FM Test tone not working

MIDIbox FM
1

well it helps, but i did a simple continuity test to find the bad pin… more simple ;)  anyway thank you for ur help

by the way i have a new problem with the OPL3, i should start a new topic, but i’ll take advantage of your help in this one if u’r agree  ;D

i chekcked all my voltages: -12 +12 +5 everything seems to be ok

i did all the tests : OPL3 wiring (successful) then Testtone.

(i have only one  YAC chip so i have only outputs 3 & 4 available)

When i run Testtone i got the 1KHz from output 3 but i got a DC voltage (-9V) on output 4 !

i measured -10V at pin#8 of the last TL074 (IC6) !

do u have any idea about this prob ? is my TL074 down ? do i have any other voltage to check to localize my mistake ?

thanks

2

well, as usual i solve my problem less than 1h after my post…  :stuck_out_tongue:

just a bad resistor between IC5 & IC6, i got 1KHz on each output now

topic totally solved  :slight_smile:

3

It might seem advantageous to continue a new problem in an old thread, and maintain momentum/attention… but you need to think about how it effects other people searching the forum for answers… So I split this into a new topic, and I’m going to move it into the FM forum too. Hope that’s OK.

4

nop, u’r right, i known it was a mistake

anyway thanks for the forum  :slight_smile: