Dead dps-162kp-1 powerboard

[Danny kikkert]

Hi everyone,

I have a dps-162kp-1 runtka932wjqz powerboard wich has no power at all on the cold side.
I replaced ic7903, r7900, R7902, C7901, d7950.
Checked the diodes around the chip and also the caps.
On the ic pin 5 no voltage, pin7-8= 315V
On the T7901 pin 1-4 no voltage, pin 2-3=315V
Anybody have any idea where to look further?

Any help is welcome
Thanks Danny from holland

[Danny kikkert]

Check the resistance of IC7903 pin 4 to 3, if it is not shorted, there may be a possible fault with ic7902 ac brown-out ic you might try removing J7018 near @5 and see if you get any vcc on pin 5 of ic7903, If you look at the datasheet you will see the startup vcc is generated by the ic internally and charges C7907
In post #3 I said to replace C7918, that should have been C7907

and as stated above, they may be fake ic's

Did you mean to remove the @5 on the photo?, pin 4 to 3 is not shorted, the caps 7918 and 7907 are fine I checked them with an esr meter and multimeter.

Greetings dannny

[Diah]

once i faced dead dps-162kp after repairing all parts on primary it remain dead.. then after taking the main transformer outside the circuit i found there are cut between the coil and standing pins.

[R_J]

The A6069H gets the vcc startup voltage on pin5 from an internal startup cell inside the ic, so you either have a short on pin5 or the new ic is bad, also replace C7918
Pin 5 must have at least 15.3vdc for the ic to start

Why did you replace r7900, R7902, C7901, d7950 ? were they bad, as that would give an idea what may have happened

[nomoresonys]

Maybe check out D7907.

[Danny kikkert]

The A6069H gets the vcc startup voltage on pin5 from an internal startup cell inside the ic, so you either have a short on pin5 or the new ic is bad, also replace C7918
Pin 5 must have at least 15.3vdc for the ic to start

Why did you replace r7900, R7902, C7901, d7950 ? were they bad, as that would give an idea what may have happened

The r7900 was blown, R7902 gave bad reading, the C7901 wasn't blown, but replaced (wanted to check out of cirquit, but fell on the ground and lost it some where in my barn) d7950 was shorted. Yesterday I replaced the ic with new one. Nothing changed.

Cap 7918 and D7906 did look fine in circuitry, I Wil remove them and check them later on

Thanks for the reply

[lotas]

The photo shows that the STR-A6069H is not the original (relabeling), but a fake.

[nomoresonys]

Does appear to be a fake, I don't recall that 5 in the real ones, where did you get it?

[R_J]

Check the resistance of IC7903 pin 4 to 3, if it is not shorted, there may be a possible fault with ic7902 ac brown-out ic you might try removing J7018 near @5 and see if you get any vcc on pin 5 of ic7903, If you look at the datasheet you will see the startup vcc is generated by the ic internally and charges C7907
In post #3 I said to replace C7918, that should have been C7907

and as stated above, they may be fake ic's

[Danny kikkert]

Does appear to be a fake, I don't recall that 5 in the real ones, where did you get it?

I don't know it for sure, I thought ebay

[Danny kikkert]

Check the resistance of IC7903 pin 4 to 3, if it is not shorted, there may be a possible fault with ic7902 ac brown-out ic you might try removing J7018 near @5 and see if you get any vcc on pin 5 of ic7903, If you look at the datasheet you will see the startup vcc is generated by the ic internally and charges C7907
In post #3 I said to replace C7918, that should have been C7907

and as stated above, they may be fake ic's

Did you mean to remove the @5 on the photo?, pin 4 to 3 is not shorted, the caps 7918 and 7907 are fine I checked them with an esr meter and multimeter.

Greetings dannny

[Danny kikkert]

I don't know it for sure, I thought ebay

I just ordered new ones, just in case. Now from a shop in Germany.

[Davi.p]

Hi, about what R-J says, that IC7903 has startup current on pin 5, sound strange to me, i have not searched datasheets, based on photos, i see that Pin 5 takes current only from aux winding of transformer, usually those type of chips takes the startup from the primary winding of transformer, after the normal current on pin 5, i suggest Danny to check the original IC7903 for short on pins 1,8, if there is, check the R7907, the pink one near the big PFC inductor, it must be opened.. replace it and test the board, preferably with lamp in series..

PS: i see no signs of counterfeit, you can use the actual one for me..

[Danny kikkert]

Hi, about what R-J says, that IC7903 has startup current on pin 5, sound strange to me, i have not searched datasheets, based on photos, i see that Pin 5 takes current only from aux winding of transformer, usually those type of chips takes the startup from the primary winding of transformer, after the normal current on pin 5, i suggest Danny to check the original IC7903 for short on pins 1,8, if there is, check the R7907, the pink one near the big PFC inductor, it must be opened.. replace it and test the board, preferably with lamp in series..

PS: i see no signs of counterfeit, you can use the actual one for me..

Thanks, I always test with a lamp in series, I desolderd most components in that area and tested them. They tested fine.

On the transformer I get B+ voltage on pin 2-3, but on pin 1-4 nothing, the trafo also has no shorts.

On the cirquitry of ic 7902 also everything tested fine but also there is no voltage.

Is it possible that the voltage needed for that circuit comes from ic 7801?

[nomoresonys]

Any update on this??

[Danny kikkert]

Any update on this??

Today I received new ic, I'll keep you updated

[Danny kikkert]

so ive installed the new ic7903, nothing! i also noticed a shorted diode D7903.
i gues the transformer is dead

[R_J]

Why would the transformer be dead? did you replace the shorted diode and see if the supply works? D7903 is a 15 volt zener diode NZX15B.

[Davi.p]

Yes,.replace diode and replace completely transformer solder

[Danny kikkert]

Why would the transformer be dead? did you replace the shorted diode and see if the supply works? D7903 is a 15 volt zener diode NZX15B.

idd replaced the diode with ann original.
my electronics knowledge is a little poor so i guess that the te transformer have to deliver some voltage to pin 5 on the chip. but there is none!
or should the cip deliver voltage to the transformer?
on pins 2 and 3 i have normal voltage. on 1-4 none. when icheck with multimeter pins 1 and 4 have continuity.

[Davi.p]

What model of tv we are talking of? Where do you got the chip? Is probably a fake , scrached surface.. try a different source an don't get the cheapest..