites More sharing options...
wavecircle Posted August 18, 2011 Author Report Share Posted August 18, 2011 Notches in the IC are aligned with the notch marking on the PCB. Very frustrating. Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted August 18, 2011 Report Share Posted August 18, 2011 The next step is usually, that we´d need sharp high-res (2k x 1.5k pixel) pics of the front and backside... maybe it is something obvious to other Sammich FM users... Quote Link to comment Share on other sites More sharing options...
m00dawg Posted August 18, 2011 Report Share Posted August 18, 2011 It could be one of the transistors but that's not all that common, particularly if you followed Wilba's advice for managing heat as per the build guide. Have you tried testing continuity yet? Quote Link to comment Share on other sites More sharing options...
wavecircle Posted August 18, 2011 Author Report Share Posted August 18, 2011 My multimeter doesnt have continuity testing I dont think. I've never done it before, how is it done? Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted August 18, 2011 Report Share Posted August 18, 2011 You can test continuity by measuring resistance... if it reads 0 ohms, there is continuity :-) Greets, Peter Quote Link to comment Share on other sites More sharing options...
m00dawg Posted August 18, 2011 Report Share Posted August 18, 2011 It's the mode that beeps usually by the other resistance tests (if you have a dial on your tester). I would be surprise if you didn't have one on your tester but stranger things are abounds in the world. The easiest way to test for it is to make the probes touch and try the different modes on your multimeter. The one that beeps is probably the one you're looking for. If you find that, then try it on a known good trace (like one of the ones for the top buttons) to make sure it works as it should. Then go to town testing all the end points around the bottom buttons to make sure everything is beeping at you. When testing pins on the sockets, remove the ICs and test on the top (that way you can test the solder joint for the socket easier). Just be sure you don't push down hard or it can bend the contact that comes in contact with the leg of the IC itself. Quote Link to comment Share on other sites More sharing options...
wavecircle Posted August 18, 2011 Author Report Share Posted August 18, 2011 Where would I do these tests? Do I need to power the device up? Quote Link to comment Share on other sites More sharing options...
m00dawg Posted August 18, 2011 Report Share Posted August 18, 2011 No, device should be off for continuity. You're just testing to see that there is a sufficient connection between two points (no shorts). You would test any any pins, via, etc. along the path. So start at a button, follow the trace from it to the next item (like the pin of the IC socket) and test there. Also test the other leg to make sure it is grounded by putting the probe there and on any exposed pin or joint that goes to ground. Stuff like that. You can always start with the paths that work (like the top buttons) so you can get the hang of what I'm trying to explain (albeit I'm doing a poor job :P) since you know those are good connections. Quote Link to comment Share on other sites More sharing options...
wavecircle Posted August 18, 2011 Author Report Share Posted August 18, 2011 My multimeter doesnt have a continuity beep, I have tried the diode mode which is the closest thing ive got. It's really hard to follow the tracks with the board fully populated. I'm going to throw this thing in the river. Quote Link to comment Share on other sites More sharing options...
m00dawg Posted August 18, 2011 Report Share Posted August 18, 2011 If you're in the states, take a quick trip to RatShack (Radio Shack) and pick one up for about $20. They also have a magnifying glass and things there too in order to help you trace the tracks, although there sammichFM schematic is around somewhere (I suspect on the wiki but I'm not 100% sure). Quote Link to comment Share on other sites More sharing options...
wavecircle Posted August 19, 2011 Author Report Share Posted August 19, 2011 The sound doesnt output properly either. There must be something fundamentally wrong with the way I am making this thing to have so many problems. Any one wanna buy it off me? Quote Link to comment Share on other sites More sharing options...
wavecircle Posted August 19, 2011 Author Report Share Posted August 19, 2011 (edited) Right, I've figured out what I think is wrong with my technique. It's basically the solder I am using. It is 99.3% tin and 0.7% copper and at 1mm thickness. In order to melt this quickly I have found that I need my iron to be around 300C. What I think is happening is that the pads are getting overheated/damaged and I am therefore not getting a good connection with the solder. Would this sound reasonable? I believe that 60% tin and 40% lead melts at a much lower temperature, reducing the risk of pad and track damage? I will probably have to buy another sammichFM :( Edited August 19, 2011 by wavecircle Quote Link to comment Share on other sites More sharing options...
Hawkeye Posted August 19, 2011 Report Share Posted August 19, 2011 * are the pads coming off? if not, there is nothing lost, yet. * connection tests are possible with your multimeter without beeper in "resistance measuring mode" 0 ohms = connectivity * hi-res pictures of front (with populated ICs) and backside would be interesting to evaluate what is wrong. greets, Peter Quote Link to comment Share on other sites More sharing options...
wavecircle Posted August 19, 2011 Author Report Share Posted August 19, 2011 I think the pads are intact, it's very hard to do the continuity because the board has tracks on both sides and it is fully populated. I would need a schematic to see what should be going where. I took the Sammich down to my EE friend and he said the soldering isnt up to scratch as I was using too thick and the wrong kind of solder, hopefully he can fix it. Quote Link to comment Share on other sites More sharing options...
Wilba Posted August 19, 2011 Report Share Posted August 19, 2011 Don't throw it in the river!!! Send it to nILS for proper disposal. Or keep at it and fix it. BTW I noticed I have not uploaded the control surface PCB layout as PDF. It's up now, and referenced in the wiki: http://www.mb6582.org/sammichFM/sammichFM_CS_PCB_Rev_1.pdf Quote Link to comment Share on other sites More sharing options...
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