compaq presario f700 power problem

[alihomee]

i have a presario f700.first time when it came with a power fault.then i change the ic isl6236 at the down corner of mobo.after that it was ok but doest detacting hdd because i replace isl6236 with 6237. so again i unpack it and after that again replace with orignal number 6236.so now the mobo wouldt turns on but the blue led on dc jeck still on . now i am confused how and where should i check for problem.the ic which i replaced is ok and perfectly solded.please need some feedback

[are-red]

Re: compaq presario f700 power problem

Hmmm...replace with new correct code

[alihomee]

Re: compaq presario f700 power problem

Hmmm...replace with new correct code

i already doen this but still no responce.aactually voltages are not comeing to ic i mean no vin.i think something is shorted but i cant find it

[Francisco.s]

Re: compaq presario f700 power problem

i have a presario f700.first time when it came with a power fault.then i change the ic isl6236 at the down corner of mobo.after that it was ok but doest detacting hdd because i replace isl6236 with 6237. so again i unpack it and after that again replace with orignal number 6236.so now the mobo wouldt turns on but the blue led on dc jeck still on . now i am confused how and where should i check for problem.the ic which i replaced is ok and perfectly solded.please need some feedback

I have a presario c700 schematic diagram, but it has not the ISL6236. Have you got the rigth schematic?

[fddizon]

Re: compaq presario f700 power problem

schematic.... f700

[Francisco.s]

Re: compaq presario f700 power problem

i have a presario f700.first time when it came with a power fault.then i change the ic isl6236 at the down corner of mobo.after that it was ok but doest detacting hdd because i replace isl6236 with 6237. so again i unpack it and after that again replace with orignal number 6236.so now the mobo wouldt turns on but the blue led on dc jeck still on . now i am confused how and where should i check for problem.the ic which i replaced is ok and perfectly solded.please need some feedback

The ic ISL6236 generates 5VPCU and 3VPCU, also +12V_ALWP.
Are these voltages ok?

[fddizon]

Re: compaq presario f700 power problem

The ic ISL6236 generates 5VPCU and 3VPCU, also +12V_ALWP.
Are these voltages ok?

i dont think those voltages are present since there is no vin voltage present

i already doen this but still no responce.aactually voltages are not comeing to ic i mean no vin.i think something is shorted but i cant find it

[Tuomo]

Re: compaq presario f700 power problem

i already doen this but still no responce.aactually voltages are not comeing to ic i mean no vin.i think something is shorted but i cant find it

Try measure PL4 voltage and PQ30.

Step by step find where voltages disappears and then measure resistance.

[Francisco.s]

Re: compaq presario f700 power problem

Check also ACOK# signal, (must be low level) and VH28. ACIN signal should be near 2 volts. PU5 also could fail. All the circuit is very difficult to follow and has many components that are likely to fail. Check voltages and post results.
Good luck.

[are-red]

Re: compaq presario f700 power problem

Could be mosfet problem arounf isl6236

[alihomee]

Re: compaq presario f700 power problem

i have also no voltages at isl6236 but on 8724e voltages present.

[alihomee]

Re: compaq presario f700 power problem

on pl4 voltage ok but on pq30 voltages are present onl on one sode

[Tuomo]

Re: compaq presario f700 power problem

on pl4 voltage ok but on pq30 voltages are present onl on one sode

Measure all pins of PQ30 and then measure resistance to ground.

Before measure resistance remove AC Power and Battery.

[are-red]

Re: compaq presario f700 power problem

You said earlier u replace with isl6237 your board running,but not detect hdd?

[Francisco.s]

Re: compaq presario f700 power problem

on pl4 voltage ok but on pq30 voltages are present onl on one sode

Voltages on pq30 should be present as long as you have VA1, and MAX8724 (and surrounding circuits) are ok. (very important VH28, ACOK#, and ACIN voltages)

[alihomee]

Re: compaq presario f700 power problem

around max8724 voltages ok but not present at isl6236

[alihomee]

Re: compaq presario f700 power problem

You said earlier u replace with isl6237 your board running,but not detect hdd?

yes that time notebook is on i mean power and display is ok but only not detacting hdd so i change with right code isl6236 and after that no power

[Francisco.s]

Re: compaq presario f700 power problem

around max8724 voltages ok but not present at isl6236

ISL6236, takes current from VIN through PR180, and this could be open or with hight resistance.

[fddizon]

Re: compaq presario f700 power problem

alihomee,

did you successfully repaired the unit?

please let us know how did it go?

thanks

[alihomee]

Re: compaq presario f700 power problem

not yet i have two units with same problem. i think that fddizon is interested in this.so can u tell me how to check properly and step by step all components