The source of the bank with fet 285 has about 87v and the drain of opposite bank has 1.7v.
Led238 is lit.
I have - 7v on both channels.
Setting the gain to midpoint did bring the voltage down to about -1.7v. But moving the gain I can see the voltage on the speaker terminals move around allmost to rail voltage.
Led238 is lit.
I have - 7v on both channels.
Setting the gain to midpoint did bring the voltage down to about -1.7v. But moving the gain I can see the voltage on the speaker terminals move around allmost to rail voltage.
I just realize I have my lamps in series with d444 and d447 in stead of 445 and 447. No wonder the no voltage on the one rail. Il fix that and be back in a few
After getting that right I have 79.4 on one rail and -79.6 on the other. Only about 40mv of dc at both speaker outputs.
I do have audio. I mean doesnt sount like anything but garbage. I can hear the beat but doesnt seem like it has any power. My battery isnt the best. Nothing seems to get too hot or like its drawing a ton of amps. I might need to charge this battery some as its sitting at about 12.10v when the amp is on. I can prolly wire my power supply to it now and it shouldn't act funny.
If I remove input and speakers and fire it up the xformer or whatever is making that high picked noise starts pulsing or changing pitch. Allmost like its oscillating.
If there are no more problems (destroying parts), you can remove the limiters.
Post a photo of the output waveform when driving a 100Hz signal into the amp.
What are you using for a signal source? Is the shield grounded?
Post a photo of the output waveform when driving a 100Hz signal into the amp.
What are you using for a signal source? Is the shield grounded?
I'd expect a signal swinging about 5v, above and below ground.
Are you still driving a signal into the amp?
Confirm that you have both positive and negative 15v on the power terminals (4 and 8) of that IC.
Are you still driving a signal into the amp?
Confirm that you have both positive and negative 15v on the power terminals (4 and 8) of that IC.
The pic of the scope was driving a signal and I just removed signal to check voltage.
Pin 4 has -17.60v
Pin 8 has +14.95v
Pin 4 has -17.60v
Pin 8 has +14.95v
If the signals on pins 5 and 6 weren't close to being identical, I would have expected pin 7 to have a much greater signal level. You wouldn't happen to have a 5532 or any similar op-amp on hand, would you?
You said you didn't work with ICs much. Do you need suggestions replacing (regarding removing) this one?
You said you didn't work with ICs much. Do you need suggestions replacing (regarding removing) this one?
I have a few different op amps on hand, il dig them out.
I have no problem removing and replacing ic's, I don't work with troubleshooting ic's much.
I have no problem removing and replacing ic's, I don't work with troubleshooting ic's much.
I don't think there is a problem with the optocouplers (at this point). The op-amp should have been swinging rail to rail (±15v) but was not.
Man I dont know how I mixed them up. I was prolly still half asleep. I barely have any surface mount components. I have a buddy nearby who hopefully has one. If not il order one soon.
Where did you get confused? When you checked pins 5, 6 and 7, were you checking the op-amp or were you checking an optocoupler?