ohhh got it.... the volts/div mechanism.... How do i take it out?
Please don't mix match.. otherwise troubleshooting become exponentially bizarre ! hahaha ha LOL
ok... replaced them parts and nothing happened. I went ahead and replaced the whole attenuator board with one from another scope and though the traces were completely out of the screen I could actually move channel 1 trace with the vertical position knob with the beam find button pressed. Then put back the original board because I still want to repair it.
Voltages are the same.
Yeah... but what i did there is actually to replace the whole board... the whole circuit board. the whole thing
but only for a brief moment to see what happened.
The voltage at the JFET is not right.
For capacitors from 1000uf to 1nf and no leak? You mean the oil evaporated away? unlikely LOL.
So either leak onto PCB, Ghost hunt or attenuator problem.
The voltage at the JFET is not right.
For capacitors from 1000uf to 1nf and no leak? You mean the oil evaporated away? unlikely LOL.
So either leak onto PCB, Ghost hunt or attenuator problem.
If I put ch1 in DC mode and measure dc voltage at the probe input I get 2.4VDC not so in ch2 But that´s probably coming from pin7 in Q13...
I doubt its the caps because I changed them for the ones from a working unit....
The voltage at the JFET is not right.
For capacitors from 1000uf to 1nf and no leak? You mean the oil evaporated away? unlikely LOL.
So either leak onto PCB, Ghost hunt or attenuator problem.
If I put ch1 in DC mode and measure dc voltage at the probe input I get 2.4VDC not so in ch2 But that´s probably coming from pin7 in Q13...
Could be possible, then change new nfet for Q13A.
I doubt its the caps because I changed them for the ones from a working unit....
At least you should have measured the capacitance and ESR before plugging it in?
I doubt its the caps because I changed them for the ones from a working unit....
At least you should have measured the capacitance and ESR before plugging it in?
I dont know how to measure ESR... I just started a year ago building guitar amplifiers, and when I started I didn´t knew the difference of positive voltage and negative (not kidding), so this is rocket science to me Lol
Screw it, I´m gonna change that Q13 and see what happens.
I doubt its the caps because I changed them for the ones from a working unit....
At least you should have measured the capacitance and ESR before plugging it in?
I dont know how to measure ESR... I just started a year ago building guitar amplifiers, and when I started I didn´t knew the difference of positive voltage and negative (not kidding), so this is rocket science to me Lol
Measure, check, verify or you'll end up just chasing your tail.
Methodical processes need be employed....
I doubt its the caps because I changed them for the ones from a working unit....
At least you should have measured the capacitance and ESR before plugging it in?
I dont know how to measure ESR... I just started a year ago building guitar amplifiers, and when I started I didn´t knew the difference of positive voltage and negative (not kidding), so this is rocket science to me Lol
You got good soldering and desoldering skills I would say..... I think you are pretty good at electronics .. at the very least you have the courage to hands-on...
I doubt its the caps because I changed them for the ones from a working unit....
At least you should have measured the capacitance and ESR before plugging it in?
I dont know how to measure ESR... I just started a year ago building guitar amplifiers, and when I started I didn´t knew the difference of positive voltage and negative (not kidding), so this is rocket science to me Lol
You got good soldering and desoldering skills I would say..... I think you are pretty good at electronics .. at the very least you have the courage to hands-on...
I`m a high end jeweller by day and amp builder by night... I know how to work with tiny stuff
Damn... how do I desolder the fet.... that`s a hard one
Yep.... it is the fet. Took it out, tested it and there is conductance between pin 7 and pin six... it should read open.
IT Wooooooooooooooooooooooooooooorksssssssssssssssss!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Yeeeehaaaaw!
Thanks Armadillo! You`ve been most helpful
I hope to have the opportunity to give you a hand as well someday.
Now I need to calibrate this thing because it`s a mess. Volts x10 in channel 1 is completely out of whack.
Hopefully there won`t be no more surprises.
Mr Dean and Ben next.
Yessir! Tomorrow I start bringing Mr. Dean back to life! ...screwed up power supply I guess.
