Look at the protection IC datasheet, see what the input is looking for. Is the input voltage or current good or bad? if the input is in spec, the output of the IC should not be trying to drive the relay. If input good, output bad, its the IC. If IC output is good, but relay still protects, something wrong in the relay driver circuit.
If your have trouble reading the voltages around the IC without shorting pins (damages things) get a Pamona minigrabber probe or something. usually it is better to grab component leads connected to the IC, than the IC pins itself - harder to short two things together.
If you are new to electronics debug with the power on, remember the basic safety rules. Power on, use only one hand, current that doesn't cross your heart won't stop it. Use a clip lead on the negative meter lead to speaker ground or some similar convenient point. Wear no jewelry on hands, neck, fingers. 1 vdc at dozens of amps out of an e-cap can burn your flesh to charcoal. Don't work alone, don't work distracted by entertainment devices or other people. To avoid blowing up transistors, causing shrapnle, use a light bulb box in series with the amp AC source while debugging. 100 W bulb (incandescent) series mains AC usually okay for amps under 300 W/ch. Capture AC leads which might fly around inside a grounded metal box, don't get injured by your "safety" device.
If your have trouble reading the voltages around the IC without shorting pins (damages things) get a Pamona minigrabber probe or something. usually it is better to grab component leads connected to the IC, than the IC pins itself - harder to short two things together.
If you are new to electronics debug with the power on, remember the basic safety rules. Power on, use only one hand, current that doesn't cross your heart won't stop it. Use a clip lead on the negative meter lead to speaker ground or some similar convenient point. Wear no jewelry on hands, neck, fingers. 1 vdc at dozens of amps out of an e-cap can burn your flesh to charcoal. Don't work alone, don't work distracted by entertainment devices or other people. To avoid blowing up transistors, causing shrapnle, use a light bulb box in series with the amp AC source while debugging. 100 W bulb (incandescent) series mains AC usually okay for amps under 300 W/ch. Capture AC leads which might fly around inside a grounded metal box, don't get injured by your "safety" device.
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The Amplifier is working now, I ordered 5 ICs from China and finally received them, installed it and it works both in Stereo and Bridged mode.
I measured the DC offset on the outputs and one is a bit higher than the other but I think I can live with that, its only 12mV and the other is 2mV.
Thanks a lot Indianajo for all your help and excellent advise during this process.
Now I will continue with the next beast that's in my project list.
Adcom GFA-5800 Broken Left Channel
I measured the DC offset on the outputs and one is a bit higher than the other but I think I can live with that, its only 12mV and the other is 2mV.
Thanks a lot Indianajo for all your help and excellent advise during this process.
Now I will continue with the next beast that's in my project list.
Adcom GFA-5800 Broken Left Channel
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