Sony KDL-32EX400 fault finding

[budm]

Re: Sony KDL-32EX400 fault finding

ok here's some before and after! almost everything, i was too tired to complete tonight. i've copied the old values into this post.

BEFORE WITH BAD IC6301

------ STBY | POWER ON
C6325 340V 340V
C6117 7.75V 13.45V
C6118 8.05V 13.89V
Vcc @ CXA3809m 7.77V (stby) 13.48V (on)
Pin2 (mode)@ CXA3809m** 0.3mV (stby) -24.3mV (on)
pin3 (AC_detin) @ CXA3809m** 0.601V (stby) 0.576 (drops)
T-Con VCC, REG 12V, UNREG 12V, all 0v or close enough stby or on.

AFTER IC6301 SONY A3809 REPLACED

------ STBY | POWER ON
C6325 339V 394V
C6117 12.45V 14.02V
C6118 12.41V 14.34V
Vcc @ CXA3809m 12.44V (stby) 14.04V (on)
Pin2 (mode)@ CXA3809m** 12.38V (stby) 93.8mV (on)
pin3 (AC_detin) @ CXA3809m** 5.36V (meter on DC) 1.83V (meter on AC)

Secondary voltages to follow when i've had a sleep

Thanks!

[t4796]

Re: Sony KDL-32EX400 fault finding

As per my posting, standby voltage was clearly a lot higher with the working ic, acdetin was up to 6v from 0.6v, and as predicted by you budm the mode voltage was at vcc in standby mode with a working IC

Here's the document I found with a repair process. It mentions adding the two diodes. I notice on the hires screenshots of the power supply board ending in -12 on shopjimmy (mine ends with -11) these diodes are present!

Here's the spanish doc as promised. If I take any more measurements they'll be when I reopen the tv to fit the two additional diodes.

Would anyone be able to theorise the reason they have been added?



cheers!

[PowerAmpFreak]

Re: Sony KDL-32EX400 fault finding

I would expect those two diodes will act as clamping devices, making the chip more robust to handle transients.

[budm]

Re: Sony KDL-32EX400 fault finding

As per my posting, standby voltage was clearly a lot higher with the working ic, acdetin was up to 6v from 0.6v, and as predicted by you budm the mode voltage was at vcc in standby mode with a working IC

Here's the document I found with a repair process. It mentions adding the two diodes. I notice on the hires screenshots of the power supply board ending in -12 on shopjimmy (mine ends with -11) these diodes are present!

Here's the spanish doc as promised. If I take any more measurements they'll be when I reopen the tv to fit the two additional diodes.

Would anyone be able to theorise the reason they have been added

cheers!

Does it says which pin of the IC or where the two diodes are connected too?
BTW, thanks for the info.