COMPAQ CQ62 DCin Questions Help!!!

[NConstantinou]

on the slot1 (DCIN) there are 7 wires.
on this slot dcin measures 5v on first fuses(2) instead of 19.5v.why is this!
foxconn_safina_pm_a_hpc_s_mv_mb_v1_rev_mv.pdf
on first mosfet i also get 5v instead of 19.5v.
please explain

Thanks

[NConstantinou]

Re: COMPAQ CQ62 DCin Questions Help!!!

Note: the 2 fuses on schematic are shown that are connected to dcin 19.5v but when i checked slot1 are connected to pins 6,7 which are 5v. pins 1,2 should be 19.5v correct!

[khaahk]

Re: COMPAQ CQ62 DCin Questions Help!!!

What fuses? DC in should be 19V
Bad adapter, bad dcin jack, short on input(maybe pulsing input that reads 5V on multimeter)

[NConstantinou]

Re: COMPAQ CQ62 DCin Questions Help!!!

I do not have DCIN short to ground.
the question i have, on schematic diagram shows slot1 DC Jack, pins 1 and 2 are connected (red and blue wire) to DB8 and then to FBB12 and FBB13 and suppost to be 19v.
when i measure slot1 with multimeter on pin 1 and 2 measures 5v and pin 6 and 7 that goes to FET PQ13 and 14 measure 15v.
it looks like someone switched over pin1 to pin6 and pin2 to pin7 but nobody did!

[khaahk]

Re: COMPAQ CQ62 DCin Questions Help!!!

If you have 15V on 3V rail then most likely you have upper mosfet failure on 3V buck converter. Measure resistance to GND on PR157, PL11, measure PQ34 for short D1-S1 or resistance between PR157-PL11.
If dcin cable unconnected - 19V present on pin 1&2?

[Techtiger]

Re: COMPAQ CQ62 DCin Questions Help!!!

I do not have DCIN short to ground.
the question i have, on schematic diagram shows slot1 DC Jack, pins 1 and 2 are connected (red and blue wire) to DB8 and then to FBB12 and FBB13 and suppost to be 19v.
when i measure slot1 with multimeter on pin 1 and 2 measures 5v and pin 6 and 7 that goes to FET PQ13 and 14 measure 15v.
it looks like someone switched over pin1 to pin6 and pin2 to pin7 but nobody did!

For pin 6 & 7 RH6 RH7 test both side voltage and for the pin 1 & 2 should be 19+ are you using an original adapter test the voltage of the adapter outside of MOB
test the Diode and the 2 caps connected to pin 1 & 2 for any short & PQ36

[NConstantinou]

Re: COMPAQ CQ62 DCin Questions Help!!!

If you have 15V on 3V rail then most likely you have upper mosfet failure on 3V buck converter. Measure resistance to GND on PR157, PL11, measure PQ34 for short D1-S1 or resistance between PR157-PL11.
If dcin cable unconnected - 19V present on pin 1&2?

sorry for the late reply but i was busy with something else.
PR157 resistance to ground 9 mohms and fluctuates. but if i test again i get .6Mohms
PL11 resistance to grn 1kohms
PQ34 D1 S1 .49
resistance between PR157 to PL11 4.7Mohms
what do you mean 19v present on pin 1&2 where!

Thanks for your help

[ferah831208]

Re: COMPAQ CQ62 DCin Questions Help!!!

when u say from pr157 to ground is 9 mohms u mean miliohms or Mega ohms,and then 0.6 Mohms is Megaohms??i personaly don't work with inpedance for this measurements,it's better in diode to find the short circuits, if u messure in diode with red in ground to pr157 what's the value, and anyway ig u have 15v in pins6 7 in slot 1 measure in pl11 out to see if 3.3 v line is high, 'cause if u have 15v mantained in the mb in this line probably many things will be burned, superI/O, LAN IC, Chipset, etc

[NConstantinou]

Re: COMPAQ CQ62 DCin Questions Help!!!

