Thanks, I just learned something !
NOTE: I do all my work with old lead solder....
MrCreosote
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Last Activity: 11-13-2024, 07:36 PM
Joined: 12-08-2005
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Replace a TNY255G with a TNY255GN in an APC BE725BB UPS
The UPS appears to be working properly but it is not float charging the battery. It was in service for about a day and then started beeping that battery capacity was low. I removed the battery and it was just over 9v. I connected everything and measured no change in bat voltage so it was not charging.
UPS had worked fine, after years, battery needed replacement. Installed battery and then:
IC blew up with I got a strong arc at the wall outlet when I plugged in - I didn't' realize the unit was switched ON. Possible contributor might be I had an overcharged new 12v battery... -
Re: 2 Belkin KVM switches have dim VGA output
UPDATE:
I found a repair of what appears to be the identical 8-port KVM where they had VGA issues: strong horizontal streaking (mine has some when there is sharp transitions from black to white on a scan line, but not dramatic at all).
He added a blue cap on the PCB where there was a place for one and solved his problem.
[I][B]Mine has that cap![/B][/I]
Here's the link: [url]https://www.instructables.com/Fixing-white-streaking-of-Belkin-omniview-pro2-KVM/#discuss[/url]
...Leave a comment:
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Re: 2 Belkin KVM switches have dim VGA output
Anyone have a chance to look at the PCB's?Leave a comment:
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Re: 2 Belkin KVM switches have dim VGA output
Tried another adapter 12v 2a (instead of 1a specified) - NO CHANGE.
Here are pics of the boards:...Leave a comment:
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Re: 2 Belkin KVM switches have dim VGA output
Will try 2a adapter in next 24 hrs hopefully.Leave a comment:
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2 Belkin KVM switches have dim VGA output
When compared to a direct VGA connection, these 2 switches both output a darker image. The switches are:
4-port Omniview Pro2 f1dz104t
8-port Omniview either f1da108t OR f1dz108t (look and function same, OSD may be only difference.)
The 4 is dimmer, the 8 is massively dimmer - both with same AC adapter and cabling.
[B]AD ADAPTER:[/B]
There were issues with previous AC adapter, it failed during lightning strike that blew up TV and other stuff and tripped a 15 amp breaker in the main panel which also had a whole house Cutler Hammer... -
Re: Bad Caps in the Movies !!!!!!
Those of you who researched the device, did you watch the movie and notice them like me? or just ran with my tip?
Wow, I would say over 50% of XP computers that I've had had them. (I was doing a neural net project and had many running at the same time training.) Power supplies too.
I even contacted Jackon I believe and scolded them for their bad caps and that it would be a nice goodwill gesture to send me replacements. So they sent me bags of 25-50 for 3 or 4 sizes that I encountered bad. All for free....Leave a comment:
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Bad Caps in the Movies !!!!!!
Has anyone ever spotted any?
Around 1:26 in My Mom's New Boyfriend there is a closeup of a board with a 2x3 layout of 6 caps where 4 are clearly swollen and probably all 6.
I'm just wondering if I might be the first person on the planet to see bad caps in the movies. Probably not, it's almost impossible to be the first at anything after the internet.
Anyhow, I was quite excited to notice them - it would be hard not to, the closeup is very! -
Re: Lightning Strike: 55" TV dead: is display panel OK?
TV FIXED: I got the shopjimmy ALL boards kit for $55 shipped. Put the power and main boards in. Fired it up, 3 firmware updates, and it's running just fine.
Now I can wait for 100% ATSC 3.0 adoption and who knows, affordable OLED? (Hisense might try to horn in on the top tier w/cheaper OLEDs - we'll see. But their 100" 4k for $3500 makes me take notice.Leave a comment:
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Re: Lightning Strike: 55" TV dead: is display panel OK?
Yes it is the RSAG7.820.6106/ROH and there is 0V @ the two 12v pins when plugged in. (and 24V @ the two 18v pins).
I will read all pins on the old PSB and then when I put all the replacement boards in, I'll reread them and compare....Leave a comment:
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Re: Lightning Strike: 55" TV dead: is display panel OK?
