Thanks for the Reply.
Charging threw USB seems fine. The USB power initiates a quick fan spin.
I get 20V on all the ports and It was charging fine at about 1.5a or so, maybe 2 amps. Pretty sure the batt is fully charged now.
So now the USB sits and fluctuates between 40 and 100ma. And then about once a minuite it does a quick fan spin and USB power goes up to around 400ma for a sec.
There Is some Heat coming from the CPU once and a while. I was Wondering if it could be a shorted CPU but thats a total guess......
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820-01949 - A2337 - Quick Fan Spin for a Few Seconds. Charging and Main Rails OK
Hello,
This macbook wont turn on. Only a quick fan spin. Sometimes fans spin a few second. Somtimes they spin fast for a few seconds. Other than that no signs of life
All the Coils on the board have voltage and battery charges fine as well.
I noticed this not sure if it is suspicious:
PPVCC_CPU_PH1 / CPUCORE_SW1 = 40 Ohms (Flex Bv shows 90 Ohms)
=.023 Diode Mode (Flex BV shows .090)
I would appreciate som support in the diagnosis.
Th anks,
K...
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Re: LTO PS 4LA Powerred Speakers - Tweeter Audio Low
So i believe the whole problem with the low audio in the tweeter is in the "crossover"(?) area.
THe capacitor and resistor seem fine, so i would just like to bypass and add my own crossover if possible?
If i want to bypass this area and add my own crossover, Do i need to know the freqency of the tweeter. I couldnt find aything in the schematics, just that it is a 15W 8Ohm Speaker. Perhaps close is good enough?
I wouldnt mind just odering one on aliexpress....
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Re: LTO PS 4LA Powerred Speakers - Tweeter Audio Low
Ive just recived these in the mail. Im more incline to just pop one of these in, But with the Crossover being messup up i need to make one or figure that out.
Never did that before..
Any suggestions? Can i just put a Capacitor in Series or does it need a coil too?...
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Re: LTO PS 4LA Powerred Speakers - Tweeter Audio Low
Hey having some success...
Ive disconnected the mute circuit and the bass works fine, so continuing testing without it...
See photo:
Ive disconnect the +VIN from the Tweeter amplifyer chip by disconnecting the cap and resistor next to it.
If i connect the +VIN before the 220P Cap (right at the main input) i get louder volume but sounds like crap.
I found C18 (10P) which connects the In to the Out is no good......
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Re: LTO PS 4LA Powerred Speakers - Tweeter Audio Low
Took out the transistor and it seems fine.
Its a PNP and -.8V on the base so i think thats right that its on... But how then do you get the base voltage back up.
All the resistors in that areas measure fine. They are just tiny 1/4W guys.
I was going to trying disconnecting the mute pin on the Tweeter driver but its hard to get too, ill have to cut the pin off if i want to test that......
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Re: LTO PS 4LA Powerred Speakers - Tweeter Audio Low
Hello, thanks for the push forward.
I have the IC voltages and the voltages around R17.
R17 over 100 Deg C...
Z1 and R7 get hot as well.
Q1 on the bottom left has less than 1V difference between base and collector. Should it have -27.8v on the collector and emitter with only 1v Difference on the base?? Check transistor out of circuit?
THanks
Kevin...
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LTO PS 4LA Powerred Speakers - Tweeter Audio Low
Hello, I have two of these speakers with the same Prioblem. The tweeter volume is very low. I believe it happened after running them too loud.
There is a lightbulb on the tweeter output i tried shorting and no change.
The tweeters measure 6 ohms and it seems to play loud if i plug them into an alternate amplifier
There are a couple resistors and diode getting really hot in the mute circuit...
At the bottom left of image. R17 gets the hottest. Over 70 deg C
Z1 and R7 next to that get hot as well. Zener tests ok
I measured the...
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Re: A2197 / Ipad 7th Gen / 2019 - No Power / Low Current Draw
Awww, I realized the ZXW board is different then the one in the component placement pdf for the ipad 7
PDF's HEre post #4
[url]https://www.badcaps.net/forum/showthread.php?t=91409&highlight=a2197[/url]
So i redid all my readings from the first post.. Now I only get 1.8always and main, no other voltages... No luck yet...Re: A2197 / Ipad 7th Gen / 2019 - No...nent placement...
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Re: A2197 / Ipad 7th Gen / 2019 - No Power / Low Current Draw
I just found out there is a program called "Wuxijin" Seems way more resourcefull than ZXW and seems to way more diode readings. I might buy it today and see if there is more info on this tablet.
"WUXINJI VS ZXW Schematics Full Review 15 big difference"
[url]https://youtu.be/vnA2LlEtjNo?si=Ws8nkTtx6RHsfQGH[/url]
All of my Diode Reading in ZXW check out. Except ZXW is missing a few things like the charge port flex.
Ive attached the Diode Readings from ZXW....
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A2197 / Ipad 7th Gen / 2019 - No Power / Low Current Draw
Hello,
Ive been working on this ipad for a little while now. CPU reballing is a common issue needed on this model.
I wanted to try and verify there is not a PMIC Problem before reballing the CPU.
Powering 4.2V at the battery gives a 0-1ma Draw
Pressing the power button it jumps to 18+ma and settle at 15ma
Ive attached my Readings for many of the power rails.
THis is how the columns are layed out:
Ohms/ Diode / Voltage After power button Press / Injecting Voltage Reading
In the second...
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Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound
"RJP63K2, FGD4536 and a SF10A400HD diode"
The SF10A400HD diodes seem bad.
one of them tests .5 one direction and .1 the other direction
One from the other board tests .6 one direction and .2 the other way.
The closet i found in my parts was a uf5408. Not sure if its close enough but I tried that but still no luck....
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Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound
Thank you, I double checked the buffer board outputs (with it out of citcuit) and no shorts found their.
THe only odd thing i found on the buffer were the 4 bigger shorkey looking diodes test .012v in circuit. but test fine out of circuit .4v...
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Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound
Dangit, found 3 bad IGBT chips on the Aliexpress Y-Sus board.
What is odd is that one of the chips that was shorted was also shorted on the original board..."FDG4536"
Could it be possible something shorted on the YSUS Buffer board is toasting the mosfets on the Ysus Board. Or it came that way?
Spent a bunch of time today double checking mosfets and solderjoints, cant seem to figure it out with meter...
Would it make sence to try...
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Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound
In the last set of pictures, On the main power board, there are two small blue ceramic capaictors that are getting hot. They are on both sides of double diode attached that heat sink.
I took the double diode out. Tested a short on the board and injected voltage... the transformer in the middle of picture got warm.
As for the two smallest boards, i havn't touched those at all. The big chips on each one are getting warm.
***SOMEHOW MY IMAGES BELOW GOT ROTATED>
PLEASE ROTATE THE...
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Re: Samsung Plasma PN43E450A1F - No Picture / Pop Sound
Thanks, Here are the pictures..
I forgot to mension a few things.
Once you hit the power button the green LED on the small board in the middle blinks one second on on second off.
Also the customer said that after the pop and no picture, the sound was still working....
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