Re: Dgm l2442wd
My original one of these just failed - caps again.
pillboxhunter
Member
Last Activity: 01-26-2025, 08:27 AM
Joined: 07-26-2014
Location: Newcastle Upon Tyne
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Re: Morduant Short Avant 309i Active Subwoofer
Output transistors replaced - still doesn't work.
Measured voltage on large filter caps as +62 and -62v - stuck now.Leave a comment:
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Re: Morduant Short Avant 309i Active Subwoofer
Going to try some new output transistors pick em up from rs on Tuesday.
Seen other reports of the two caps already replaced being associated with damaged output transistors.Leave a comment:
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Re: Morduant Short Avant 309i Active Subwoofer
Got the replacement 2sc1815 and fitted it. re-assembled sub and it works - for about 2 minutes then back to what it was doing before:-(
Any ideas?Leave a comment:
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Re: Morduant Short Avant 309i Active Subwoofer
It does appear to be a digital amplifier and the caps have arrived and been fitted - but in the process the 2sc1845 screwed to the heatsink and attached to the circuit board by an 8 inch flying lead lost it's legs so waiting for a replacement for that ;-(
I did hear the Sub working at it's previous owners house, a long time ago, and it was (hopefully) not set up properly as it made my head ache with the one note overblown bass.
I examined as much of the board as possible for bad joints and found none.
It will be...Leave a comment:
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Re: Dgm l2442wd
Caps detailed above replaced and monitor now working 100%Leave a comment:
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Dgm l2442wd
Got one of these from Ebay (£10.50).
Power LED comes on, loud buzz from monitor and everything goes off.
Opened it up and found 5 Hermei caps bulged and leaked. Have ordered replacements (panasonic FC series) for all electrolytics on the board - will update when fitted. Bulging caps circled in red in third picture.
Strangely the 450v 120Uf cap was loose although still soldered so I replaced it with one from a dead Samsung power board.
These are (usually) an excellent monitor with a PVA panel and were popular a few years ago as several places were selling them at a... -
Morduant Short Avant 309i Active Subwoofer
Got given the above because it "works sometimes and not others".
Connected it up and it works for a short period then sound breaks up even at low volume.
Opening it up I see lots of brown glue that has gone off and two 10uf 100v bipolar electrolytic caps that have bulged and leaked.
Removing the caps was relatively easy after unscrewing the large aluminium heatsink - refitting looks as though it will be difficult given the proximity of the blue filter cap. surprisingly 10uf NP caps are difficult to find in the UK, HiFi collective turned out to be the most affordable... -
Re: Samsung t240 Totally dead (NOW FIXED)
Monitor fixed with replacement power board. (arrived much faster than expected from China and looked new - no signs of heating on any components or board.)
Old board IC101, FAN7602B has different readings from new board compared to old so will look to replace that and see if old board can be brought back to life to keep as a spare.Leave a comment:
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Re: Samsung t240 Totally dead
If converting one of these to LED backlights would removing F301 disable the inverter but leave the rest of the psu board working?Leave a comment:
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Re: Samsung t240 Totally dead
I've ordered another board so I have something to compare measurements against - won't be here for a couple of weeks though.
Thanks for the help so far
Leave a comment:
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Re: Samsung t240 Totally dead
The browning on the board isn't as dark as it looks in the photo and the tranny doesn't read shorted. It's an AP4506GEH on the board (STU312D on the circuit diag).Leave a comment:
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Re: Samsung t240 Totally dead
I think that's probably what needs doing - I have a friend who works with smds for his job and he's just replied that he can do it - can't get the chip anywhere except Ebay though and not until 18th Aug at the earliest! How likely is it that there isn't further damage?
Might be time to get a replacement board.Leave a comment:
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Re: Samsung t240 Totally dead
Doh! ground pin to pin 6 with power on reads 1.9vLeave a comment:
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Re: Samsung t240 Totally dead
To pin 1 0.93M, Pin 2 62K, pin 31.095K, pin 5 7.71K, Pin 6 3.5K, Pin 7 Open Circuit, Pin 8 reads 0.6V LO Z.
Big brown resistor reads 0.6 OhmLeave a comment:
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Re: Samsung t240 Totally dead
Hi Budm, the number is FAN7602B - I have spare Mosfets if replacement is damaged - fuse doesn't blow so hope it's not. Not sure I'm going to be able to replace that smd chip - don't have a hot air station - although I have a Gas soldering iron with air nozzle so may be able to use that?Leave a comment:
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Samsung t240 Totally dead
Hi, got a Samsung Syncmaster T240 that appears totally dead. When I got it it had a blown fuse F101 3.15A. I replaced it and it immediately blew again and took out the Thermistor TH101 (SCK 056). Further investigation revealed Mosfet Q101 (FQPF 7N65C) was blown. I have replaced the mosfet, all the electolytics and the SCK 056 (with a SCK 057) I also replaced the inverter transformer with a new one from Ebay although the old one reads OK.
Following the above the monitor is still totally dead, not even the power LED lights. Measuring voltages gives no output on any of the pins of CN2 or CN3.... -
Re: New Members - please post your introductions here
Colin Anderson from Newcastle upon Tyne, UK. Some experience of mending and building electronic stuff looking for help with Samsung monitor(s)Leave a comment:
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