Mulja tv repair portal

Equipment Repairs => LCD TV forum => Topic started by: t1412 on September 25, 2015,07:18:40

Title: samsung 37
Post by: t1412 on September 25, 2015,07:18:40

morning fella's, just fitted a blank on this Samsung 37   the tv still keeps going off, when i'm trying to do adjustments in the service menu this is the first time I've replaced one what am I doing wrong thanks

shaun   

Title: Re: samsung 37
Post by: Keith on September 25, 2015,08:27:40

It can take a minute or so for the processor to detect the blank eeprom and write data to it. If you turned the set off during this process, you could be back to square one, as the eeprom may have corrupt data again!

If you can get into the service menu you should select reset before you do anything else.

What is the model number of the set?

Keith

Title: Re: samsung 37
Post by: t1412 on September 25, 2015,12:16:52

hi keith it's a le37m86bd thanks

Title: Re: samsung 37
Post by: Keith on September 26, 2015,09:16:04

Check all power supply lines are correct and clean, if the 3v3 line measures 3v1 it's wrong! Check for SDA SCL signals at start up.
If there were originally some faulty capacitors in the power supply it is highly possible that the firmware / boot loader has become corrupt, this is not stored in the eeprom. A replacement main board will be required. A fault in any circuit connected to the SDA and SCL can cause problems, unfortunately replacing a board at a time is the easiest way to find this.
Also check that the oscillators are running at the correct frequencies.
I will upload the service manual, but I need to compress it so it is small enough for the site.

Keith

I notice the manual is already in the download section.

Title: Re: samsung 37
Post by: t1412 on September 26, 2015,11:27:08

thanks for the info keith, when i selected calibration it does say dtv failure, has they say it's the first time for eveything, cheers ps it had 5 bulging caps, cheers

shaun

  

Title: Re: samsung 37
Post by: Keith on September 29, 2015,06:43:05

If the set is starting up, I would check all psu lines, the low voltage supplies are critical, but you need to know your meter is accurate. If 3v3 measures anything else it is faulty, also check 1v8 lines and 2v5 lines. i have not looked at the manual so don't know how many regulators there are. A replacement main board may be the best option!

Keith

Title: Re: samsung 37
Post by: t1412 on October 01, 2015,07:07:02

hello keith here the voltages that are present, 3.3v, the 13v's are 12.46. 5.4, pin 18 of the connection from the power board should be another 13v but it's showing 0023v, the 12v is 12.6v 

shaun      

Title: Re: samsung 37
Post by: Keith on October 02, 2015,06:35:40

What about the 1.2V, 1.25V and 2.5V supplies?

Remove the large screening can and check for corrosion on the board caused by capacitors leaking.

Keith

Title: Re: samsung 37
Post by: t1412 on October 02, 2015,07:01:14

the fella who owns the tv just message me wants it back for spares, I think your right in the first place keith, the mainboard is having a bad time, I've repaired the 40's with the same fault, just shorted the eeprom and service setting and they've worked ok, might have been underline problem, thanks for your help and time   

shaun