Dirtbaby LED limiting

[claytushaywood]

I unfortunately missed out on the dirtbaby's short stock and I went ahead and tried the LED limiting mod on my deep blue delay... unfortunately I think its killing my pt2399's.

i am definitely going from pin 7 to pin4.

will this mod work on a deep blue clone?  or do i need to do something else to the circuit?

[Matt]

Connect it to pin 3. Pin 4 is not ground on the deep blue

[sturgeo]

Pin 4 is not ground on the deep blue

Whilst that is strictly true for the original, a lot of people connect 3&4 to GND as this fixes an issue with certain PT2399 chips.

[midwayfair]

Make sure you have the anode on pin 7, and make sure that your pin4 is actually connected to analog ground.

[Muadzin]

*Checks upon Dirtbaby pdf*

*realizes what he has missed*

[claytushaywood]

well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone

[selfdestroyer]

well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone

Chin up man, I get more than that bad in one tayda order :]

Cody

[madbean]

well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone

I don't understand how this is possible. I don't doubt it, but are you sure they are fried and not temporarily locked up somehow? Have you tried grounding all the pins and re-checking it? What are the exact voltage measurements you get on pins 7, 3 and 4?

[claytushaywood]

I have no idea about locking up pt2399s!  How exactly would I go about grounding each pin? Just individually connect.each pin to ground while powered on?

[Matt]

Pin 4 is not ground on the deep blue

Whilst that is strictly true for the original, a lot of people connect 3&4 to GND as this fixes an issue with certain PT2399 chips.

I wasn't aware of this, thanks.

[claytushaywood]

well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone

I don't understand how this is possible. I don't doubt it, but are you sure they are fried and not temporarily locked up somehow? Have you tried grounding all the pins and re-checking it? What are the exact voltage measurements you get on pins 7, 3 and 4?

sorry I forgot to quote you on my last post-

how do i unlock the pt2399?  Do I just hook up the deep blue to my breadboard and power it then use a jumper cable to go to ground on the pins individually?

[midwayfair]

well i just quadrupled checked everything- got a new LED confirmed positive and negative legs.  confirmed pin 4 goes to ground.  put positive of the LED to pin 7 and negative to pin 4.  (both pin 3 and 4 connected to each other) 

and i fried another pt2399... that's 4 good pt2399's gone

I don't understand how this is possible. I don't doubt it, but are you sure they are fried and not temporarily locked up somehow? Have you tried grounding all the pins and re-checking it? What are the exact voltage measurements you get on pins 7, 3 and 4?

sorry I forgot to quote you on my last post-

how do i unlock the pt2399?  Do I just hook up the deep blue to my breadboard and power it then use a jumper cable to go to ground on the pins individually?

Often the chips will unlock after a day or two on their own. Your breadboard idea would be fine. I don't think you necessarily have to ground all the pins simultaneously, it's just to remove any stored capacitance. (Which drains over time, hence why I said that they usually unlock on their own after a day or two.)

I can't think of anything about the LED mod that would do what you've described. It simply conducts when the voltage on pin 7 rises to ~1.8V or higher, and it's been done in about 5 different designs now.

[culturejam]

Often the chips will unlock after a day or two on their own.

Interesting.

Whenever I've had a PT lock up, I kill power to the whole circuit, wait 10-15 seconds, and power back up. Seems to solve the issue.

[atreidesheir]

*Checks upon Dirtbaby pdf*

*realizes what he has missed*

me toooooooo!

[claytushaywood]

Often the chips will unlock after a day or two on their own.

Interesting.

Whenever I've had a PT lock up, I kill power to the whole circuit, wait 10-15 seconds, and power back up. Seems to solve the issue.

thanks.  i promise you i am doing everything correctly.  i've tried it 4 times over about 3 days checking connections, checking LED's, having working pt2399's to begin with, checking voltages, everything.  its not exactly a difficult thing to do.

and now my pt2399s dont work.  ill check em tomorrow to see if theyve unlocked or if theyre donezo. 

I believe I'm using those terribly dim LED's that tayda used to carry (maybe still does) and I used a 3mm diffused green LED.