Faulty Mytek stereo96 ADC buffer IC sleuthing.

[mrclunk]

This Mytek convertor's been on the healing shelf for years and i'd like to get it fixed.

It seems to be a problem with the input buffer stage before the ADC, two of the IC's (U4 and U5) are burning up after powers applied.
Unfortunately the component markings have been sanded off and Mytek won't tell me what the IC are... (The date codes on the bottom are 08A21 = OCT2008)
One channel was working, but with all my poking around i've killed that channel too!

It uses a TI PCM4202 ADC. The datasheet example for this ADC uses OPA1632 differential opamps for the buffers but the power pins don't match the Mytek.
I've searched for differential opamps with power pins on 4 and 8, as on the Mytek PCB with no luck..
It looks to me like a dual opamp would fit the bill but all this is way over my head..

I've traced out the Mytek input circuit, hopefully someone can point me in the right direction.
If anyone can please help me work out these parts i would be a very happy boy!

 

[Khron]

Do Analog Devices make any diff-in/diff-out opamps? Not sure if (or how often) TI marks the date codes on the bottom of the chips...

 

[mrclunk]

Do Analog Devices make any diff-in/diff-out opamps? Not sure if (or how often) TI marks the date codes on the bottom of the chips...

Thanks, I did go thru the AD catalogue looking for diff amps but again the power pins didn’t match. Possibly could be a discontinued part tho?
All the other ic are TI, so would be some logic to a TI part.

 

[Khron]

You could consider removing the burning(?) chips and verifying their supply rails are at sensible levels, to begin with.

U8 is the Vcom buffer?

 

[mrclunk]

You could consider removing the burning(?) chips and verifying their supply rails are at sensible levels, to begin with.

I have, rails are ok.

U8 is the Vcom buffer?

The bottom circled ic is the vcom buffer. It's actually U5, not clear on the pic.