Samsung LE37C630 need schematics

[yoritomo]

Hello all

I have a TV to repair Samsung LE37C630 with a mainboard problem, it is often stopping and restarting by itself when warm, sometime The Led lit, sometime not, I guess about a reset circuit problem but without schematic it is quite difficult task to resolve. It has a reset button on the mainboard , I was searching some problems there but no success.

The mainboard reference is : bn41-01443A

I have been searching everywhere on my favourite free schematics websites without luck, Eservice info, electromaniacs, elektrotanya, monitor.net.ru ...
I could find the service manual, but does not contains any schematics, how comes ...

Looks like some powers disappears as 1.5 1.8 and 1.2v but i need to verify with a schema.

Thank you for your help

[Diah]

Re: Samsung LE37C630 need schematics

you checked on MB voltage of L202,L203,L204 disappeared after it turn off, did you check L201 remain had 3.3V. and did the PWB remain support the standby or it cut it. try freeze the Power IC regulator near to the above mentioned test points

[dick_barton]

Re: Samsung LE37C630 need schematics

Is this the problem you are describing?
https://youtu.be/aET6KWVRagQ

Have you disconnected the power supply from the mainboard and checked that all the voltages are present when you connect Power_ON to standby voltage and that they stay on?

Perhaps you could supply photo's of your boards which would be helpful.

[yoritomo]

Re: Samsung LE37C630 need schematics

Thanks Diah, i will check these values to be sure on friday because tomorrow is the national day here in Belgium, The tv set still in my labo.
As i could see only 3.3V still on always, but i will confirm soon. As well i will check by oscilloscope, drop downs can makes differences.
Could you find the schematic then ? I wonder where

dick_barton yes it is exactly the symptom of that tv set. +5 Stand by looks always good. There is a good quality picture of similar board from the net http://www.duycom.com/wp-content/upl...N94-02625K.jpg

[yoritomo]

[solved] Samsung LE37C630 need schematics

hello all

I did not reply since last time because, the tv was in test period, as i can see the problem it is resolved, no more problems until now.

The reset button on the main board was definitely the cause, i was careful about it because i am aware by experience about the poor quality of Samsung switch buttons which are getting oxydation to fast usually.

The best way to clean it is to soak in isopropanol, ultrasonic cleaner is a good option too for the lateral function keyboard of Samsung.