HP 1825 Display Black Power Light Green

[printone2]

Re: HP 1825 Display Black Power Light Green

For ground, use a ground screw nearest the connector. Retest and post voltages for pins 1-8.

Your fuse is good if it measures 0.8 ohms.

Pin 1 11.9 (red jacket)
Pin 2 11.9 (all others gray jacket)
Pin 3 11.9
Pin 4 4.6
Pin 5 3.2
Pin 6 0.0
Pin 7 0.0
Pin 8 0.0

[retiredcaps]

Re: HP 1825 Display Black Power Light Green

I have the com lead on the first colored wire, which I thought was ground.

I read .8 at 200 ohms.

For ground, use a ground screw nearest the connector. Retest and post voltages for pins 1-8.

Your fuse is good if it measures 0.8 ohms.

[printone2]

Re: HP 1825 Display Black Power Light Green

I have the com lead on the first colored wire, which I thought was ground. The other wires are all the same color.

I read .8 at 200 ohms. My test leads give different readings if I use a different part of the lead, but the cleanest reading is in the .8 range with the fuse off the board.

[retiredcaps]

Re: HP 1825 Display Black Power Light Green

I see that I have three wires farthest from the fuse have -12v, the next has -8.5v, the fifth has -7.5v and then the sixth and seventh show no voltage and the last wire is ground.

The fuse tested good for continuity.

What are you using for ground on your voltage readings? The readings should all be + DC V.

Continuity can be misleading. On some multimeters, something is continuous if the reading is less than 1800 ohms. I suggest remeasuring the fuse and using just 200 ohms (if manual range). A good fuse should measure less than 1.0 ohms.

[printone2]

Re: HP 1825 Display Black Power Light Green

I see that I have three wires farthest from the fuse have -12v, the next has -8.5v, the fifth has -7.5v and then the sixth and seventh show no voltage and the last wire is ground.

The fuse tested good for continuity.



On the voltage regulator I have 5v on the lead marked "vin" and 2.5v on the center lead. The part # is CHN K310 LT25 Brand seems to be SI. That is the best I can make of the markings on the voltage regulator.

[fuhrer]

Re: HP 1825 Display Black Power Light Green

you can also try testing ze continuity of ze fuse..it's on the left side of the connector cn1 in the inverter board

[jetadm123]

Re: HP 1825 Display Black Power Light Green

In your first photo, try checking the output of the voltage regulator. I believe it's the device right above the bar code label (looks like VIN and GRD? are marked next to it). What's the part number on the device?

[fuhrer]

Re: HP 1825 Display Black Power Light Green

howdy.have you checked all the necessary voltage going to ze inverter?

[printone2]

I have a couple of these HP 1825 (18") monitors that appear to power up (green power light comes on and stays on) but I never see any video with or without a flashlight. There are 13 Capxon caps spread across the power supply and video card. The caps are two different sizes in height 10 mm and 8 mm. The can diameter is 10 mm on all. Looks like I have room for taller cans too.

Here are the markings on the caps:
Capxon 470uf 25v GL 105c c312 vent

I see that Capxon is on the bad list and their site is not available to determine specs of the caps.

None of the caps appear out of shape or leaking. The cards do not appear to have any burn marks on the top side, but I have not turned the PCB over.

The monitor was made in April 2003.

Is there anything I can test at this point or should I assume all the caps are bad before going further?

Can someone make a recommendation on the replacement cap?

The video card is marked Hudson 170b Dual 31381035623

Thanks.