Neon C3298DVB stuck in standby

[multimeter]

Re: Neon C3298DVB stuck in standby

Fuse tested ok..do i black probe screw chassis n red probe power i pins on mainboard on continuity setting?
Took the shield off & cant seem to find any info on the ic..thx

for dc voltage testing with power on,dc setting 20v 0n multimeter,black on chassis screw,red on individual out pins on connector.

for resistance /fuse testing power off,either on 200 ohm range or diode test function for continuity.

you will need to remove the heat sink on the cpu chip,should just twist off gently,you will need to get some thermal bonding glue to put back on ,both surfaces must be spotless and dry,use isopropynal alcohol.

the ic will have its part number under the heatsink.

[sienoki]

Re: Neon C3298DVB stuck in standby

also,now you have everything disconnected,plug connectors in one at a time,whilst jumping 5v to on,and monitor the voltages if they dissapear again then what ever you plugged in may have a short on it,im positive more or less its the main board though

Fuse tested ok..do i black probe screw chassis n red probe power i pins on mainboard on continuity setting?
Took the shield off & cant seem to find any info on the ic..thx

[multimeter]

Re: Neon C3298DVB stuck in standby

also,now you have everything disconnected,plug connectors in one at a time,whilst jumping 5v to on,and monitor the voltages if they dissapear again then what ever you plugged in may have a short on it,im positive more or less its the main board though

[multimeter]

Re: Neon C3298DVB stuck in standby

check the fuse ive marked in red,this problem is either a corrupt new eeprom flash that you put in,or the crystal to the cpu has failed or the cpu has failed both of these are under the large sheild ,your power supply seems fine.

check that fuse

if fuse good,take resistance reading on the connector pins of the mainboard(the one where the power comes from the psu),just the ones that are marked with a voltage,the readings should be very high resistance,if they are low ie about 30 ish ohms,then it points to a short on that rail which will need investigating.


if all good then you will need to take off that large sheild and look up the datasheet for the cpu ic,confirm what the voltage into the cpu is and what pin it is,and then test that pin to see if the correct voltage is there,if you dont have a scope then you wont be able to test the crystal,it should show a steady sine wave on a scope.

[sienoki]

Re: Neon C3298DVB stuck in standby

I jumpered the 5v from the stnby pin to on/off pin & still no other voltages..i will get some pics off main board both sides when ive some time off work..thx

I jumped them pins with nowt connected 2 mainboard & 12v/24v appeared..sorry 4 not doing correct 1st time..some pics of mainboard..if you need underside let me know..theres no smd devices on the underside..thx

[sienoki]

Re: Neon C3298DVB stuck in standby

primary side heatsinks will normally be at line voltage so 230v will be on the heatsink,but your large filter cap should be around 320-340v if the pfc front end is working when tv is powerd on.

disconnect main board,jumper 5v to on/off pin,do other voltages come up?,the 12v to main board,and 24v to inverter?something i think on the main board is putting the psu in to protection.

I jumpered the 5v from the stnby pin to on/off pin & still no other voltages..i will get some pics off main board both sides when ive some time off work..thx

[multimeter]

Re: Neon C3298DVB stuck in standby

primary side heatsinks will normally be at line voltage so 230v will be on the heatsink,but your large filter cap should be around 320-340v if the pfc front end is working when tv is powerd on.

disconnect main board,jumper 5v to on/off pin,do other voltages come up?,the 12v to main board,and 24v to inverter?something i think on the main board is putting the psu in to protection.

[sienoki]

Re: Neon C3298DVB stuck in standby

Heres 1 with wires attached..not sure which 1s 2 put a jumper on..thx

I took a reading on the big cap & got 230 on the ac/dc meter & 0 when switched off..the big heat shield also measured that?..is it supposed 2 measure that..thx

[sienoki]

Re: Neon C3298DVB stuck in standby

A pic ok underside psu

Heres 1 with wires attached..not sure which 1s 2 put a jumper on..thx

[sienoki]

Re: Neon C3298DVB stuck in standby

These are best pics i can do 4 now..hope they help..thx

A pic ok underside psu

[sienoki]

Re: Neon C3298DVB stuck in standby

Thx fella 4 sticking by me i really appreciate it..im gonna get good photos sorted soon so i will leave it till then..thx again

