The resistors won't be the problem. The clock is presenting a 5 volt "squarewave" to the input of the unpowered gates and has the ability to propagate internally through the unpowered chip and so develop voltages elsewhere.
This shows one of the gates from that invertor package. Look what happens when you apply 5 volts (the clock input) to the input of the gate, when that gate is unpowered. There is a direct path from the input via the "top" protection diode into the Vcc rail. The clock signal powers and can hold the circuitry on that rail in an indeterminate state.
This shows one of the gates from that invertor package. Look what happens when you apply 5 volts (the clock input) to the input of the gate, when that gate is unpowered. There is a direct path from the input via the "top" protection diode into the Vcc rail. The clock signal powers and can hold the circuitry on that rail in an indeterminate state.
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Thanks Mooly,
still a little beyond my comprehension, but I wonder whether you may consider that U206 could possibly be faulty? Unless something has happened to the clock, there was never a problem with it before.
Also, I think I mentioned that this player had a slightly erratic startup from when I got it, before anything was touched.
Nothing drastic; just mainly booting up with drawer opening and sometimes not seeing TOC.
I had a busy weekend so didn't manage to change to crystal but it is still running nicely so the temptation of playing around with it further was not overwhelming😀
I'll brave the temptation next weekend.
Regards,
Pete
still a little beyond my comprehension, but I wonder whether you may consider that U206 could possibly be faulty? Unless something has happened to the clock, there was never a problem with it before.
Also, I think I mentioned that this player had a slightly erratic startup from when I got it, before anything was touched.
Nothing drastic; just mainly booting up with drawer opening and sometimes not seeing TOC.
I had a busy weekend so didn't manage to change to crystal but it is still running nicely so the temptation of playing around with it further was not overwhelming😀
I'll brave the temptation next weekend.
Regards,
Pete
Well anything is possible but I really wouldn't suspect the invertor package at all.
When you mention problems "booting up with the drawer opening", well things like that are more often mechanical such as intermittent micro switches on the drawer/mech that just need a quick clean. Pictures in post #1 here show such an issue,
http://www.diyaudio.com/forums/digital-source/226288-sony-cdp790-kss240-restoration-project.html
When you mention problems "booting up with the drawer opening", well things like that are more often mechanical such as intermittent micro switches on the drawer/mech that just need a quick clean. Pictures in post #1 here show such an issue,
http://www.diyaudio.com/forums/digital-source/226288-sony-cdp790-kss240-restoration-project.html
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