@#$%^&*!!!! rebote!!!!

[pinkjimiphoton]

see, that's the thing....as far as the chip is concerned, it sees the same voltage either way cuz of the regulator.

i'll try using a couple roach clips and a pot. what the heck, lol...

[pappasmurfsharem]

see, that's the thing....as far as the chip is concerned, it sees the same voltage either way cuz of the regulator.

i'll try using a couple roach clips and a pot. what the heck, lol...

Didn't you mention the voltage went up like 1v or something? It shouldn't make a difference I suppose, but what do I know

The suspense is killing me...

PS.

after watching your video I'm jonesing to make a honey dripper. That thing is a BAMF.

[pinkjimiphoton]

if you make a diphonizer, use ronan's idea, and put it in a wah shell...amAzing!!

ok...since last post, i bypassed the switch, same problem. switch isn't it.
replaced the regulator again, because it failed... the 5v side was putting out almost 8. as soon as i power up with battery,
it's fine.
hit it with a wart? same old s***.
i am gonna use my uglyface as an oscillator, and go thru it point by point with my scope...should be a good learning experience, have had the scope forever but have never actually used it before.

near as i can figure, from the symptoms, it's somewhere in the feedback path of the cct...

because the feedback "runs away" when on a wart..

because it is louder than the source signal, that tells me it has to be someplace before one or both of the opamp stages.

because it's a loud hum, it seems dc is getting in with the audio, and amplified.

that screams leaky cap.. but where? and why the heck does it work fine on a battery?

i've replaced/eliminated the jacks, the switch, the regulator, the ic, the 1st stage 47u filter cap, the power supply jack...

i'm wondering if it's maybe the jfet? guess we'll find out...

what a pia!!

[Govmnt_Lacky]

The 5 volt side was putting out almost 8 

That doesn't sound right to me bro.

Shouldn't the 5 volt side be putting out 5 volts?

Is it the same output with battery AND wall wart?

[pinkjimiphoton]

yes, it's the same with the bat or the wart, but i think whatever it is is killing regulators...it reads 5v on the battery, can't leave the adapter hooked up long enough to figure it out...that's why i'm gonna use the o-scope.

the reg in there is a 78l05 at the moment, the third one i've put in in the last 48 hours.

[Ronan]

The reg needs a good ground to work reliably, just check the ground is good.

[pinkjimiphoton]

ground is good as far as i can tell, ian

[Jdansti]

I've had problems with the 78L05 on the PT2399. I know a lot of people haven't had problems and I'm not saying that is your problem, but I just use his big brother, LM7805 by default. I normally don't have to use a heat sink with the big one when using it in place of a 78L05.

BTW, I might have missed it, but do you notice the 78L05's getting hot?

[pinkjimiphoton]

it's the big one with the heat sink, so maybe i'm calling it the wrong thing...
it doesn't get hot, but it does get warm.

[Jdansti]

Got it.

I wonder what could fry 3 LM7805's in short order?

[pinkjimiphoton]

4 now. another roasted, literally as soon as i hook up the wart...it swells in extremely distorted, the echoes runaway, and it fries the damn 2399, too.

i tried hooking up the oscope, but apparently have no idea (apparently??) how to set it up...i can't seem to get a waveform to display on it, or if i do, as soon as i touch any of the dang knobs i lose it. so...oscope may be toast. or something. i dunno.

i have it working again, with my last regulator and it's wack. the 5v side is putting out about 6v, with a 8.48 battery. maybe ALL the regs were defective?

what the hell could draw enough current to roast the regulator AND the chip? i'm thinking it's something with the feedback circuit, but i can't seem to find it.

gonna take out the power jack, and hang the battery snap out of the hole i guess. hate to give up, but this is ridiculous...i've replaced almost everything, and any time i try to test it, it frys everything on the board? i guess i gotta disconnect each component, one at a time, and measure it. but it DOESN'T MAKE ANY FREEKIN' SENSE!!

screw this thing. onwards and upwards.

[Ronan]

I think your wall wart might be knackered.

Have you tried replacing the 7805 and the PT2399 at the same time, and powering up the rebote with the 1-spot or Boss? I know you tried the other 2 wall warts at some stage but that could have been AFTER you toasted the circuit with the 1st wall wart.

Another question - is the said suspect wall wart the very same one you were using live when the rebote 1st stopped working, and, if so, I would guess you don't use said suspect wall wart to power any other pedals. In fact there's a test right there, will said suspect wall wart power a known good pedal? But before you try that test, measure it's output voltage with your DMM set to AC, the AC should read very low, maybe 100mV (0.1V AC) at most. IF that wall wart has a short circuit diode in its rectifier, maybe you are getting some AC, which will quickly kill the 7805, and in turn destroy the PT2399...

Just tryin to help...I could be totally on the wrong trail of course, usually am.

[Jdansti]

I think your wall wart might be knackered..

Another question - is the said suspect wall wart the very same one you were using live when the rebote 1st stopped working, and, if so, I would guess you don't use said suspect wall wart to power any other pedals. In fact there's a test right there, will said suspect wall wart power a known good pedal? But before you try that test, measure it's output voltage with your DMM set to AC, the AC should read very low, maybe 100mV (0.1V AC) at most. IF that wall wart has a short circuit diode in its rectifier, maybe you are getting some AC, which will quickly kill the 7805, and in turn destroy the PT2399...