These are best pics i can do 4 now..hope they help..thx

[sienoki]

Re: Neon C3298DVB stuck in standby

yes just jump the 5v to the on/off signal ideally with a 3ohm resistor,(but wire should give an indication), which should be to power the psu on,but it may also be the backlight on signal,you may see the backlights come on when the pins are jumperd,need to see the pins really just to check

Thx fella 4 sticking by me i really appreciate it..im gonna get good photos sorted soon so i will leave it till then..thx again

[multimeter]

Re: Neon C3298DVB stuck in standby

Ive no scope fella..the 5v is coming from standby pin & theres an on/off pin next to it..how do i jump them 2 pins?..is it just make a u shape with wire n place it in the connecter block & switch it on then read voltages..thx
Sorry for having no photos & the knowledge for testing & troubleshooting..im gonna get another card reader installed in my pc for my camera..thx

yes just jump the 5v to the on/off signal ideally with a 3ohm resistor,(but wire should give an indication), which should be to power the psu on,but it may also be the backlight on signal,you may see the backlights come on when the pins are jumperd,need to see the pins really just to check

[sienoki]

Re: Neon C3298DVB stuck in standby

there is a good chance then,that the old eeprom may have corrupted the main cpu,do you have a scope?,be good to see if the crystal is working and sending a signal to the cpu,the cpu has to send an"on"signal back to the psu.

the cpu and crystal is under the large metal screening cage,,and the cpu will have its heatsink bonded to the cpu.

also check ,you said you had a live 5v rail,this is proberly the standby voltage,is it marked STB ?,and there should be a pin next to it mark STB_ON or something like that,you can jump those 2 pins and see if the other voltages come up

Ive no scope fella..the 5v is coming from standby pin & theres an on/off pin next to it..how do i jump them 2 pins?..is it just make a u shape with wire n place it in the connecter block & switch it on then read voltages..thx
Sorry for having no photos & the knowledge for testing & troubleshooting..im gonna get another card reader installed in my pc for my camera..thx

[multimeter]

Re: Neon C3298DVB stuck in standby

there is a good chance then,that the old eeprom may have corrupted the main cpu,do you have a scope?,be good to see if the crystal is working and sending a signal to the cpu,the cpu has to send an"on"signal back to the psu.

the cpu and crystal is under the large metal screening cage,,and the cpu will have its heatsink bonded to the cpu.

also check ,you said you had a live 5v rail,this is proberly the standby voltage,is it marked STB ?,and there should be a pin next to it mark STB_ON or something like that,you can jump those 2 pins and see if the other voltages come up

[sienoki]

Re: Neon C3298DVB stuck in standby

have a quick check on the psu ,make sure the fuses are all in tact still,there should be also one smd fuse on the main board it should be white in color,check that also,.

and also try shorting pins 5&6 on the eeprom again,completely unplug tv,short pins(keep shorted),plug tv in,switch on from tv side button power switch,then try and bring out of standby from the remote

Ive done all youve suggested fella & no joy

[multimeter]

Re: Neon C3298DVB stuck in standby

have a quick check on the psu ,make sure the fuses are all in tact still,there should be also one smd fuse on the main board it should be white in color,check that also,.

and also try shorting pins 5&6 on the eeprom again,completely unplug tv,short pins(keep shorted),plug tv in,switch on from tv side button power switch,then try and bring out of standby from the remote

[sienoki]

Re: Neon C3298DVB stuck in standby

this is strange,are you saying you had all the psu voltages before you changed the chip,but now you only have a 5v ?

Yes had all voltages on psu..ive looked over eeprom with jewellers eye n all contacts r perfect..i cut the legs off old 1 to get that 1 off so i cant put that bk on 2 rule out new eeprom

[multimeter]

Re: Neon C3298DVB stuck in standby

this is strange,are you saying you had all the psu voltages before you changed the chip,but now you only have a 5v ?

[sienoki]

Re: Neon C3298DVB stuck in standby

now you have the eeprom fitted press Source> 2580 then scroll to 'RESET ALL,that should do it,if it dosent then there is another problem

Hi fella..i tried that after fitting eeprom & no luck
I aint got a clue now whether its psu or mainboard