Re: Hanns-G 281D -- No power, Replaced Powerboard
thanks! thats helpful to see it listed like that. i actually have all the caps, just never got around to diving in... too afraid!
tylerwerrin
Member
Last Activity: 01-28-2014, 09:55 PM
Joined: 07-24-2012
Location: Santa Monica
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Re: Hanns-G 281D -- No power, Replaced Powerboard
yep, makes sense. At least the replacement board came free of charge. I posted on the homepage asking for a "re-cap" service, due to my crappy soldering/desoldering on the original board, which I destroyed but didn't get a response.
The solder points are alot smaller than i'm used to dealing with, dangit!Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
Hi guys,
Well I got my new board, and for the last couple days it worked fine but it started getting harder and harder to turn on and now it's not turning on again.
I measured the SB voltage, and it would fluctuate from 4.97V down to 3.9v and then back up to 4.97. I'm guessing this board has the same problem as the other replacement board, as well as the original board. I'm going to try replacing the caps again, this time on board #2 and see what happens.Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
hi retiredcaps,
well, i got ahold of the company in china -- they are gonna send another board out. however, i'm not holding my breath that this one will work any better than the one they sent previously.
In the meantime, i have been searching for the datasheet for my board so I can locate the VCC to track down the starter cap. I haven't had any luck -- an old post about this same board had a data sheet linked here:
[url]http://html.alldatasheet.com/html-pdf/180729/FAIRCHILD/FSDM0265RL/489/1/FSDM0265RL.html[/url]...Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
is it c603, c606 or c707? I had read on the previous mega-post about this same monitor that these three are traditionally the problem children of this board.Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
could you direct me to the startup cap on my pictures? would it be a big one, or a smaller one?Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
When I tried plugging everything in and turning the unit on, I get nothing -- no blue light, no orange light nada. The SB voltage continues to fluctuate from 4.8V down to 3.8V. When I probed the 12V & 24V rails, I got no change in the fluctuation.Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
Thanks for the help with the diagnosis, retiredcaps. I wrote to the company -- we'll see what they say. I still have the other board, which i completely de-capped, however getting it re-capped has proven to be challenging for me. Hopefully I'll get a working replacement board.
One last question, from an engineering standpoint, does the fluctuating 5v SB voltage tell the monitor that it can't turn on because it hasn't met it's 5V requirement? what if the SB had reached 5V, but other voltages were fluctuating? would...Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
I got the new fuse installed -- the voltage at 5VSB now fluctuates in the 4.75 range. It is never stable at any point.Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
sadly they are in china somewhere, so i can't call em up. Their emails are hard enough to understand as it is. In the meantime I will try another fuse and see if it blows. If it holds, I'll test the voltages again and update the thread with what I come back with.Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
Thanks retiredcaps --
Yep, I got an AC plugged in from a working wall socket. I have the plug which connects the powerboard to the AC plug connected to the board (the one circled in green.)
I measured the ohms on the "new" board for the fuse...it reads 9.04 Mohms (M and the ohm symbol, i''m guessing mega ohms, which is a huge number).
I then measured the ohms for the fuse on my "old" board (the one which I tried to re-cap, and kinda messed it up) and got around .4 ohm (which...Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
"Measure a fresh new AA battery. Report your reading."
1.53v
"The 5V SB pin is DC volts. Your red probe should be on that pin. Your black probe should be on the chassis or ground screw. Do not connect any other boards. Just plug in the AC plug."
I probed all the pins. Got nada, although sometimes i can get a flutter in the MV ratings -- it will start at .8~mv or so and then drift down to 0.00v.
"multimeter tutorial vid on youtube"
I watched...Last edited by tylerwerrin; 09-07-2012, 12:31 AM.Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
Hi guys,
I took the readings with my multimeter.
5SB -- 0V
PSON -- 0V
all the 12v -- 0V
all the 24v -- 0V
I tested the power board without any other cables connected but the AC plug. I used several different verified ground points, and no change. All measurements were taken with the AC function on my multi meter, as well as DC (just to make double sure.)
What should I do next? Should I try connecting other cables to the powerboard (like the inverter,...Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
sorry for the crummy photos -- here are some high res ones, which i borrowed from a couple different threads on this site.
In measuring 12v & 24v, does that mean the voltage at the pins will default to 12v and then go to 24v once the power button is pressed? or are there two separate terminals that I should probe, one for 12v and one for 24?...Leave a comment:
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Re: Hanns-G 281D -- No power, Replaced Powerboard
The initial fault was that the monitor became harder and harder to turn on -- sometimes it would turn on right away, other times it would take 20-30 presses of the ON switch to get it to "catch". My friend who gave me the monitor said that it started doing it a year ago, and he just put it in the closet and let it sit.
I could get the monitor to turn on for about 2 weeks, then it got worse and worse, then nothing at all.
Here are some pictures of my powerboard. None of the capacitors are bulging...Leave a comment:
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Hanns-G 281D -- No power, Replaced Powerboard
Hi guys,
I've read a couple Hanns-G threads for this very same monitor (281D) on this site, and I concluded that I had a problem relating to bad capacitors (a common problem for this monitor), where the capacitors dry out, causing a high ESR condition. I couldn't get the monitor to turn on at all, and no "Standby" mode either. It was as if the monitor wasn't plugged in at all/
A fine gent was nice enough to post the needed capacitors to do a full replace of the board (on this forum), and I ordered them from Digikey. However, I was a bit too eager in the...
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