June 11, 2019 at 3:20 pm #6071
My Ratt Deluxe was working great! Then it stopped working. I opened it up, took the parts out made sure all the connections were solid, tested it, it worked again! I put it all back together and I was happy. Then it stopped working again.
I’m clueless as to what could be wrong and what I should do to diagnose it. I’m still pretty new to this whole diy pedal thing. Bypass works as needed, the guitar passes through. When I switch it, the red led lights up happy. But, no sound. I’ve ensured that cords are setup in and out as needed, etc.
I’m attaching photos. Any input would be helpful! – JamesJune 11, 2019 at 5:02 pm #6072
Intermittent signal is usually a case of a loose connection or a short. I see that R5 is socketed. If it works loose, that could cause an open circuit. Check that. Next, try re-soldering all joints. ( Remove power and the IC and transistor first.) You may have a cold solder joint that is turning on and off.
If these fail, try using an audio probe to trace the signal path to find an open or short.June 11, 2019 at 8:48 pm #6074
What Wilkie said (some resistors can have very thin leads) . . . PLUS . . . . I’ve often had socketed trannies work themselves loose. If there is NAY slop in the insertion force needed to get the tranny into the socket, slightly and carefully “wrinkle” the ends of the tranny’s leads so they are not straight when so inserted into their respective socket pockets. The slight ‘wrinkle’ will ensure there is a good connection in the socket(s).June 16, 2019 at 9:10 pm #6097
I’ve tried those recommendations. I’ve also tried a different LM308. Same thing.
I grabbed the voltages from each pin on the IC in case that is helpful in testing things out
8 0mv – 199mv this one constantly climbs then resets to 0June 17, 2019 at 7:01 am #6098
I’d suspect a ground problem with those high readings on your IC or the op amp itself
Zooming in on your ground connection I’d reflow that so it melts nicely onto the pcb pad and DC jack it may well be a poor connection coming loose so check all of your grounds and IC socket pads especially pin 4 ground even though it’s reading 0v your input and output pins 2,3,6 should read around half the supply voltage with ground on 4 and supply voltage to 7, check that the IC is located correctly into its socket
Also take voltage readings with the IC removed from the socket for comparison
You can also wiggle each wire to see if it can be replicated to find any bad connections
As Wilkie says if a socketed component comes loose that would cause problems on a recent Mowah build I had a socketed transistor causing an intermittent fault when the wrong way up it was fine turning it around it crackled then cut out I eventually found one of the legs had broken with me constantly checking voltages
So when I turned it around the broken pin would connect and visa versa dis connect took me a while to suss it it was only when I removed it I saw the pin had broken inside the socket
You must be logged in to reply to this topic.