Well, I got all 4 boards for $45 so I went that route.
I was starting to think the Main was the problem but that 24v threw me off as well as no 5v.
So I guess they made a non-regulated "18v" supply which I suppose is OK if the load is constant but how does one now tell if the voltage is out of spec?
Just wondering: how do you switch on the PSB on the bench?Last edited by MrCreosote; 08-26-2021, 08:45 AM.Leave a comment:
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Re: Lightning Strike: 55" TV dead: is display panel OK?
There is no 5v Standby voltage that powers the main board which switches on the PSB via the SW pin. Also, read threads and the two 12v pins and two 18v pins are the ones that are switched on. When plugged in, there should only be the 5v STB voltage - the 12 and 18v should be off - they energize when set is turned on. So 24v on the 18v pins when set merely plugged in is way bad.
This also means there is no way to switch board on when tested on bench since there is no 5v STB present.
...Leave a comment:
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Re: HiSense 55HtB power supply bench test: weird voltages
Both STB and SW are 0v.
So I've go NO standby power supply and the 18v pins are running 24v.
RIP power supply board.Leave a comment:
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Re: Lightning Strike: 55" TV dead: is display panel OK?
When I got the 24v on the 18v pins, the first thing I did was try another multimeter. I got the 24v w/board tested on bench and also fully installed in the TV. Something is "off" with that board.
I don't know how to "turn it on" on the bench because it does not have a 5v standby voltage, just 2 12v pins in addition to the 2 18v pins. I would test the 12v if I knew how to jumper it "on" on the bench.
I have a pin callout I will edit in here shortly...Leave a comment:
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Re: Lightning Strike: 55" TV dead: is display panel OK?
This sounds like great advice.
Might also explain why the ceiling fan motor is dead too. (could be the little glass thermal overload thingee burried in the windings popped)...Leave a comment:
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Re: Lightning Strike: 55" TV dead: is display panel OK?
I was trying to get a general sense as to the probability that a display is bad.
It is a Hisense 55H7B and here is the kit:
[url]https://www.shopjimmy.com/search.php?search_query=hisense%2055h7b%20complete%20led%20tv%20repair%20parts%20kit[/url]
Obviously if the lightning strike is close enough, every single component in the TV will be destroyed.
I'm guessing although the LED standby is not on, the fact that there is 24v on the PSB 18v pins (#9...Leave a comment:
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Lightning Strike: 55" TV dead: is display panel OK?
[B]THE LIGHTNING:[/B]
[INDENT]This was a very close strike, blew a 15 amp breaker for all ceiling lights in home AND could smell ozone for a few minutes after strike.
Very close and probably a very strong EMP.[/INDENT]
[B]THE TV:[/B]
[INDENT]No standby LED. Some voltage from PSB (not totally dead).
[U]But found a kit of ALL 4 circuit boards for $55.[/U][/INDENT]
At first thought, this will fix my TV.
But then lightning has the ability to totally fry semiconductors. Which would include any or all of the PCBs....Last edited by MrCreosote; 08-16-2021, 10:30 PM. -
Re: HiSense 55HtB power supply bench test: weird voltages
OK found the following definition of the unrecognized pinouts. Also appears this board does not have a 5v standby. Here is a copy from another thread:
Where is the 5V pin on this board? I do not see one.
[url]https://www.badcaps.net/forum/attachm...3&d=1472170236[/url]
STB = PS-ON
SW = BL-ON
PWM = PWM dimming
RE: Measured Voltages: the 24v is troublesome: much higher than the 18v spec'd.
Also, the voltage measured with no power to board could be caps...Leave a comment:
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HiSense 55HtB power supply bench test: weird voltages
There was a power surge at home from "direct" (no sound delay !!!) lightning strike. Popped a 15 amp breaker for ceiling lights (old knob and tube wiring - perfect antenna?) "Fried" garage door opener buttons and remote, KVM switch, Magic Jack, and a ceiling fan motor.
And my 55" 6 year old Hisense Black Friday Walmart TV.
There is no Red standby LED.
I was wondering how to "jumper" the board on to test voltages thinking the STB pin would be one of the pins.
However, I decided to measure voltages at all 10 pins...
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