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Equipment Repairs => LCD TV forum => Topic started by: pike on April 07, 2012,14:21:11

Title: Acoustic Solutions LCD32761HDF Power Supply Overload
Post by: pike on April 07, 2012,14:21:11

Hi, Have a problem with my TV. It won't switch on (most of the time) :bedtime2:. Attempting to switch on from standby results in standby again after a moment or so. I've checked the PSU, voltages, caps, shorted diodes etc. nothing. I also have another fault in that I have no audio. I use a pair of amplified PC speakers. I believe the audio amplifier (where-ever it is, I've hunted!) has a stuffed output stage as Ive noticed one speaker gets warm. There's about 11v across the warm speaker (The other appears normal but no audio). Unplugging the internal speakers has an great effect on switch-on performance thus leading me to believe the power supply is sensing the defective Audio amplifier IC failure and switching off the TV. So, does anyone know where this amplifier IC is. There's a 20pin sms ic near to audio output caps, inductors etc, doesn't get hot nor can i understand the various chinese sites that appear when i try to search for the ic. anyone got a circuit for the audio stage??

Title: Re: Acoustic Solutions LCD32761HDF Power Supply Overload
Post by: jordan on April 07, 2012,15:58:51

This typ LCD use two typs chassis Vestel 17MB123  and 17MB351 and two diverse PSU 17PW26 and 17PW263
This audio procesor is MP7722  
??? service manual
My be its problem on PSU (C-852 ...1000uF/35V)

Title: Re: Acoustic Solutions LCD32761HDF Power Supply Overload
Post by: pike on April 09, 2012,06:39:58

Thank you..  :yahoo:

Title: Re: Acoustic Solutions LCD32761HDF Power Supply Overload
Post by: kimhthwy1958 on April 23, 2012,09:52:20

Hi, I have this same telly and it keeps turning itself of as i think it is getting to hot could you tell me which part or parts are causing this and is it an easy fix please. Here are the pictures of the inside. Thank you inadvance.

Title: Re: Acoustic Solutions LCD32761HDF Power Supply Overload
Post by: watteau on April 25, 2012,03:40:18

Hi,
Most common fault for this are the two, 15nf 630v capacitors(C878, and C877),  near the large transformer on the power-supply they go open circuit, but sometimes there can be poor solder connections on them,
CHS stock them, 13007CH  £1.88.
Regards,
John.

Title: Re: Acoustic Solutions LCD32761HDF Power Supply Overload
Post by: kimhthwy1958 on April 25, 2012,05:05:32

Thank you for your reply is it possible to point them out on the picture and also i need to know the value of the capacitor as maplins don't know the 15nf 630v if that makes sense.

Title: Re: Acoustic Solutions LCD32761HDF Power Supply Overload
Post by: watteau on April 25, 2012,06:38:57

Hi,
The values are 15 nanofarad, 630 volt working,
I don't know if Maplins stock these, but CHS (Charles Hyde & Son) do.
See photo.
Regards