Corona 2 beep no power - need an info about cap c7c8

[bgonev]

I desperate need help. I have Corona v2 with a "beep" problem. U1B1 - measurement are not OK, on the right side all pins have 0 Voltage. I've checked USB ports for any shorts, all are OK.
So I've started to look for bad capacitors, and this one give me 6.5 Ohm (basicaly shortened/blown as it is connected from one side to ground...) C7C8. So my request to you people is to help me if anyone have working Corona V2 to measure with OhmMether - resistance value of this C7C8 capacitor?

Thank you !

 

[stucknvegas]

You really cant test the SMD cap that way I tested a couple of my junk Corona boards on ohms and my meter is constantly on the move because its charging up whatever caps are in series with that one
If your thinking its blown remove it and test it with a capacitor meter NF pf uf Any corona board should test the same in that area Most of us here have had more failures than wins on slim power problems
Some of the basic test are the U5a1 and U5a2 regulators witch supply 5V- 3.3V and 1.8 Just remember anything in that circuit with c7c8 can give it a short

 

[bgonev]

You really cant test the SMD cap that way I tested a couple of my junk Corona boards on ohms and my meter is constantly on the move because its charging up whatever caps are in series with that one
If your thinking its blown remove it and test it with a capacitor meter NF pf uf Any corona board should test the same in that area Most of us here have had more failures than wins on slim power problems
Some of the basic test are the U5a1 and U5a2 regulators witch supply 5V- 3.3V and 1.8 Just remember anything in that circuit with c7c8 can give it a short

U5a1 and U5a2 are ok, I have all 5V- 3.3V and 1.8 voltages.. This particular capacitor c7c8 is exactly in this area (power related area) so for the moment is main suspect for corona's beeping and not turning on. Is it safe to remove it and try to power on the unit ?

Thanks,

P.S. if you have an corona mb, please measure c7c8 if it is s/c to ground..

 

[Antalpromille]

U5a1 and U5a2 are ok, I have all 5V- 3.3V and 1.8 voltages.. This particular capacitor c7c8 is exactly in this area (power related area) so for the moment is main suspect for corona's beeping and not turning on. Is it safe to remove it and try to power on the unit ?

Thanks,

P.S. if you have an corona mb, please measure c7c8 if it is s/c to ground..

Sure you can try but it won't help, that power line is that low and it's supposed to be.

 

[bgonev]

I'm not sure if I understand you: Are you saying that c7c8 has to be 6.5 Ohms ? Is it the same resistance value of this cap on the working Corona ?

 

[Antalpromille]

Yes, and that why you test components for shorts outside circuits.

 

[bgonev]

Thank you, appreciate your help ! Any other hints what can be wrong with this Corona ? As I said U1B1 is not giving 5V on the right pins, (I have 5V on pin3 and pin4, all others are 0V)

 

[stucknvegas]

testing on corona working V-4 c7c8 short to ground for me 5.7
U1B1= left pins all 5.V
right pins second from the top 5.V only the rest 0.V
I have seen a hand full of different corona 4 Gig machines flat line because of nand corruption
Once the south bridge looses its ready signal from the nand it stops the 5.V stand by at the USB hubs
The fix Convert to 16 M/B and if you had no previous nand dump the console becomes RGH only
You can test header pin area U1D1 AKA 4 gig QSB pins 1-16 post your results

 

[bgonev]

testing on corona working V-4 c7c8 short to ground for me 5.7
U1B1= left pins all 5.V
right pins second from the top 5.V only the rest 0.V
I have seen a hand full of different corona 4 Gig machines flat line because of nand corruption
Once the south bridge looses its ready signal from the nand it stops the 5.V stand by at the USB hubs
The fix Convert to 16 M/B and if you had no previous nand dump the console becomes RGH only
You can test header pin area U1D1 AKA 4 gig QSB pins 1-16 post your results

What should I test on U1D1 ? Voltage levels ? Resistance levels ?

Thanks

 

[nofeloniesyet]

if this is what i call a "dinger" lol, i have a shed full of slims here.sometimes ya get lucky and its easily tracked down.but in alot of cases,more often than not actually,ive never found a solution.if ya stumble onto something lemme know.if its something i havent tried yet i got a few to test on thats for sure,lol.

p.s: might wanna give reading over at cvx and bgamods sites as well.might be things listed there you havent tried yet.

 

[stucknvegas]

PSU plugged in test voltage ---no PSU test short to ground all pins

 

[stucknvegas]

No felonies you can test pin 2 for voltage all of my bad 4 gigs had 1.7 or so volts present
A good console no Volts present at pin 2
This test was done BGA top side nand not with small Physon controller configuration

 

[stucknvegas]

The one console V-2 that I did I could read but not write the nand
I had no clue what was the problem --so I kept formatting the nand in windows and eventually lost power beeps only
I did not test anything with a meter first -I did the conversion and all was good
Here is a video witch opposes my Voltage at pin 2 on Physon configuration
https://www.youtube.com/watch?v=SQEyg84fzxs&list=UUt3FaCy0WXOZfWdsgNF2iHQ&index=1

 

[Antalpromille]

The one console V-2 that I did I could read but not write the nand
I had no clue what was the problem --so I kept formatting the nand in windows and eventually lost power beeps only
I did not test anything with a meter first -I did the conversion and all was good
Here is a video witch opposes my Voltage at pin 2 on Physon configuration
https://www.youtube.com/watch?v=SQEyg84fzxs&list=UUt3FaCy0WXOZfWdsgNF2iHQ&index=1

Which pin 2 are you talking about? I don't understand what he's saying but when he measures U1D1.2 he shows there is no voltage present.

 

[stucknvegas]

He was testing physon controller configuration and his was no volts pin 2
The consoles I used pin 2= 1.7 volts method were V-4-and E-model V-6 all three I tested this way and fixed them
I am not sure but almost looks like he is bridging pin 1-3 for a second then testing pin 1# and displays 0 volts
my working V-4 shows pin 1# 3.3 volts Hope that makes sense

 

[stucknvegas]

Antalpromille you are more experienced than me with understanding electronics you went school
I come from the school of hard knocks and no training- But sometimes I get lucky and fix XBOXs

 

[bgonev]

Here is the metering of U1D1:

Pin - Voltage
1 - 1.33V
2 - 1.33
3 - 3.33
4 - gnd
5 - 3.33
6 - gnd
7 - 3.33
8 - 3.33
9 - 3.33
10 - 3.33
11 - 3.33
12 - 3.33
13 - 3.33
14 - 3.33
15 - 0
16 - 3.33

Resistance - No shorts beside 4 & 6.

Bad Nand ??

 

[stucknvegas]

OK My best estimate is the nand is your trouble
1# out the 6 I have done did take to the fix
and I offer no guarantee about my diagnostic plan
I wish I had a working V-2 to test against

 

[bgonev]

OK, so little progress:

I've tried about 100 times to read the nand, and 99 times failed (CRC error, failed geometry, etc..), and 1 time succeded . So maybe NAND controller is out, maybe nand itself.. So IF i have good nand backup, I can convert it to 16 MB and then re-flash it. I need someone (@Antalpromille, I saw that you have HowTo writen here ho to convert 4GB to 16MB, so maybe you can help me wit this one) who can check the nand dump (i'll send it) and give me "green light" to proceed with 16MB conversion.
This is my first time to do this procedure, so no previous expirience in this exact case.

Thanks to all

 

[Ac1dR3d]

v2 is alittle different to convert then v4...
i could drop you images if you want to...
anyway i tried v2 but was no good at that... so then i found the REAL guide... but now im out of *ding* consoles...