hisense 55K321UW help please

[rotorwayrichard]

hi guys , i am looking for assistance with my hisense 55K321UW , stuck on standby , ie light on , but pushing power button has no response , occasionally i can get it to power up and all is perfect until i switch it off again , then only standby light is active and nothing else , internal boards are RSAG7.820 6135 ROH for main board , RSAG7.820 6106 ROH power supply and T-CON is RSAG7.820 6125 ROH , if anyone can give me some directions please post and i will do my best to follow the instructions as well as i can , our local agents cannot supply parts as they say it is discontinued so i am a little jammed , it is around 6 and a half years old
Any assistance will be greatly appreciated
Rich

[nomoresonys]

Re: hisense 55K321UW help please

Try a simple test, heat the electrolytic capacitors on the powerboard for a couple few minutes, then try the tv, see if it reacts any better for a bit.

[rotorwayrichard]

Re: hisense 55K321UW help please

thank you for your response , i will give it a try and post results , cheers

[nomoresonys]

Re: hisense 55K321UW help please

Can also look the solder joints on the bottom of the board over very closely and reflow any that look suspect, being careful not to bridge any, need to be careful what you touch the big caps can hold a charge for a quite while 400 volts CAN KILL, can check them with a multimeter, here's an article on the subject, I don't recommend using a screwdriver, when a resistor is simple to use and safer for the board: https://clevercreations.org/how-to-d...e-a-capacitor/

[nomoresonys]

Re: hisense 55K321UW help please

Examples of bad solder joints there: https://www.google.com/search?q=bad+...ih=607&dpr=1.5

[jsdffxf]

Re: hisense 55K321UW help please

What is the model of the master control? According to your description, the EMMC may be defective, which needs to be checked by the serial port tool

[rotorwayrichard]

Re: hisense 55K321UW help please

thanks guys , i tried heating up the electrolytic caps on the power board but no change or response , i will take a closer look at the solder joints aswell on the board , frustrating as when i get it to power onn occasionally by the pulling the power cable , holding the power button down for 30 seconds etc etc , sometimes it powers right up and works flawlessly for hours until i switch ot off back to standby , then all i get is the standby light on again , i have noticed the mainboard processor heatsink being warm when testing it , not sure if that means much ,
jsdffxf , master control ?? sorry i am still learning the lingo here ??