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Is it the IC or something else?

So with that last problem solves, I can put it all back together. I did add a cooling fan to the power supply to keep it cool. I know its often best to try and keep things passive, but I couldn't see a simple and effective way to improve passive cooling of over six voltage regulators on the board. The cooling fan is a 12V 12cm Computer cooling fan so its quite small and there is a 12V supply that I can take a feed from. I ran some of the power cables over the top of the fan to help keep them away from the power supply. By doing this, it helps keep the power cables away to improve airflow, and holds the cooling fan in place.

With the case on, it creates a gentle draft upwards through the top cover grill. I'll just have to monitor dust build up.

I chose a quiet fan and you can't hear the fan noise over any musical content at a low volume so that seems good. More importantly, the power supply has dropped from over 100°C to around 40°C! :music:
 

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Yes, I thought that too... however, I'm starting to wonder if I don't remember seeing an unsoldered joint... likely Pin 19.... when I first started working on the amp.... It's possible... your avatar is quite relevant I think.... :confused:
 
does every setting seem to be doing its thing ? am just wondering if you found a different fault and masked it .
 
Yes, all the functions work as they should. I did wonder if Pin 19 was responsible for the muting (-20dB) function but it isn't. It's just another disabled group of switches.
 
Thread resurrection here.
I have not one, but two of these sitting on my bench with frozen functions, as per photo, the volume is at max and none of the function buttons work when the unit is powered on.
The output display works if I inject a signal indicating that the display driver is working, so I'm assuming that either the logic has a fault of it's not receiving any feedback info?
I have been searching for a service manual but to date havent been able to find one, any help would be appreciated with the manual or re; the freezing issue
 

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The power supply is very tortured in this unit. Have you carefully checked all the voltages. From memory, I think there might be 11 power supplies or more... If any of the logic supplies, or the reset circuit aren't happy, you wont get any logic, and no response from controls. Looks to me like the CPU isn't booting so check the power supply first. CAREFULLY.

Use a DBT, and don't measure a voltage where there is a risk you'll slip. You need a service manual.
 
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