April 5, 2017 at 8:46 AM #12223
I attempted to install the audio board. Installation went relatively smoothly, and when I turned it on things seemed normal at first (at this time it was not connected to screen or console, because I was gonna double-check some settings before flashing the audio firmware). But after about 30 s, maybe a minute, the unit froze and didn’t respond to button presses.
I desoldered the board and yes, like a dumbass I had forgotten to check (loss of) ground continuity on the three pads before soldering, and it turned out two of them had not been completely severed (the ones marked I2S and W5). So I fixed that, resoldered the board and checked all other connections for continuity, everything seemed fine.
Turn on the OSSC, and the same symptoms were there, unit hangs after a number of seconds. If I turn it off then on again, it might freeze immediately, or even the LED is blank (lights but no text).
Finally, I removed the audio board and re-grounded the pads with three wires. But, unit still malfunctions like above (again, the first time I power on, it worked the longest before freeze). 🙁
Any guesses at what this can be? Firmware corruption? Damage to IT6613 chip, or solder bridges? (it’s the only one close to any of the soldering, but I checked for bridges and couldn’t find any)April 6, 2017 at 10:42 PM #12267
That shouldn’t have caused any damage. Your symptoms sound like the oscillator has some issue, e.g. a weak connection to PCB (maybe severed while hooking wire to it?).April 9, 2017 at 10:35 AM #12301
Thank you Marqs, I desoldered/resoldered the oscillator pin and now it works again!April 18, 2017 at 3:59 PM #12471
Ok so finally I put in the audio board again, and it seemed to work, I got audio for about 10 minutes, then there were some crackling noise and sound dissappeared. Perhaps stupidly, I left it on to fix some video settings (got a new TV so was pretty eager…) and after about an hour, the unit froze. Turned power off/on, then the screen was lit but blank (similar to previous problem), but additionally, the D1 and D2 LEDs were continuously on (strong red for D1, weak green for D2).
Once again, I removed the board and regrounded pads, and carefully resoldered the crystal pin. However, the problem persists…! Did I finally really break something??
Thanks again in advance for any input on this!April 19, 2017 at 9:59 PM #12499
It’d help debugging if you could either measure the oscillator output or test FPGA via JTAG.April 20, 2017 at 9:06 AM #12505
I have a multimeter, but no USB blaster. I’m gonna need some pointers on which pins to measure, and in what mode. Cheers!April 25, 2017 at 10:42 PM #12592
With multimeter you can measure continuity between oscillator output and FPGA clock input pin, but you’d need a scope to verify that the oscillator is actually working.April 26, 2017 at 8:42 PM #12603
Ok, thanks for the info, I’ll check this weekend. Saw that the part only costs a few euro so maybe I just order it and try it out.
You must be logged in to reply to this topic.