HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen.

[sententia]

Hello everyone,

I have this HP mini 2140 Galileo 1.6 which came to me with a melted Q1017.
The laptop would turn on upon pressing power button and turn off.

I replaced now the Q1017 (after almost destroying the pads, however i think all connections are still there) and now as soon as i connect the power adapter it starts (without pressing the power button) flash the red power led 8 times and switches off and start same loop. If battery is connected this happens only 1 time upon pressing the power button.

If i leave the power adapter on the U8 (TPS51124) gets quite hot soon.

Any ideas?

Thank you!

P.S. I tested with only LCD connected if that matters. Also i don't know what or how the laptop was damaged in the first place. Q1017 page 8 of schematic

[dj_ricoh]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

29£

i had a 2133 and i try a bios reflow and after i bough another board from ebay!

if possible don`t waste time

[sententia]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

29£

i had a 2133 and i try a bios reflow and after i bough another board from ebay!

if possible don`t waste time

Do you mean reflash the bios or reflow the cpu?

Also did you have same symptoms, power cycle 8x red led flashes?
I have read your post in the other thread about 2140 while reading for solutions.

I will try a bios reflash just in case, but i think my problem looks power related. I want to spend some time to find a solution and get some experience in the process.

Thanks!

[khaahk]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

Did you exchange q1017 with the exact same model? Resistance from L1015 to gnd?

[sententia]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

Did you exchange q1017 with the exact same model? Resistance from L1015 to gnd?

The part is the same FDMS9620S, allthough i only got part number from schematic as ic was destroyed and could only read FDMS9.

Now resistance from L1015 to gnd is 2,5 Ohms with q1017 on board....

Don't know but it does not look right!

[sententia]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

I have some more input.

I removed Q1017, L1015 and C1063 to take some more measurments.

+ side (1) from C1063 and L1015 (1) have 32ohms resistance to ground.

Side 2 of L1015 has 3ohms resistance to ground.

Does this looks like something is shorted?

Any advice on what to check next?

[sententia]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

Guys anyone some input??

Should i go ahead and order and replace also the TPS51124 which get very hot during power cycle process?

Is it possible that this might be shorted as well?

Thanks!

[sententia]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

I have removed U8 TPS51124 and now side 2 of L1015 has no resistance to ground.

However resistance between C1063 C18 C16 and all capacitors in VCCP line (page 24 of schematic) still have about 30 ohms resistance (actually it varies a bit from 28 to 32 ohms each time i get a reading).

Thanks!

[khaahk]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

Change the TPS51124, good chance that it is bad.

[sententia]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

Change the TPS51124, good chance that it is bad.

Ok i will do that as soon as i receive the part.

But does the resistance on c1063 c18 c16 terminal of about 30ohms sound ok to you?

Thanks for the help!

[sententia]

Re: HP mini 2140 - 8 red led flashes and off and on again. No POST boot. Black screen

Something is definitely shorted in this motherboard except U8 which is now removed ( if that was the shorted part).

Anyway i tried to connect the battery and saw just a bit of smoke but don't know from where it was.

Now if i input 4.2V and high amps Q5 gets extremely hot really fast and after a while the Northbridge U1009 intel 945GSE gets a little hot.

From measurements i see that VCCP line has 30ohms to ground.

But something else must be shorted as well?
Any help?

Thanks!