zoinknoise

thanks for your replies guys. the transistors gave me a lot of grief. re: T1L, the reason it looks like it's installed backwards is because it's not a BC547, it's a PN2222. different pinout. i had totally forgotten about this until you guys pointed it out. the reason it's not the original transistor that shipped with the kit, i believe i installed the original backwards and i damaged it while desoldering. a PN2222 was what was on hand for replacement. the white stuff on the board is probably solder flux from desoldering/resoldering, etc... for what it's worth i may have burned out T1 due to some bad jumper placement... i could smell it when i had the jumpers in the wrong place once. i'm not really sure because before it happened, the board wasn't working properly anyway, so i have no idea. is it worthwhile to test these transistors with my meter? i've never done it before but anyone can lay out how to do it, i'll report back here with the results. or should i just replace all the transistors on this board and see what happens?

Sure thing-- Yes my soldering is pretty messy :tongue: but I'm still fairly new to electronics...

Hi guys, new to the forum...I bought a sammichSID kit from the last batch this summer and after assembling it, still have not gotten it to work properly. I'm certain I've built the synth itself properly as it boots up, display is functional, I was able to load patches into it, etc... however my SIDs are just not functioning right. I have four 6581's lying around here and they all output an extremely quiet and unusable signal when I install them into the sammichSID. I've had people who know a lot more than I do about electronics take a look at the board and they think the chips are just dead, which of course I'm willing to accept. But all four of them? At least one of them was working properly in the C64 it was pulled out of. And they're not all completely dead; they output *something* as quiet as it is. They respond to MIDI input properly, but only one voice seems to work. (I thought the sammichSID was laid out as 6 voices, one per oscillator?) I hear a loud popping sound as I switch patches. I am using the recommended 12V Jameco 1A power supply. I have installed the proper capacitors for 6581's on the board. I've checked and re-checked the jumper configuration on the header pins. Pin 28 on each SID reads 12.45v, and for whatever it's worth, pin 27 reads slightly over 4v (don't know what to make of that). Both SIDs warm up noticeably after powerup but not hot to the touch. Very excited about getting this synth working, so I am grateful for any support re: my problem. Even if the answer is just to get some new SIDs. Are mine finished or could something else be the cause of my woes?