*Please help* GRUNDIG GULCD37HDIT wont turn on

[multimeter]

Re: *Please help* GRUNDIG GULCD37HDIT wont turn on

if thats the case then,either the inverter is causing the 24v to drop out while its connected to the psu due to a fault on it,id be inclined to pull the 24v line out of the connector,and inject 24v from bench supply into the 24v cable to inverter,and jumpering bl_on to its stby voltage to at least check backlights are fine and inverter,after checking shorts to ground on it.

then do resistance tests on the 24v pin at the inverter cable end for shorts,then checking components back along that trace for problems,it maybe one of the out put diodes coming off the smpt that supply's that rail is shorted or open.

i wasnt sure if the 24v should be present if the bl_on signal was 0v,i trust tom's judgement
,so im taking his word as a baseline.

earlier in the thread it was pointing to mainboard failiure,but def seems like a psu fault
which is good news as they are easier to fix

[simple-me]

Re: *Please help* GRUNDIG GULCD37HDIT wont turn on

Multimeter.....should I look at replacing the PSU?

[multimeter]

Re: *Please help* GRUNDIG GULCD37HDIT wont turn on

Multimeter.....should I look at replacing the PSU?

if you have limited test equipment and/or no experience,then id say yes,get another psu,from a trusted seller,with a returns policy

making sure you match the part numbers

some say "tested"working,but id take that with a pinch of salt.....

[simple-me]

Re: *Please help* GRUNDIG GULCD37HDIT wont turn on

I'll check around for pn# 3122 133 33122 PLCD 190 PT3 23341 and report back later...thanks

[simple-me]

Re: *Please help* GRUNDIG GULCD37HDIT wont turn on

No 24v on any of the inverter cables

Correction...

I do get 24v on the white inverter cables when all the wiring is connected up!

[simple-me]

Re: *Please help* GRUNDIG GULCD37HDIT wont turn on

hello all,
I got a replacement psu and tried this but the tv will still not turn on!??

[simple-me]

Re: *Please help* GRUNDIG GULCD37HDIT wont turn on

Got the tv working...after some serious technical help!

Thank you Tom66

Here's how it happened...

Replaced LDO U713, part 1117-33.

Output voltage was unstable 1.3V to 1.7V, changing when power button pressed. No shorts on output. Temporary bodge job connected 3.3V from one part of board to other - set then powered up.

Freeze-spraying regulator did not affect performance.

After this test showed signs of life, regulator was replaced with Farnell P/N# 1469051 and TV worked perfect after that.

[tom66]

Re: *Please help* GRUNDIG GULCD37HDIT wont turn on

Free TV repair in return for curry :P

BTW, forgot to note, the regulator was supposed to output 3.3V. Found another regulator outputting that so tied them together for a brief test and it worked.

[simple-me]

Re: *Please help* GRUNDIG GULCD37HDIT wont turn on

Free TV repair in return for curry :P

BTW, forgot to note, the regulator was supposed to output 3.3V. Found another regulator outputting that so tied them together for a brief test and it worked.

Was a little spicy but you survived it :P

Thanks for your help mate...