HP Compaq 7620s 7 flashes of death.

[mattbrad2]

Re: HP Compaq 7620s 7 flashes of death.

that's actually good thinking. It could very well be a short coming from the GPU / Northridge. I've had a ton of these. If you have the equipment to remove the chip, you'll get your answer.

[ElectT]

Re: HP Compaq 7620s 7 flashes of death.

This one has been on the shelf for a while now and thought i'd have another look. These motherboards seem to be plagued with this 7 flash then off problem. There are tons of dead ones on ebay...

I did a bit of digging tonight and found a polish tech forum mentioning the model and fault in question.

http://translate.googleusercontent.c...b2N71W9ZEl-BNQ

What i cant fathom from the translation is, is the TPS51120 IC knackered or are they saying there is a short causing the TPS51120 to trip its protection?

It gets too hot to touch with the battery inserted and power off
Same with just power lead and battery and just power lead.
It does however charge the battery ok.



This appears to be the schematic for the area.

http://pdf1.alldatasheet.com/datashe.../TPS51120.html

Im hoping someone more savvy than me can look through their findings and decipher the cure.

Cheers.

Hi, Don't know if you already fix that issue.
I'm working on a case like yours but started because a liquid damage.
I first check all internal PSUs and almost all were shut down. The only thing that the laptop do is charge the battery and light the blue LED when the D/C is plugged and then holds the orange LED and shuts down keeping charging the battery. Not even the FAN start.
With only the battery plugged, the same except the orange blinks 7 times (I suppose its an error code or just the battery "saying" that needs charge).

Well, until now I have replace a resistor but due to the liquid oxidation and the TPS51120. Now here I got the start of the fix. I open the PAD503 and take of the ADP3208(CPU controller) then I measure the resistance of the Q33, voila one short... Next the Q34 and Q35 not shorted but gate and protection diode common issues, if connected they got shorted.

Well, at this moment I'm replacing the parts but seams that's all.
The TPS51120 its the I/O PSU so obvious the laptop won't boot until the PSUs are all checked.

I'll update if something new...
----------
P.S.: Forgot about C647 near CPU skt. Shorted too.

Best Regards,
FSimões

[JonnyS]

Re: HP Compaq 7620s 7 flashes of death.

Hi i have the same issue on not liquided board i try many options but no success

voltage on
L533 - 5,1V
L521 - 3,4V
L527 - 1V
L3 - 1,3V

L503 AND L504 NO VOLTAGE

I DONT HAVE IDEA WHAT IT CAN BE ( SO PLEASE ADVISE ME IF SOMEBODY HAVE IDEA