coryjrogers Posted March 17, 2012 Report Share Posted March 17, 2012 So after installing all components and a voltage check on the base I installed the CS. There was a pop and smoke. I've been checking parts and levels over and over, during which I noticed the T1 was getting hot. I replaced it and tried the brightness test Wilba described in another post by putting an led in the b+ and b-, this didn't work. I removed the T1 and tested around and discovered that all three pads are shorting to each other. What now?!? :sad: Quote Link to comment Share on other sites More sharing options...
Shuriken Posted March 17, 2012 Report Share Posted March 17, 2012 (edited) Just for reference T1 is the BC337 transistor (which i assume is the currentsink for the front panel leds). I had a quick look at a photo in the build guide. I assume you did a continuity measurement. Since all the pads are directly or indirectly connected to ground i don't think you can conclude the T1 pads are shorted. Did you do Step 2: Voltage Tests on the Control Surface PCB from the build guide without IC's installed? Edited March 17, 2012 by Shuriken Quote Link to comment Share on other sites More sharing options...
coryjrogers Posted March 17, 2012 Author Report Share Posted March 17, 2012 (edited) When I was doing step 2 of the voltage test I heard a pop and saw smoke. Then started problem solving to get figure out what caused the smoke. The over heating bc337 seemed the problem. I don't think the 3 pads should trip continuity on my multimeter. Edited March 17, 2012 by coryjrogers Quote Link to comment Share on other sites More sharing options...
Shuriken Posted March 17, 2012 Report Share Posted March 17, 2012 (edited) I don't think the 3 pads should trip continuity on my multimeter. On an unused pcb it shouldn't. But with the components installed i am pretty sure that R3 and R4a tie the collector and emitter leg to ground :wink: But with closer inspection i see that T1 is used for the LCD. Could you tell me what psu you are using and could you measure it's power output on the psu connector? Edited March 17, 2012 by Shuriken Quote Link to comment Share on other sites More sharing options...
coryjrogers Posted March 17, 2012 Author Report Share Posted March 17, 2012 I'm using the PSU Wilba links to on his page. The Jameco 12vdc 1A regulated psu. http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?freeText=1953663&langId=-1&storeId=10001&productId=1953663&search_type=jamecoall&catalogId=10001&ddkey=http:StoreCatalogDrillDownView Quote Link to comment Share on other sites More sharing options...
Shuriken Posted March 17, 2012 Report Share Posted March 17, 2012 I'm using the PSU Wilba links to on his page. The Jameco 12vdc 1A regulated psu. http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?freeText=1953663&langId=-1&storeId=10001&productId=1953663&search_type=jamecoall&catalogId=10001&ddkey=http:StoreCatalogDrillDownView Ok, that should work without a problem. Since i don't own a Sammichsid and there is no schematic available, i am at a loss here. Just some suggestions: Did you double check that the shunt settings on JBL and JR4 are set correctly for your lcd. Check for shorts on the lcd connector. Quote Link to comment Share on other sites More sharing options...
Melted Hugo Posted April 9, 2012 Report Share Posted April 9, 2012 (edited) Hey coryjrogers, I also had a little trouble with the correct display configuration and shorts that resulted from it. I'm not sure if I set JBL to 5V or 12V (I guess it's 12V as I'm using the high-power LCD), but I remember that I also encountered smoke when putting a shunt in JR4. According to the guide, it shorts R4A which reduces the current for the backlight... After shunting JR4 the LCD was bright and clear but there came smoke out of somewhere. When leaving out the shunt, the display is still lit but quite dark. It runs nice but I still wonder what that could have been that smoked there :/ perhaps you made the same mistake like me... Edited April 9, 2012 by Melted Hugo Quote Link to comment Share on other sites More sharing options...
Gilesjuk Posted April 9, 2012 Report Share Posted April 9, 2012 (edited) There's only one thing that can die and that's the backlight. It's typically a white LED and it can be replaced. The rest of the display is powered from a different set of connections. Edited April 9, 2012 by Gilesjuk Quote Link to comment Share on other sites More sharing options...
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