Just tryin to help...I could be totally on the wrong trail of course, usually am.

FYI -
If you are looking for AC on top of the DC, make sure your DMM measures "RMS" or you'll get funky false readings (been there - done that ).

[Jdansti]

You can run it on a 9v battery connected to the same jack where you plug in your PS, and nothing fries (I think you tried this), but when you connect the PS to the same jack you get crispy critters. Some thoughts:

1) The PS voltage is off or maybe the rectifier in it is bad (you probably checked the voltage).
2) There is a failed component that is causing a large current draw and the battery can't keep up with the demand.  In other words, the current is limited by the battery so no damage, but the PS has a higher current capacity than the battery and it keeps pumping electrons until something becomes toast. Does the battery get warm?
3) Reversed polarity.  Have you replaced the PS cable or male plug lately?

A final thought - Measure the current draw with your DMM set to amps and your meter in series with the positive battery lead and the +Vin.  Maybe someone can give you an estimate of what the Rebote current should be.

[pinkjimiphoton]

I think your wall wart might be knackered.

nope, one's a boss, one's a one spot, and they both work fine on all my other pedals.

Have you tried replacing the 7805 and the PT2399 at the same time, and powering up the rebote with the 1-spot or Boss? I know you tried the other 2 wall warts at some stage but that could have been AFTER you toasted the circuit with the 1st wall wart.

yes, replaced the regulator and the 2399 each several times...went thru all 5 7805's i had here, and 4 2399's. the one spot that powers my pedalboard had no problems with the other 16 pedals on my board, and seems to be fine. i've used 3 other generic warts in the house, as well as the boss and one spot.

Another question - is the said suspect wall wart the very same one you were using live when the rebote 1st stopped working,

no

and, if so, I would guess you don't use said suspect wall wart to power any other pedals.

yes, i do. all the pedals power off the same wart except the ones that need dedicated transformers...tc delay, fuzz face.

In fact there's a test right there, will said suspect wall wart power a known good pedal? But before you try that test, measure it's output voltage with your DMM set to AC, the AC should read very low, maybe 100mV (0.1V AC) at most. IF that wall wart has a short circuit diode in its rectifier, maybe you are getting some AC, which will quickly kill the 7805, and in turn destroy the PT2399...

i'd think it would kill anything else, too...it doesn't tho.

Just tryin to help...I could be totally on the wrong trail of course, usually am.

no worries ian, thanks for trying to help bro!!!!

[pinkjimiphoton]

You can run it on a 9v battery connected to the same jack where you plug in your PS, and nothing fries (I think you tried this), but when you connect the PS to the same jack you get crispy critters. Some thoughts:

1) The PS voltage is off or maybe the rectifier in it is bad (you probably checked the voltage).

yah, i checked the voltage...repeatedly. they all read roughly the same.

2) There is a failed component that is causing a large current draw and the battery can't keep up with the demand.  In other words, the current is limited by the battery so no damage, but the PS has a higher current capacity than the battery and it keeps pumping electrons until something becomes toast. Does the battery get warm?

good possibility...i'm wondering if a momentary power surge or something went up high enough to pop some/all of the 16v electros. i DID find a bad connection on the 10uf cap going to the 4.7k resistor on pin 15. i soldered it up nice and tite, and now i get no hum...an improvement...but the delay doesn't work, tho you can hear it cycling in the background.

another 805 roasted. i'm out. i can't even get a voltage reading off the one in there, but for some reason it's working.

3) Reversed polarity.  Have you replaced the PS cable or male plug lately?

nope. all are set to run on standard, boss-style 2.1mm center negative power. none of the ends is switchable or anything.

A final thought - Measure the current draw with your DMM set to amps and your meter in series with the positive battery lead and the +Vin.  Maybe someone can give you an estimate of what the Rebote current should be.

that's a good idea...i'll try it tomorrow.

i did get the o-scope figured out, using the uglyface as an oscillator. i can see a wave form, and can trace it thru parts of the circuit.. but it dissappears in places, where either resistors or caps are blocking the dc...i think i need to look for AC tho.
i dunno what i'm doing, it's 2:15 am, i give up for the nite.

[deadastronaut]

hi jimi, sorry to hear about your probs...try your 7805's out of the box/circuit to test that you are getting 5v out...on battery, + psu.

but like ian suggested, measure that psu with a DMM first...

if they are ok you know its your board/solder/etc...

[oldschoolanalog]

Put the damned thing down for a couple of days. You need a break from this.
And read through this and familiarize yourself w/the 'scope.
http://www.download-service-manuals.com/en/manual.php?file=Tektronix-1308.pdf
Try probing some known working circuits to get a feel for what things are supposed to look like.
Before going back to work on this clean the board of all flux residue and use a hobby knife to make sure there is really nothing between any of the traces. Also check the component side for any foreign matter that may be between component leads/legs.
But first get away from it for a bit. Sometimes a fresh mindset/perspective makes the issue just jump out at you.
All the Best!

[haveyouseenhim]

Put the damned thing down for a couple of days. You need a break from this.

I would have built a new one by now. I lose my mind on debugs.

[oldschoolanalog]

>I would have built a new one by now. I lose my mind on debugs.<
Having lost my mind decades ago; de-bugging no longer bothers me. I take it as a learning experience.
I do feel your pain however...