view sonic vx2035wm flashing blue power lite dark svreen

[PlainBill]

Re: view sonic vx2035wm flashing blue power lite dark svreen

Let me think about it but I may just give up on for now. You were very helpfull and I wouldn't have goten this far without your help.

One other thing I noticed that even with the voltages stable I was never able to bring up the menu and when I turn on the monitor without the analog cable connected I get a message on the screen that states no signal analoge cable disconnected then it goes away.

That is normal for most monitors - without a signal you are unable to access the menu.

PlainBill

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

Let me think about it but I may just give up on for now. You were very helpfull and I wouldn't have goten this far without your help.

One other thing I noticed that even with the voltages stable I was never able to bring up the menu and when I turn on the monitor without the analog cable connected I get a message on the screen that states no signal analoge cable disconnected then it goes away.

[retiredcaps]

Re: view sonic vx2035wm flashing blue power lite dark svreen

I got a better pic for you

1) Okay, that new picture helps. Unfortunately, I don't spot anything obvious that is wrong.

2) My best guess right now is that something is wrong on the main board if the analog and DVI signal cause the voltages to fluctuate. Since you say the voltages are stable when there is no connection, it sounds like the main graphics chip might be shorted internally?

3) A really long shot would be to recap the entire main board?

4) I'm out of ideas for now.

[retiredcaps]

Re: view sonic vx2035wm flashing blue power lite dark svreen

D810
.214
.909
.214
.909

D812
.220
lnf
.219
inf

I'm not an electronics expert but I would expect to see the same readings on both. I would expect to see inf on the reverse readings so maybe D810 has a problem.

I forgot to point out that sometimes in circuit readings are not 100% accurate and you have to desolder the component to get an accurate reading.

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

I got a better pic for you

[retiredcaps]

Re: view sonic vx2035wm flashing blue power lite dark svreen

is the main board the power board the one we have been working on?

Main board has the hdmi, rca connections. The 2 previous photos you have are not clear enough to make details (all fuzzy). It should be like this clear so we can make out all the detail and suggest test points.

https://www.badcaps.net/forum/attach...0&d=1290283049

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

is the main board the power board the one we have been working on?

[retiredcaps]

Re: view sonic vx2035wm flashing blue power lite dark svreen

16.4 volts across c809
16.4 volts on I801 pin 4 and 6

Those readings indicate that the SMPS IC is working fine as per page 5 of

http://pdf1.alldatasheet.com/datashe...C2/LD7575.html

Can you post a clear focused picture of the main board (front and back) as close to 2000x2000. Use macro mode if your camera has one.

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

16.4 volts across c809
16.4 volts on I801 pin 4 and 6

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

same symtoms

[retiredcaps]

Re: view sonic vx2035wm flashing blue power lite dark svreen

analog computer cable

What happens if you use the DVI cable instead?

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

analog computer cable

[retiredcaps]

Re: view sonic vx2035wm flashing blue power lite dark svreen

I wasn't able to get the voltage reading since I have to get them off the bottom of the card and I cann;t get to the test points with the cables connected.

I use cardboard for separation and to make sure the board doesn't short out. This allows you to test boards upside down and get the voltage measurements.

the readings for I801 g to pin 6 is .417m

D810
.214
.909
.214
.909

D812
.220
lnf
.219
inf

I'm not an electronics expert but I would expect to see the same readings on both. I would expect to see inf on the reverse readings so maybe D810 has a problem.

All those readings indicate the diodes are good. A diode allows current flow in one direction so it should measure between 0.2 and 0.5V one way and infinite in the other. 0.909V is "close enough" in this case to infinity.

If a diode read the same in either direction, it is shorted.

Did I mention that when the signal cable is disconnected the voltages settle in and the blue flashing lite goes solid orange.

Not that I remember.

Which one do you call the signal cable?

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

You were corect I did have P801 connecters reversed

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

I wasn't able to get the voltage reading since I have to get them off the bottom of the card and I cann;t get to the test points with the cables connected.

the readings for I801 g to pin 6 is .417m

D810
.214
.909
.214
.909

D812
.220
lnf
.219
inf

I'm not an electronics expert but I would expect to see the same readings on both. I would expect to see inf on the reverse readings so maybe D810 has a problem.

I did the reading using the center pin and going to the outside pins. I hope that was the correct way to measure the dioads.

Did I mention that when the signal cable is disconnected the voltages settle in and the blue flashing lite goes solid orange.

All my soder points are fine and making good connections.

[retiredcaps]

Re: view sonic vx2035wm flashing blue power lite dark svreen

I found a bad conection at the soder joint of c825 + side and the soder trace to L808.

That would explain some of the fluctuating voltages on pins 4-9 (as per schematic - your pin numbering might be backwards). Pin 1 is stable at 15.5V DC.

That is why I suggested #5 to doublecheck all your solder work especially in this area around D812, C823, C825, C822, and R833.

Some of things I'm asking you to check is more for verification. I have an idea what to expect for #1 to #4, but it is nice to have confirmation.

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

thanks, I'll work on tomorrow and report back

[retiredcaps]

Re: view sonic vx2035wm flashing blue power lite dark svreen

Refer to the schematic.

1) With power off and lcd unplugged, test diodes D810 and D812 using the diode test function on your multimeter. Report your diode measurements. You should have 4 readings per diode.

2) With power off and lcd unplugged, measure the resistance between pin 6 (Vcc) and pin 4 (GND) on I801. Report your ohm measurement.

3) With power on and lcd turned on, measure the DC voltage across C809 (10uF 50V). Report measurement.

4) With power on and lcd turned on, measure the DC voltage on pin 6 (Vcc) using pin 4 (GND) as ground on I801. Report measurement.

5) Check all your soldering work for solder bridges and gently tugging on all caps to see if they are held in solid.

[Jwh8000]

Re: view sonic vx2035wm flashing blue power lite dark svreen

I replaced the two caps and fixed the loose connection on c825 and I still have the same problem. Any ideas

[retiredcaps]

Re: view sonic vx2035wm flashing blue power lite dark svreen

I'm thinking this is my source of fluxuating voltage.

It could be, but all your voltages are fluctuating expect pin 9.