usp440m-42lp psu

[joehezzer]

Re: usp440m-42lp psu

i recently just did one of theese, managed to get a psu from ebay for £30 delievered, the one i had , b/r shorted and a load of mosfets ,so got another board
http://www.ebay.co.uk/itm/4004140660...84.m1497.l2649
it wasnt really worth doing but my missus likes the tv an for keeping her quiet............... priceless

Is that the same psu

[wills123]

Re: usp440m-42lp psu

its not exactly the same but i found it was an equivilant for the one i had, i think it was shopjimmy listed is an equiviliant, you would have to double your part number against it

[joehezzer]

Re: usp440m-42lp psu

its not exactly the same but i found it was an equivilant for the one i had, i think it was shopjimmy listed is an equiviliant, you would have to double your part number against it

ok just had a look at shopjimmy and that is the substitute part have you the same 42" plasma screen !!!!

[paulstef]

Re: usp440m-42lp psu

Joe,

could you do me a favor and measure the voltage over ZD501 and ZD502?

I'm having the same problem but at least VA and all low voltages are working now after I swapped some caps.

Thanks

See my thread here:https://www.badcaps.net/forum/showthread.php?t=36026

[joehezzer]

Re: usp440m-42lp psu

Joe,

could you do me a favor and measure the voltage over ZD501 and ZD502?

I'm having the same problem but at least VA and all low voltages are working now after I swapped some caps.

Thanks

See my thread here:https://www.badcaps.net/forum/showthread.php?t=36026

hi paul yes will give it a go bud, but the problem i have i have no voltage anywhere, i do not even have a standby light nothing, i am wondering if something on the hot side of the board is dead, hence no power any where else, i will check for u though just incase

[paulstef]

Re: usp440m-42lp psu

In post #14 you said you have 5VCtrl. You should also have 5Vsb.

What comes out of the PFC?

If you have 5Vsb you could try to disconnect everything and drive RLY-ON directly from Vsb via a resistor maybe.

[joehezzer]

Re: usp440m-42lp psu

In post #14 you said you have 5VCtrl. You should also have 5Vsb.

What comes out of the PFC?

If you have 5Vsb you could try to disconnect everything and drive RLY-ON directly from Vsb via a resistor maybe.

i was looking for the standby point to measure i could only see the 5v control point, i had no voltage from anything

[paulstef]

Re: usp440m-42lp psu

Ok,

1. measure from cathode of D103 to the long heatsink (that's primary ground) . When plugged in you should have immediately 170VDC (for 120VAC input). What's the voltage?

2.
If you can't measure 5Vsb on CN801 but you can measure Vctrl on CN805 I could check how they are linked.

Before turning on the unit through 5Vsb - RLY-ON - VS-ON the only power supply that works is the one with the NCP1203. If you have voltage on the ZD501 and ZD502 this chip works. What's the voltage over these two zener diodes?

An oscilloscope would help.

EDIT: I think the voltage in UK is 230VAC? In this case you should have about 325VDC from cathode of D103 to heatsink

[joehezzer]

Re: usp440m-42lp psu

give me 5

[wills123]

Re: usp440m-42lp psu

ok just had a look at shopjimmy and that is the substitute part have you the same 42" plasma screen !!!!

i think its basically the same mine is branded as a tevion but alot scrrens seem to share those same innards

[joehezzer]

Re: usp440m-42lp psu

D103 reads 01.2 vdc 01.3 vac i am gonna pull diodes and test them and see if they are shot

[joehezzer]

Re: usp440m-42lp psu

i think its basically the same mine is branded as a tevion but alot scrrens seem to share those same innards

i see

[paulstef]

Re: usp440m-42lp psu

Oops, that's not good. I didn't analyze that part of the circuit because mine is working. I'll have a look at it.

Where exactly you say you had 5V?

[paulstef]

Re: usp440m-42lp psu

Do you have a voltage at the output of the bridge rectifier BD101? It's the two outer pins.

[joehezzer]

Re: usp440m-42lp psu

Do you have a voltage at the output of the bridge rectifier BD101? It's the two outer pins.

Very minimal voltage botton pin 01.6 upper pin 01.4 v

[joehezzer]

Re: usp440m-42lp psu

Oops, that's not good. I didn't analyze that part of the circuit because mine is working. I'll have a look at it.

Where exactly you say you had 5V?

its dead all over i found somewhere that the big blue relay could be at fault

[paulstef]

Re: usp440m-42lp psu

If you don't have DC voltage between pin "+" and "-" of the bridge rectifier then it is either faulty or there is no AC coming in.

Measure AC between the two inner pins of the bridge rectifier. If there is none then follow the two traces back.

What's the voltage on TNR 102? The green round component right beside R105 R106?

[paulstef]

Re: usp440m-42lp psu

The blue relay only bridges the two white resistors when you turn on the TV. It limits the inrush current when the two big caps are discharged and you plug the TV in.

Normally AC goes through the two resistors. There should DC on the big caps even when the relay is OFF.

[paulstef]

Re: usp440m-42lp psu

Check the resistors R105 R106. Mine are 20R each. Yours could be different since we have 120VAC here.

[joehezzer]

Re: usp440m-42lp psu

If you don't have DC voltage between pin "+" and "-" of the bridge rectifier then it is either faulty or there is no AC coming in.

Measure AC between the two inner pins of the bridge rectifier. If there is none then follow the two traces back.

What's the voltage on TNR 102? The green round component right beside R105 R106?

voltage on TNR 102 00.3v