HannsG HW173D dead. Recap = new fault.

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

Is the reading suppose to be constant, or does it keep changing and then go to 0V?

[retiredcaps]

Re: HannsG HW173D dead. Recap = new fault.

Is the reading suppose to be constant, or does it keep changing and then go to 0V?

It should be constant.

Let's make sure your multimeter is working correctly.

1) If you put it on 200 ohms and touch the red and black probe together, what do you get?

2) Now put it on 20V DC and measure a new AA cell (battery). What do you get?

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

1) .0

2) AAA is 1.5

[retiredcaps]

Re: HannsG HW173D dead. Recap = new fault.

Looks like your multimeter is working correctly.

Try measuring the voltage regulators again and see if they DC V is fluctuating or not.

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

I placed the boards back into the monitor and connected everything. Each regulator pin reads a constant 0.0V.

[Scenic]

Re: HannsG HW173D dead. Recap = new fault.

hm... do you get any output from the powersupply..?
if so, those voltage regulators could be shot.. seems strange that both died though.. *scratches head*

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

I check the the solder side of the Inverter Board and I have power on the board. Is there a part on that board that I need to check that feeds the Logic Board?

[Scenic]

Re: HannsG HW173D dead. Recap = new fault.

the output voltages from the inverter/psu board to the lcd controller board.

the voltages supposed to be on that connector are kinda visible on this pic in the first post (below the pins on the bottom left)
https://www.badcaps.net/forum/attach...7&d=1265410253

if those are all there and in spec (mainly the 5V and 12V), the next suspects would be those voltage regulators on the LCD controller board for 1.8 and 3.3V.
if these are dead (no output or too low), the controller chip in the center of that board has no voltage and the whole monitor plays dead, even if the PSU/inverter are working fine..

edit: the voltages might also be printed on the solder side of the inverter/PSU board if you're lucky. would make it a bit easier..

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

After having said that I see that I have no voltage going through to the Logic Board. What can I check now, and do you know where the fuse is located? Thx for all the help.

[Scenic]

Re: HannsG HW173D dead. Recap = new fault.

if the PSU/inverter board looks like the one i've linked in post #28, there are 2 fuses.
the mains fuse F101 (brown-ish cylinder below the ground wire at the mains socket) and F240 (black cube to the right of the pins going to the logic/LCD controller board)

looks like there was a place for another one of those fuses right next to that connector that just has a jumperwire in it..

measure it in diode test mode or low ohms mode. (without mains connected!)
if your multimeter says 0L or something like that it's open/bad

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

I removed the black one (F240) and got a diode reading of .001. When you said "without mains connected" I assumed you mean removing the part.

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

Forget what I said about not getting power to the Logic Board. I was using a ground not associated to the pins connecting the two boards. I saw where there was a ground on one of the pins. One pin said it should be 12v and I have 0. The other pin says 5v and I have a reading of .5. This was a DCV reading. Now what?

[alexanna]

Re: HannsG HW173D dead. Recap = new fault.

I think the reading you are seeing is a 500mv voltage drop on the ground side of the board.
What voltage readings do you get on the other pins using a plated ground screw for your ground?
Your edit changes things so disregard

[alexanna]

Re: HannsG HW173D dead. Recap = new fault.

Need a good pitcure of both top and bottom of Inv./P.S.

[jetadm123]

Re: HannsG HW173D dead. Recap = new fault.

You have two diode packs mounted on the same heatsink. One diode should output 5V and the other 12V. Measure the middle leg of each diode for these voltages. Like alexanna suggested, we need some good focused photos of YOUR boards. Referencing someone else's board photos hinders the troubleshooting process.

[alexanna]

Re: HannsG HW173D dead. Recap = new fault.

In the first post I see a fuse F240 by the connector to the logic board,It would be a good idea to check it if it's not already been done.
Well i mised you post about F240 you might want to check it with an ohmmeter

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

Attached are the pictures of my boards.

I did check the continuity on both fuses and they check out.

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

You have two diode packs mounted on the same heatsink. One diode should output 5V and the other 12V. Measure the middle leg of each diode for these voltages. Like alexanna suggested, we need some good focused photos of YOUR boards. Referencing someone else's board photos hinders the troubleshooting process.

Are the diode's D240 & D260 and are we talking about 5DCV and 12 DCV? If so then I am getting a reading of 0V. Am I corrected by using the ground from the power cord?

I just tried to use a different ground and got one diode to bounce between .4V and .6V and 0 on the 12V diode. When the voltage changes from AC to DC, does the ground change?

[jetadm123]

Re: HannsG HW173D dead. Recap = new fault.

Are the diode's D240 & D260 and are we talking about 5DCV and 12 DCV? If so then I am getting a reading of 0V. Am I corrected by using the ground from the power cord?

I just tried to use a different ground and got one diode to bounce between .4V and .6V and 0 on the 12V diode. When the voltage changes from AC to DC, does the ground change?

I can't see the silkscreen on your photos for D240 and D260. On your third photo, they are the only two devices mounted on the same heatsink above the yellow transformer. You mentioned you read 5V on the connector on one of your previous posts. Well, that 5V should coming from one of those two diodes. Is your meter set to DC volts? Try the 20V setting. Place your ground probe on a mounting screw and place your red probe on the middle leg to measure output voltage.

[slvfox2008]

Re: HannsG HW173D dead. Recap = new fault.

I can't see the silkscreen on your photos for D240 and D260. On your third photo, they are the only two devices mounted on the same heatsink above the yellow transformer. You mentioned you read 5V on the connector on one of your previous posts. Well, that 5V should coming from one of those two diodes. Is your meter set to DC volts? Try the 20V setting. Place your ground probe on a mounting screw and place your red probe on the middle leg to measure output voltage.

I have the boards out of the monitor and using the ground from the power cord on the solder side. Doing this I get nothing. If I find another ground on the board, the reading on the one diode goes up and down. The other one is zero.