HP w20. Total Shutdown. Cannot turn-on immediately.

[newbie1]

Re: HP w20. Total Shutdown. Cannot turn-on immediately.

Oops! Forgot about the fact that you already changed the 47uf cap. Back to the drawing board.

Also, what is the model number of the power board? Li Shin XXXXX

Printed on board - E193430
Sticker on it - e053911142 rev 0.3

[newbie1]

Re: HP w20. Total Shutdown. Cannot turn-on immediately.

Light bulb just went on - darn CCFL. The key must be pin 1. Where is the voltage source?

When you get a chance, I've marked off the area of interest on the bottom of the PC board. At a minimum I would like the pins of IC102 identified.

PlainBill

Update
Using my new DMM (beeper mode), i have traced the voltage source of Pin 1 of IC102 to be linked to the Emitter of Photocoupler (EL817).. I will try to check for voltages on that area & its respective components. Any other things to check?

[newbie1]

Re: HP w20. Total Shutdown. Cannot turn-on immediately.

ok guys,, hopefully this is the last time i am going to update this thread..

I just realized this. That the monitor, when plugged to Main Power, will be automatically start-up without me having to pressed the Power switch. Because i did remember switching it off (power switch) the last time i packed it up before continuing it again to troubleshoot just now.

Anyway, further tracing using the DMM, shows that IC103 (emitter pin) is also linked to Pin 1 of IC102. See attached. I continued to measure the voltage on the pins of both the photocoupler with respect to the -ve pin of the big cap. I measure it during stable on & when on standby (power plugged but monitor is not responding to Power switch - No Power LED on).

[IC pin> Stable On > Standby (coma)]

IC105
Pin 1 (Anode)> 121V > 121V
Pin 2 (Cathode)> 121V > 121V
Pin 3 (Emitter)> 0V > 0.72V
Pin 4 (Collector)> 16.5 > 13V (slowly decreasing)

IC103
Pin 1 (Anode)> 121V > 121V
Pin 2 (Cathode)> 121V > 118V
Pin 3 (Emitter)> 6.4V > 0.72V
Pin 4 (Collector)> 16.7 > 13.6V (slowly decreasing)

I thought it is strange that the Pin 3 of IC105 is having different voltage comparing with IC103. So i decided to swapped the 2 photocouplers.
Now when i first plugged to Main power, the monitor did not auto-start as it previously did. Power led is off. When I measure the voltage again, Pin 1 of IC102 is receiving 5.8V & Pin 3 (Emitter) of IC103 is now 6.63V... .. But Pin 3 (Emitter) of IC105 is still 0V at standby.

I pressed the power switch, it light up & monitor is working as normal. I pressed it off and on again & it RESPONDED. Now i am leaving it plugged to the main Power overnight. Let's hope tomorrow it will wake-up when i pressed the Power switch,..

If it does wake-up, my DEEPEST APPRECIATION & GRATITUDE to those who contribute to this thread.. especially jetadm123 & PlainBill .. thanks for all the patience & guidance rendered in helping me to solve this from 9000+ MILES away.. .. .. Even though, I could not find the source of the problem but hope this thead will be useful for those with similar problem as well..

If not, then you will be hearing me again in the next few days.. ..

[jetadm123]

Re: HP w20. Total Shutdown. Cannot turn-on immediately.

Since all you did was swap the photocouplers with each other and now have a working monitor, then the problem may have been a bad solder joint, which this model monitor seems to have a problem with.

[newbie1]

Re: HP w20. Total Shutdown. Cannot turn-on immediately.

Since all you did was swap the photocouplers with each other and now have a working monitor, then the problem may have been a bad solder joint, which this model monitor seems to have a problem with.

jet, i think you are right...
Just to update, so far it is working (stable). I am typing this using it and it no longer shutting down/coma. It is also responding to the power switch well. Just that there are a few scratches here and there..
Anyway, thanks for helping me out, dude....

[shovenose]

Re: HP w20. Total Shutdown. Cannot turn-on immediately.

gonna sell or keep?
great job fixing it and have fun with it n

[newbie1]

Re: HP w20. Total Shutdown. Cannot turn-on immediately.

thanks man.. i think its gonna stay with my boys for long while.. their gaming time is much much longer than i took trouble shooting this.. not to mention each of them wanting their own terminals.. kids nowadays.. spending lesser time at playground, football, soccer, basketball,etc.. Sigh!..