# 3340 VCO problems **URL:** \ **Category:** DIY STUFF\ **Created:** [May 21, 2021, 4:17pm UTC](https://lookmumnocomputer.discourse.group/t/3340-vco-problems/3536 "2021-05-21T16:17:45Z")\ **Posts on this page:** 1\ **Showing post:** 2
**Author:** ![fredrik](https://yyz2.discourse-cdn.com/free1/user_avatar/lookmumnocomputer.discourse.group/fredrik/32/682_2.png) [@fredrik](https://lookmumnocomputer.discourse.group/u/fredrik)\ **Post date:** [May 21, 2021, 4:35pm UTC](https://lookmumnocomputer.discourse.group/t/3340-vco-problems/3536/2 "2021-05-21T16:35:12Z")
I think you need to provide a bit more details than “isn’t working” because that can mean anything 😀 Have you checked the voltages? > [@Annotated Simple 1V/Oct Oscillator Stripboard](https://lookmumnocomputer.discourse.group/t/annotated-simple-1v-oct-oscillator-stripboard/1267): > > And here’s [the LMNC 3340 stripboard layout](https://www.lookmumnocomputer.com/projects#/cem-3340-diy-simple), with scribbles: See [here](https://lookmumnocomputer.discourse.group/t/annotated-simple-low-pass-filter-stripboard/1266) for the annotated Simple Low Pass Filter stripboard. This guide is about the performance oscillator, but a lot applies to any build: > [@Advice for troubleshooting 3340 based VCO](https://lookmumnocomputer.discourse.group/t/advice-for-troubleshooting-3340-based-vco/2077): > > This is a wiki post; please correct and improve! This is written regarding the 1222 Performance Oscillator module, but similar things apply to the simple stripboard oscillator or other oscillators based on the 3340 chip. For the stripboard version also see If you are not getting good tones from the oscillator, do the following. If with the 1222 you are also not getting good behavior from the tuner, don’t waste time on trying to fix that yet. Get good tones on the outputs first — the tuner won… [This search](https://lookmumnocomputer.discourse.group/search?q=troubleshooting%203340) has more. --- _[View the full topic](https://lookmumnocomputer.discourse.group/t/3340-vco-problems/3536)._