# Prophet 600 voice issue

**URL:** <https://forums.syntaur.com/t/prophet-600-voice-issue/7020>\
**Category:** Synth Repair\
**Created:** [April 2, 2024, 3:58pm UTC](https://forums.syntaur.com/t/prophet-600-voice-issue/7020 "2024-04-02T15:58:12Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Erik\_2319](https://forums.syntaur.com/letter_avatar_proxy/v4/letter/e/e8c25b/32.png) [@Erik\_2319](https://forums.syntaur.com/u/Erik_2319)\
**Post date:** [April 2, 2024, 3:58pm UTC](https://forums.syntaur.com/t/prophet-600-voice-issue/7020/1 "2024-04-02T15:58:12Z")

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Hi,  
I’ve recently started working on a friends Prophet 600 that sat in his basement for the past 10+ years. I noticed right off the bat the keyboard needed some work so cleaned it and got the keys working regularly. I also installed the gligli mod which was easy and fixed a lot of issues it was having previously (programs from 01-30 were not working) but then noticed a new thing going on. When I turn it on and give it time to warm up (10-30 mins) I run the tune and notice when it gets to the 6th voice for A, B and F the keyboard only displays 6 and then the letter and then 6 again separately before continuing to the next voice or filters. I also noticed when I play it if I start on a note and play C-D-E-F-G the following note (no matter where) won’t make a sound. If I hit the key again though it works and starts the pattern over. I’m curious if this problem lies with the GliGli modification or if the voice chips are damaged/not working on voice 6.

Any help is great and I am relatively new to refurbishing synths so any troubleshooting tips are appreciated as well!