Re: Denon PMA-1560 other channel dead
I've been soldering in new metalfilm resistors to replace carbon ones, wima's for plastic caps and few(most) bad electrolytics have been replaced with Panasonic/Nichicon/NCC. Now I'm wondering about the transistors. I need to replace TR525 which is 2SD2004 but it needs complimentary pair or I need to buy original which is kinda expensive. Any thoughts?
As for the power transistors I've chosen to replace Sanken 2SA1492 + Sanken 2SC3856 with Toshiba 2SA1986+ 2SC5358. Any thoughts on this?
OniJon
Computer Expert
Last Activity: 01-05-2021, 01:25 PM
Joined: 06-29-2012
Location: Helsinki
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Re: Need Help Idnetifying a Component
Resistor networks/arrays I was aware but had to check, thanks. How do I know mica's capacitance/voltage values because my esr meter goes only down to 1uf reliably? I tried to google the text on top of them with no results.
101 should be 100pf but voltage?...Last edited by OniJon; 03-24-2020, 08:11 PM.Leave a comment:
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Re: Need Help Idnetifying a Component
I'll use the same thread for this question...Leave a comment:
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Re: Denon PMA-1560 other channel dead
I've measured most of the carbon resistor in megaohms, so they're definitely goners. Somehow the bias resistor 3DR18R18, ceramic type, is also changed to inductive type frankenstein. Should I just try to get 2 normal non-inductive ceramic type resistors that are over 2W?
I've tried to find something from Farnell (element14) but can't find anything suitable. How about something like this? How accurate this resistors value needs to be?
[url]http://www.ebay.com/itm/153123183757[/url]
[url]http://www.ebay.com/itm/184191408413[/url]...Last edited by OniJon; 03-22-2020, 06:32 AM.Leave a comment:
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Denon PMA-1560 other channel dead
One burnt main transistor, with a blown leg, TR525 blown leg, resistor R551 blown.
I'm a second owner of this amp, somebody "tried" to repair it already. I've removed few carbonfilm resistors because they showed nothing on DMM. Also metallized paper caps went out the window. Total recap is in order of course and I'll change the carbon resistors for something better.
Question is, when I get to it, what are the pre-transistors that affect the sound the most? I've read that these need to be gain matched if it comes to that, how to do that the easy way?
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Re: The Hall of Shame - Badcaps Photo Montage
Bunch of Nichicon HM's from old HP D510S/845G. To my suprise, powersupply was full of HZ and alike, all good....Leave a comment:
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Re: LG22LH2000 TV, Lien Chang AIP-0190 schematics anyone?
I know they are used in many models but I was just curious would it help with longetivity to add more filtering or would extra capacitance hurt something? I'm more than capable at component level changes, fixes and measuring stuff but designing these things is not my strong point. So "what does this do in this circuit" is out of my league a bit....Leave a comment:
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Re: LG22LH2000 TV, Lien Chang AIP-0190 schematics anyone?
Thanks! I ordered glass tube pico fuses at 2A 250V, they should be okay or is the inrush current capability in those 20N series very important? Pin 5 to ground, R108 measured around 0.4 like you said. I also ordered new IC and better caps. Gonna report what happens when I replace all of those.
I don't think it hurts anything to add more filtering like let's say, adding another 25v 1000uf cap to missing point at C202? What about C204, what value would be good and why it's not there? Because I have loads of caps,...Last edited by OniJon; 02-24-2020, 12:54 PM.Leave a comment:
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LG22LH2000 TV, Lien Chang AIP-0190 schematics anyone?
I found this TV from my workplaces electronics waste. I know it's old 2009 model and only hd ready, I just took it out of curiosity and for something little to work on. It has that Lien Chang psu mentioned. On a first look it has one resistor that's exploded, sus'cons that will need replacing juat because they're crap and according to youtube, maybe a power driver ic is in need of a replacement. Pictures are also now up.
IC I'm talking about is strw6252 and blown resistor (or a fuse?) is R111 (dead center in the picture between main filter caps and yellow trafo), which of I have no idea...Last edited by OniJon; 02-24-2020, 06:47 AM. -
Re: BKElectronics XLS200 problem
It's just illusion on the photo, it looks all good in person....Leave a comment:
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BKElectronics XLS200 problem
Hi!
Having weird issues with this subwoofer amp. Once upon a time it buzzed when in standby and no signal coming in, I changed few little caps and this fixed the problem for many years to come. Now this thing started to take huge load of the wall, tripping the breaker and making varying scratchy sounds with no input. I've measured main caps with Peak Atlas ESR70 and they seem to be fine. There is one tiny Nover cap 10uF 50V, it has ESR of 2ohms. Is this normal or should it be lower? Manual of the meter says that 63v 10uf could be as high as 9ohms and still be good but I can't be sure... -
Re: Audio Pro Avantek (B7) subwoofer
Those biggest caps (6800uF) were so dry that when you shake them, they rattle. Never seen that before.Leave a comment:
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Re: Audio Pro Avantek (B7) subwoofer
Here's some images of the amp if anything comes to anybody's mind...Leave a comment:
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Re: Audio Pro Avantek (B7) subwoofer
I got new info about this that could narrow the problem down. If you use power switch manually to power the sub, there is no problems to other devices. Automatic on-off sensing on it interferes with other devices.Leave a comment:
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Audio Pro Avantek (B7) subwoofer
Audio Pro Avantek, B7 plate amp huge power draw on startup. It creates interference to my friends tv, pre-amp and lights. The symptoms are presumably age related, since it is 16 year old amp, any advice?
I've measured it here and there (with Fluke 179) but without ESR meter, cannot say anything about the caps other than that Fluke shows that they have capacitance within tolerance. They're G-Luxon's and Jun Fu's, known BS brands. Should I just yolo this and change all the smaller preamp caps and see what happens? -
Re: Samsung P2770HD problem found, but....
Transformer was the culprit on mine too. Changed that and some of the caps from SamYoung to Panasonic, just in case. Thanks!Last edited by OniJon; 02-27-2018, 01:44 AM.Leave a comment:
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Re: Samsung p2770hd problems
Anybody has any ideas what to measure in this piece of Korean junk? I wouldn't want to start a new thread because problem is the same.Leave a comment:
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Re: Samsung p2770hd problems
Necromancing this thread.
Same problem, image stays on for a fraction of a second and goes dark. No image with flashlight is shown either.
Measuring 14.5V pins of the CN1001 give only 13.3V out. Is this normal or a symptom? Any other parts that I could measure?Leave a comment:
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Re: Samsung LE32A558 (P3C) tuner trouble?
Yes, signal strength is as good with those channels as any other. We tested this in my home in the city with aerial and on their home with cable connection. In both scenarios problem is there. Does anybody know do tuners work somehow differently, use different signal paths or components, when using different bands or is there a possibility that some part doesn't want to work with these lower bandwidths? I'm just throwing ideas because I have no clue what could cause this kind of problem. Is there any way to get firmware update to this thing...Leave a comment:
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Re: Samsung LE32A558 (P3C) tuner trouble?
Signal strength is all good in both cases, with cable or aerial connection. I haven't found any information that they've changed anything in the transmissions so greatly that it would affect older TV's like this. It's weird that it happens in both scenarios and only on those few channels.
It's possible that the problem is on the transmitting end and not on the receiveing end, in this tuner. More weird thing is that even older sets don't have this problem. I've tried to find newer firmware or something but there's none that I can f...Leave a comment:
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