Re: AOC tft22w90ps intermittently turns off.
I am going to my friends place to look at it in about an hour and then I can put up some pictures, and check to see if it's the backlight. Is there a trick to get this thing open, my friend might have just missed something, wondering if it has screws hidden under the bezel or stickers covering them. He said the case didn't give at all after he took them all out. I can probably figure it out but it could save me some time. .
Op4500
Member
Last Activity: 04-25-2015, 03:12 PM
Joined: 10-18-2013
Location: Oregon
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AOC tft22w90ps intermittently turns off.
My friend picked up a used AOC tft22w90ps monitor, it worked for about a day, now after a few minutes the screen goes dark, when it turns off the on screen display is also not working. I haven't looked at it yet, any ideas? He said he removed all the screws and couldn't get it open. If it's something easy like bad caps or a burned resistor somewhere I'm going to fix it, otherwise it's not worth it, the monitor was a $13 find at goodwill, it was manufactured around 2008. -
Re: Need help desoldering MOSFETs.
It's a fine pointed tip, I'd rather have a chisel tip but radioshack doesn't have them and it's basically my only option unless I order online....Leave a comment:
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Re: Need help desoldering MOSFETs.
Never heard of the chipquick before, I might give that a try. Going to try a better solder sucker first since I can pick that up locally, I think a high quality soldering station is in order, but I'm pretty broke right now. I'm doing this job for a friend for around $100, it's pretty much just a hobby for me. I do soldering work maybe once a month. Maybe I will invest that cash in some better equipment, right now all the tools I have are cheap junk except for my fluke 179.Last edited by Op4500; 05-24-2014, 03:53 PM.Leave a comment:
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Re: Lanzar Optidrive 400id amplifier going into protect
I got one of those little solder sucker bulbs from radioshack, it doesn't really work. Maybe one of those syringe type ones would be better.Leave a comment:
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Re: Lanzar Optidrive 400id amplifier going into protect
It definitely has some bad FETs, tested 4 so far and 2 were shorted between all 3 pins. I posted a thread in the soldering board about it but I'm having a really hard time getting these MOSFETs out, using a 40w soldering iron and copper braid to remove them. Is there a better technique to do this? I broke the leads off one of them because I pretty much have to heat up each pin one at a time and pry it out very carefully. I have to remove all of them because each bank of 6 is in parallel from what I can tell, they all read as...Last edited by Op4500; 05-24-2014, 01:58 PM.Leave a comment:
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Re: Soldering station or hot air station
I liked weller until I went to home depot to get a more powerful iron. I picked up the weller [URL="http://www.amazon.com/Weller-WPS18MP-High-Performance-Soldering-Iron/dp/B0013U9R1E"]WPS18MP[/URL] which boasted "Fast heating 60w performance" I open the thing up and it has an 18w DC power supply, wtf? So either Weller has invented some kind of magic that turns 18w into 60 or they are fucking liars. Yeah turns out it wasn't magic, it was completely useless for desoldering anything bigger than an 18ga wire,...Leave a comment:
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Need help desoldering MOSFETs.
I'm working on a 4000w amp right now, it has 24 large MOSFETs. Took me several hours just to get 4 of them off. I'm using a 25/40w radioshack soldering iron and copper braid to do it. These things are basically giant heatsinks so the solder hardens the second I remove my iron. They all have 3 pins going through the board with a lot of solder on the back. My current method has been to heat up each joint and pull it up with needle nose pliers, then clean up with the desoldering braid. Already broke one of them this way and it very time consuming, is there a better method? I'm doing this at 40w,... -
Lanzar Optidrive 400id amplifier going into protect
I'm going to work on a busted amplifier for a friend, it's a Lanzar optidrive 4001D, protect lights up and it sends a low frequency on/off pulse to the subwoofer and that's all it does. I haven't tested it yet, but I'm wondering if anyone has documentation on it. I'm going to start by testing the 24 MOSFETS. The board has no visible burn marks or signs of stress, capacitors all appear normal and aren't a brand I typically see fail. I'm told this amp is only a year old and he said it's 4000w RMS. This thing is beefy as hell, never worked on anything with such a ridiculous bank of filter caps, it...Last edited by Op4500; 05-10-2014, 02:27 AM. -
Re: Samsung LE32R88BD/ BN44-00155A
When removed from the board CM808 reads 22nF. Any idea what might be causing the low voltage?Leave a comment:
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Re: Samsung LE32R88BD/ BN44-00155A
The main cap reads 132v with the TV off, when I hit the power button it goes to 375v then quickly drops off and settles at 152v over about 10 seconds.Leave a comment:
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Re: Samsung LE32R88BD/ BN44-00155A
I will pull it off the board and test it again, pretty sure I'm reading it correctly, my multimeter is auto ranging and displays the result in nF or uF depending on the range.Leave a comment:
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Re: Samsung LE32R88BD/ BN44-00155A
[url]http://imgur.com/YxUzPWu[/url]Re: Samsung LE32R88BD/ BN44-00155A<b.../YxUzPWu[/url]Leave a comment:
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Re: Samsung LE32R88BD/ BN44-00155A
CM808 reads 150nF, that is an unusual looking capacitor, what is that type called and what does it do?Leave a comment:
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Re: Samsung LE32R88BD/ BN44-00155A
RM801 is a .22ohm 1w fusible resistor. Inverter is getting 1-1.2v on the 24vdc pins. Also the transformer whines when I plug it in it's a pulsating high pitch squeal, most people can't hear it.Last edited by Op4500; 02-06-2014, 09:48 PM.Leave a comment:
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Re: Samsung LE32R88BD/ BN44-00155A
I replaced most of the electrolytic capacitors, as well as a 220pf disc capacitor that had a lead blown off next to RM801, scraped off all the glue and replaced RM801 and the TV still isn't working. I plug it in and the red LED comes on, the light below the screen blinks once, then when I hit power I get one solid beep for about 5 seconds, the white light blinks again and it shuts off. No backlight or sound other than the beep, unplugging the backlight inverter shows no change.Leave a comment:
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Re: Samsung LE32R88BD/ BN44-00155A
I am working on a TV for a friend that has the same problem as OP, I ordered replacements for all the electrolytic capacitors and a new .22ohm 1W resistor. I am going to scrape off all the brown gunk and see if it works when I replace the parts, just wanted to add my photos and see if anyone had information to add, there is a lot of heat damage, I'm concerned that some of the mosfets might be bad as well, When the TV is turned on standby light blinks repeatedly, no backlight or sound. RM801 is obviously blown, even left a nice scorch mark on TVs...Last edited by Op4500; 01-31-2014, 09:04 PM.Leave a comment:
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
I took all my secondary voltage readings with the negative probe on one of the power supply screws, while it was screwed into the chassis. For primary readings I had it on the neutral wire where the AC power comes in.Last edited by Op4500; 11-11-2013, 06:52 PM.Leave a comment:
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
Can't seem to find the problem, I've checked almost everything on that board, any ideas? The only places I get power are the 169VDC at the inverter board and 62VAC at each secondary pin of the power transformer.Leave a comment:
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Re: Need help troubleshooting a sylvania LC420SS8 power supply
Yeah, when I first took those voltage readings everything was connected and screwed in, I did a few checks with each board disconnected from the MPS with no change. The only sign of life I get from this set is a click of a relay when I plug it in and there is a slight high pitched whine from the transformer.Leave a comment:
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