Sansui B-1000 - Stuck in protect

[002]

Hi all - hoping to get some help with a Sansui B-1000 power amp that is stuck in protect mode (relay not engaging on power on).
So far I have checked:

• Power supply voltages - all good
• Output transistors isolated and tested - all good
• Most electrolytics - all seem healthy enough

Here are the voltages of IC1 on the power amp circuit which is an STK3082 voltage amplifier:

1. -160mV
2. -180mV
3. +55V
4. +55V
5. -1.1V
6. +1.3V
7. -55V
8. 0
9. +55V
10. +1.3V
11. -1.1V
12. +55V
13. +55V
14. -175mV
15. -172mV

And here are the voltages on IC1 in the protect circuit which is a TA7317P:

1. -570mV
2. 0
3. 0
4. 0
5. -800mV
6. +17V
7. +2.3V
8. +36mV
9. +3.13V

So I believe it's pin 6 of the TA7317P that is holding the relay open?
Anyone got any suggestions on where would be a good place to go from where I am now? Here's a schematic excerpt:

 

[002]

I had a feeling it was the TA7317P chip as it caused me problems in another JVC amp I worked on in the past.
I got some replacements and dropped one in, and it solved the problem. Interestingly enough (despite the amp behaving and running fine now) it has the same quirk that the JVC had with the replacement TA7317P whereby it immediately engages the relay on power-on.
I found another thread with the same issue described but in that case, it was a 1uF cap on pin 8 in the amp schematic versus 22uF in the TA7317P datasheet. In my case, I already have a 33uF cap on pin 8 as per my excerpt above. I experimented with a 10uF and a 100uF in that position but it didn't change the behaviour. In any case, it now works with the caveat that there's no muting delay on power on.