Del N5010 not powering up. CK=DC chip burning hot.

[DCJack]

I'm working on an abandoned Dell N5010 that looks to have good power and the power supply sounds good, but when power is triggered the power supply squeals.

I took the board out and powered it on the bench, everything measures good, all FETs pass, but there is one chip that runs burning hot. It is a tiny (probably 4mm x 4mm) with the following markings:

Line1: CK=DC
Line2: H1Q
Line3: .

The third line is obviously a "pin 1" indicator. Plugging the codes into Google gives me nothing useful and I have never come across this chip before.

Anybody know what this little guy is?

[spidey]

Re: Del N5010 not powering up. CK=DC chip burning hot.

it is rt8205. +3v and +5v power ic.

[dycc]

Re: Del N5010 not powering up. CK=DC chip burning hot.

or tps51125

[spidey]

Re: Del N5010 not powering up. CK=DC chip burning hot.

or tps51125

yes it is the replacement for rt8205A not B.

[dycc]

Re: Del N5010 not powering up. CK=DC chip burning hot.

probably have a short on +3v or +5v that is why this chip runs burning hot. desolder coils to find if the short belong to the chip (CK=DK or rt5205 or tps51125).

[dycc]

Re: Del N5010 not powering up. CK=DC chip burning hot.

is there a difference between A and B @spidey

[spidey]

Re: Del N5010 not powering up. CK=DC chip burning hot.

According to datasheets;

pin 18 on A is NC,
pin 18 on B is LG1_CP (Alternative LGATE1 Output for 14V charge pump).
pin 18 on C is SECFB (to monitor the optional external 14V charge pump)

I've never seen "C", btw you can use B instead of A. Sometimes opposite is possible but first you have to check schematic about pin 18.
thats why tps51125 is replacement for B. I was mistaken in my post before it is not A.

[DCJack]

Re: Del N5010 not powering up. CK=DC chip burning hot.

How did you guys find out what the chip was by the little information I provided. I must learn your secrets!

[spleenharvester]

Re: Del N5010 not powering up. CK=DC chip burning hot.

How did you guys find out what the chip was by the little information I provided. I must learn your secrets!

This! I'd love to get into board level repair a lot deeper but I think most people here have some sort of advanced electronics qualifications.

OP if you can't get anywhere you could buy another faulty board and start swapping parts over. It's worked for myself before.

[DCJack]

Re: Del N5010 not powering up. CK=DC chip burning hot.

I am doing some Googl'ing trying to learn how removing the chokes will help me find my short. I feel like I'm missing some basic electronics principle.

[DCJack]

Re: Del N5010 not powering up. CK=DC chip burning hot.

I lifted all the large filter coils (was incorrectly calling them chokes) and the chip(Label 1 in image) is still burning hot, so I removed it. When I applied power back to the board the left most FET(Label 2 in image) became burning hot, so I removed it. Reapplied power to the board and the right most FET(Leble 3 in image) became burning hot to the touch. I replaced all the components I removed but kept the coils lifted and now write this post.

Should I keep going?

[dycc]

Re: Del N5010 not powering up. CK=DC chip burning hot.

after you replaced all the three chips . check if there is always a short between the pin of the two tantalum cap

[dycc]

Re: Del N5010 not powering up. CK=DC chip burning hot.

ptc4603 and ptc4602

[DCJack]

Re: Del N5010 not powering up. CK=DC chip burning hot.

Both of the caps test good out of board but the contact points show continuity to ground.

[dycc]

Re: Del N5010 not powering up. CK=DC chip burning hot.

now you need shematic to resolve this issue. you have to check all components (one by one) bound to those short-circuit . it mean that all the components supplied by 3.3v if the short is on this voltage and the same for 5v if the short is bound to it. tedious process
good luck and you really need it

[DCJack]

Re: Del N5010 not powering up. CK=DC chip burning hot.

Ignore this post, Pin16 is no longer shorting to ground.... I am so confused.

Found something interesting...

When I measure pin 16(VIN) on PU4601 it shows short to ground and Pin8(VREG3) and Pin 17(VREG5) do not show short. How is the chip getting hot if there is no power getting to it because of the ground short at pin16?

P.S. I found the schematic...

[DCJack]

Re: Del N5010 not powering up. CK=DC chip burning hot.

Looking at the schematic I see that PTC4603 has a source voltage from +5_PWR. I can't find anywhere on the schematic where this +5_PWR is being generated. I want to start tracing components from this source.

Another interesting thing... Even though the +3.3v_ALW is shorted as shown by PTC4602, to ground the power button has it's 3.3v trigger.

[whaldsz]

Re: Del N5010 not powering up. CK=DC chip burning hot.

If it is short for both +3.3_ALW and +5_VALW, it's likely that you need to replace PU4601. +5_PWR Comes from +5_ALW.

[prabhucna]

Re: Del N5010 not powering up. CK=DC chip burning hot.

hai hello , how do you say that its rt8205. +3v and +5v power ic.

[prabhucna]

Re: Del N5010 not powering up. CK=DC chip burning hot.

did you got mb circuit diagram