Re: HP w1858 - No Power

Hello again. Sorry for the delay. I take back my last comments on the diode as well. Checked it again and it seems alright. Any other suggestions of what to check? Thanks!

Re: HP w1858 - No Power

The D900 appears to be open. I get no readings from it running in either direction. Work is busy but I'll try to pull the diode out soon and get some more pictures uploaded. Thanks again, more to come.

Re: HP w1858 - No Power

Ran some of the tests you suggested. The startup cap is running at about 14V cold. I didn't notice any difference after heating it up. The resistor tested at 1.4 ohms. Interestingly enough, the D900 diode seems to be shot. Not sure if that's the only problem, but I'm pretty sure I should be getting something through it. Thanks for the help so far. I really appreciate it!

Re: HP w1858 - No Power

The main filter cap showed about 137V plugged in.

Re: HP w1858 - No Power

Aside from the black soot on the corner, was there something specifically that you saw on the transformer showing it needed to be resoldered? The black seemed to be external to the protective tape and could be rubbed off. This is a learning experience for me, so I'm curious why you specifically pointed out the transformer.

Without obviously distorted caps or other clearly damaged parts I am at a loss. I'm wondering what the general train of thought is or if there is a mental checklist to go through to check specific components in a case like...

I have a HP w1858 monitor that I got used when I was back in the states. It had some occasional power issues where the screen would become totally unresponsive after going into power-saving mode. It would have to disconnected from the PC and reconnected to respond again. While unresponsive the monitor would not turn on at all, no lights, nothing. I didn't have time to mess with it at the time, so it was set aside.

I recently came upon a little free time and thought I would check the monitor out again. This time, however, it is totally unresponsive from the start. I tried multiple...

Re: New Members - please post your introductions here

Hi everyone. Currently in Japan. Enjoy tinkering with electronics and came across this site. What a great resource!