3Vpp switching noise on switchmode bench PSU

[king.oslo]

Hello there,

I've got a XHR-150-7 150V 7AMP PSU. Recently I noticed some serious 3Vpp switching noise on the output. Think I will pop it open in a few days to check for problems. What is the common corporate causing problems like these?

Thanks.

Kind regards,
Marius

[Paul Price]

Large valued electrolytic capacitors (directly at the output? or HV mains post rectifier?  have developed high ESR, outgassing or open. Look for the dead cap signature: any sign of the tops being domed shaped, bulging...should be perfectly flat in a healthy electrolytic.

[David_AVD]

Also make sure that you're really measuring that noise on the output.  Dave did a video recently where the signal shown on the scope was actually induced by another switch-mode power supply that was running nearby.