Electronics > Repair

Lecroy Waverunner 64Xi-A no power

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coromonadalix:
i would have said they are allen based ??   i dont see the usual rivet stuff,  i could be wrong,  i saw once  allen key center hole ??

but stupid design indeed     :--


oh  member joeqsmith had some fun in a similar scope
https://www.eevblog.com/forum/testgear/teledyne-lecroy-waverunner-64xi/


is it possible to ask him if he still as this puppy and maybe just maybe  probe the green wires ?

analogRF:
since someone had asked ,when I apply 3.3V to the output of that rail it takes in 74mA.
there is a 51 ohm resistor across the output of that rail. Multimeter also measures around 44 ohm though

i think I will remove the caps first but i highly doubt them to be bad. they look ok and they are nichicon

output msfet switches (paralleled) are not short or anything.
my guess is that they dont have their gate voltage and that comes from the daughter board  :palm:

coromonadalix:
caps seems fine on the photos, i would not touch them at 1st

check  the previous answer while i was writing, you posted ...

cracked solders,  daughter cards  pins ?? ...

analogRF:

--- Quote from: coromonadalix on November 28, 2024, 05:12:12 pm ---i would have said they are allen based ??   i dont see the usual rivet stuff,  i could be wrong,  i saw once  allen key center hole ??

but stupid design indeed     :--


oh  member joeqsmith had some fun in a similar scope
https://www.eevblog.com/forum/testgear/teledyne-lecroy-waverunner-64xi/


is it possible to ask him if he still as this puppy and maybe just maybe  probe the green wires ?

--- End quote ---

Yes they are some sort of rivets but with no end cap on the other side because the heatsink surface has to be flat. No allen key screw.

yes I have seen his thread. it's ironic that when he was posting those messages my scope was being manufactured at factory!
so I think our scopes are at least 7-8 years apart if not more

I have traced the green wires and they are indeed OR'ed together with diodes and 1k pull-ups to the 5V standby.
So definitely both need to be grounded to turn this thing on. One on the acq board and one is the usual ATX PS_ON on the CPU board


analogRF:
I have seen two people who had failed output diodes in their power supply but on the -3.3V which is fine in my case
it could be the diode in my case but the thing is it is parallel with a 51 ohm resistor and thus not possible to test in circuit.
all i can say is that it is not shorted.
the other one which is not parallel to the resistor checks fine in circuit

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