Re: Sun / Samsung 24" warmup issues



not sure if you read the whole intervening saga but my first attempt at repair I used standard caps that weren't low ESR. I suspect that was the reason it took a good hour to start working. Took me a couple of weeks to get the parts together then tonight with the proper caps in place the first power on displayed the original problem. Altogether it was plugged in for less than a minute so it definitely didn't get hot.

Came back to take pictures of the problem an hour later and so far it hasn't displayed even...

Re: Sun / Samsung 24" warmup issues

yes.

the issue in question is something I've seen repeatedly even when it was in it's original position on the desk. So far other than that first power on from completely cold this time, I've seen no other hint of any more noise.

guessing my next test is to leave it powered off again for a couple of days and see how it behaves. Not sure -- at the moment it looks perfect....

Re: Sun / Samsung 24" warmup issues

Took a bit to get the right caps ordered -- panasonic FRs worked for the 1000uf 35v, but the FR version of the 2200uf 10v was in danger of hitting the heat shield at 25mm. So I had to go with the FM version there which is only 20mm tall. (to be clear, I didn't order parts that wouldn't fit, just had a hard time finding both the right parts from the same place). The remaining caps I initially replaced met or exceeded the original CapXon specs so I left them alone.

Got it all back together hooked it up to my laptop, and got virtually...

Re: Sun / Samsung 24" warmup issues

Most of the caps on the board are a CapXon series KM. I pulled the data sheet and unless I misunderstand these are just standard 105C rated caps and not low ESR?



There are four CapXon series GL caps, including the first 3 I replaced (1000uf 35v) and a 4th I didn't replace till the second go-round (2200uf 10v).



So here's my what I would replace these with from panasonic, based on the digikey website. Only confusion on my part is that CapXon quotes "impedance" in their spec sheet...

Re: Sun / Samsung 24" warmup issues



Thanks, that would definitely explain the behavior I'm getting. That also makes it sound like the original caps initially failed in a way that they stopped working like low ESR and had higher resistance till they were warm?

Anyway I'm working up a purchase of [I]actual[/I] Low ESR caps to fix 5 of these now. Glad I checked here before I tore into a second monitor.Re: Sun / Samsung 24" warmup issues



Thanks, that would definitely explain the behavior I'm getting. That also makes...

Re: Sun / Samsung 24" warmup issues



okay I was afraid of that after seeing your first post. Parts-Express has a local storefront in addition to the website. That's where I got the low ESR reaction -- their website does claim the parts I bought are suitable for SMPS.

A further search on Mouser reveals the parts I bought are a series that is 105C rated but apparently not low ESR because Lelon has a different series that is low ESR. Sigh.

Strange that the monitor works really well after warm up and in fact even the warm up issues are...

Re: Sun / Samsung 24" warmup issues



Everything I replaced was stamped with a 105C rating -- I asked for Low ESR at one place and got a confused look so just said "High Temp".

I got most of the caps from Parts Express but unfortunately didn't pay that much attention to the brand -- they stock Lelon. I do have one nichicon from a different place because Parts Express had no equivalent.

I started with only the 3 obviously bad ones but then when that didn't work your standard answer is actually what led me to replacing everything...

First thanks in advance for this forum, I've learned a ton in just a few days. One of the most valuable resources I've ever run across on the web -- I didn't have any particular interest in troubleshooting electronics but after what I'm reading here this could be a pretty cool new hobby.

I have 2 of the same monitor as in this thread, from a group buy about 5 years ago. All the ones I'm aware of are having similar issues to what I describe here to varying degrees, a couple of people gave up, another one had his professionally repaired, etc.

[url]https://www.badcaps.net/forum/showthread.php?t=14767[/url]...