or can I please tell me if I can control the voltage on IC1. For example, on contacts 30,31,65 ..... then it may be possible to understand what turns off the amplifier
I understand that if the voltage is more than on the circuit, the amplifier goes into protection, for example, if there is 0.6v on pin 31 and not 0.4v, it will turn off
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Have a better look at what I posted on a previous page, its a subset of "Q317 to Q376", not 60 transistors.
Then I've also noticed a temperature sense.
Any of such may raise an error condition.
Then the CPU may run checks with the other big QFP chips. If the error is raising so, via bus or chips diagnostics, it will be difficult to solve.
This is why I added in a previous post that at the end, you may pull out only transformer plus amplifier board, to be fit in an alternate box. You may so get at least a 5 channels or 2 channels brided amplifier out of that.
Then I've also noticed a temperature sense.
Any of such may raise an error condition.
Then the CPU may run checks with the other big QFP chips. If the error is raising so, via bus or chips diagnostics, it will be difficult to solve.
This is why I added in a previous post that at the end, you may pull out only transformer plus amplifier board, to be fit in an alternate box. You may so get at least a 5 channels or 2 channels brided amplifier out of that.
> How I can veryfied pins 30,31,34,65,69 ?
I said do not kill the CPU I/Os! Check all the circuits behind them
I said do not kill the CPU I/Os! Check all the circuits behind them
Just my two cents, complicated, 25 years old cinema processor, send it to the garbage bin, and buy a new one, will be probably cheaper than trying to fix it in the dark. Cinema processors changed a lot since the last 25 years, new codex, new standards, probably yours doesn’t even have HDMI, etc.
So probably not worth the trouble…
SB
So probably not worth the trouble…
SB
Hello guys.
I verified all connections,all soldering,and I replaced c21 and IC5.
Amplifier works fine.
Thank you very very much
I verified all connections,all soldering,and I replaced c21 and IC5.
Amplifier works fine.
Thank you very very much
I've worked on quite a few of these. The main problem is dry joints in the PSU and also on the volume control PCB. That'll solve most problems. The PCB's are also very thin and brittle and can break if the amp has been dropped.