Build Your Own Clone Message Board

Working on the Classic Delay. Have bypass and LED. No signal when switch is enabled. Have reflowed solder a few times (doesnt mean it was done correctly on every solder joint - but it was double checked ).

Also have repeats when the switch is engaged and I tap certain resistors and capacitors - which leads me to believe everything after the PT2399 is working correctly.

My 9V reads on the the TL072 chip are

--|_|--
8.5 --| |-- 9
8.5 --| |-- 8.5
8.2 --| |-- 9
9. --| |-- 0
|------|


https://imgur.com/a/12DaJ7F

Thanks for all the help, been plugging at this sporadically for the past 6 months or so, trying to figure out on my own, finally reaching out for assistance.

Take the TL072 out of its socket and take voltage readings again please. Also, please post pics of the back of your PCB

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Keith - thanks for writing back.

Here is the front and the back of PCB

https://imgur.com/a/kUzlLEh

The TL072 without the chip in it reads like this. The top 2 on the left and the 2nd own on the right both start at about 3V then slowly diminish to 0. The 3rd on the right is always 0

0_____9
0_____0
8.2___0
9_____9

I have some good news for you and some bad news. The good news is I can tell you exactly, with 100% absolute certainty what your problem is. You have a short between the +9V and ground. The bad news is, there are about dozen places on the PCB where this could occur and I can't tell you where. I couldn't see anything in your pic that looked suspicious. You're just going to have to go through with a fine tooth comb (or preferably a magnifying glass) and find it on your own.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

HA! Fine tooth comb it is. A magnifying glass and patience I have.

I understand you cant tell me where it could be - BUT - could you tell me how to find it!

Am I checking each solder joint for 9V?

Look for two solder joints that are touching. That’s about the only way to find a solder bridge.


Sent from my iPhone using Tapatalk

_________________
Pedal building is like the opposite of sex. All the fun stuff happens before you get in the box.

Ahhh - that kind of a short. Gotcha. Thanks!

Finally got it working. Had to swap out the TL072 chip. Put a new one in and POOF it worked as it should. Figured I'd post a resolution.

Great news! Glad it worked out.

_________________
Scott

My band, Austin Hollow

Yes, you can have an internal short in an op amp. Did you accidentally put it in backwards or use a positive tip power supply at some point?

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

"Did you accidentally put it in backwards or use a positive tip power supply at some point?"

of course I did!