when u say from pr157 to ground is 9 mohms u mean miliohms or Mega ohms,and then 0.6 Mohms is Megaohms??i personaly don't work with inpedance for this measurements,it's better in diode to find the short circuits, if u messure in diode with red in ground to pr157 what's the value, and anyway ig u have 15v in pins6 7 in slot 1 measure in pl11 out to see if 3.3 v line is high, 'cause if u have 15v mantained in the mb in this line probably many things will be burned, superI/O, LAN IC, Chipset, etc

the values are in mega ohms.
when you mention diode mode you mean continuity o diode.
on PR157 when meter in in diode mode i get .455v
why the red lead of multimeter to be in grnd!
using adaptor
on Pl11 30 minutes ago i was getting 1.5v
and and when using power supply i get 3.3v strange!
using adaptor on pin 8 on bios is 1.6v and with power supply 3.3v
19v power rail with adaptor is 3.3-3.4v
using power supply i have 18v BUT IS FLUCTUATING.
the amperage on power supply is set to 0.22A and i get 0.01A reading

pls advice

[NConstantinou]

Re: COMPAQ CQ62 DCin Questions Help!!!

the values are in mega ohms.
when you mention diode mode you mean continuity o diode.
on PR157 when meter in in diode mode i get .455v
why the red lead of multimeter to be in grnd!
using adaptor
on Pl11 30 minutes ago i was getting 1.5v
and and when using power supply i get 3.3v strange!
using adaptor on pin 8 on bios is 1.6v and with power supply 3.3v
19v power rail with adaptor is 3.3-3.4v
using power supply i have 18v BUT is FLUCTUATING
the amperage on power supply is set to 0.22A and i get 0.01A reading

pls advice

[ferah831208]

Re: COMPAQ CQ62 DCin Questions Help!!!

the red in ground multimeter is only a reference of pn union i use for example if u want to check if an IC is low in the Vcc pin, and u messure this way, generally inside have a zener diode or sinilqr circuit for OV Protection, so u can check if the resfing is like a normal diode it's not out of parameters, if for example it reads 120 or so even if it's not shorted to ground it might be damaged, anyway it's only a method i use and normally it's easier for me to gind shir circuits in mbs,but again is only a reference. Now what's happening it's really weird, the mobo is not overconsuming from 19v line, but it u put the adaptor it goes down,u checked the charge IC???max8731, in the past many times i found faulty ones, u can do something,only for testing u can byoass the 2 FETs pq36 pq38 and use the adaptor not the power supply and check if the voltage continues to drop, if it doesn't u have to check ac_ofg signal comes from it8502 check ac detect sectionnof max8731

[NConstantinou]

Re: COMPAQ CQ62 DCin Questions Help!!!

hi

i am trying to remove 8730 ic using flux with hot air but ic can't be removed.
i have not seen such a case so far.
I TRIED 3-4 TIMES BUT NITHING
i preheated motherboard for 20 seconds and then move down to ic.
i tried to add solder to pins of ic,flux again and hot air but nothing.
any suggestions1.
I DO THING JOB FOR LONG TIME AND I NEVER FACE SUCH A SITUATION.

Thanks

[ferah831208]

Re: COMPAQ CQ62 DCin Questions Help!!!

this is an old motherboard,the old models sometimes need higher temperatures it depends even of the soldering station u have, in my experience this motherbord is not like actual mobos that u can burn them if u put the airfow and temperature too high, and also this motherboard dissipate the heat more efficientlythan newer ones,so u'll need longer time to get the chip out

[NConstantinou]

Re: COMPAQ CQ62 DCin Questions Help!!!

Thanks for your comments

[rediii]

Re: COMPAQ CQ62 DCin Questions Help!!!

hi

i am trying to remove 8730 ic using flux with hot air but ic can't be removed.
i have not seen such a case so far.
I TRIED 3-4 TIMES BUT NITHING
i preheated motherboard for 20 seconds and then move down to ic.
i tried to add solder to pins of ic,flux again and hot air but nothing.
any suggestions1.
I DO THING JOB FOR LONG TIME AND I NEVER FACE SUCH A SITUATION.

Thanks

take good old kolophonium/isoprop-flux. go with full air and temp and a big nozzle, parallel to mb and nearest as u can. what kind of smd-station do you use?