Duo / DuoLE Vu-duo is Dead

Couple of information for those who need it
and know Electronics

Input voltage for all three regulators is abt 5.2 V on input coil s (left from ICs)
The capacity that they have changed is the input capacity (c807)
There is still more capacitors for filtering in input and output.
Oscilloscope is a good base to look at these voltages.
======================================================
Regulators :

output voltage at the ICs output PIN 8
or at the entrance of the filter coil (right from ICs) is
reg 1 >> 2.52
reg2 >> 1.27
reg 3>> 1.32

at the other end of the coil (output)

reg 1 >>2.50
reg 2 >> 1.25
reg 3 >> 1.27

So it is possible to determine by measuring where is the problem
Whether in the main part of power supply or in this dc-dc regulators.
So first measure input voltage to be sure that the issue is not before the regulators.

Do not change / replace components if you're not sure that they are defective.
 
I am sure the regulator reg3 (No3 on photo) is dead (burned). On duo it's marked Pz 1021ai and universal name isAOZ1212 (cf previous post).
I have to remove it and replace it with the 330 uF but I don't know where to weld (souder) the 330 uF (1 pin of the 330 uF at the place of the Vin pin (pin 7) ? and the other one at the place of the fx pin (pin 1) ?. I don't know on wich pins I have to do that. It's a little bit chineze for me.

It should be easier for me if somebody could tell me : sample
Remove the aoz2012
You take the 330 uF and you weld (souder) it at the place of pin 1 and pin 8
connect the pin 4 and 2 and 5 together

I know that for electronician, it may look strange, but for me, it's the only way I can understand.

Thanks
 
Ok, I think I begin to understand. What burned out on my board is the regulator N03. I found the capacitor C807, and this this one I have to replace.
Does it mean that with this new capacitor, it will bypass the regulator?
 
Ok, 1 more question.

I need to replace the Pz 1021ai , are you sure it is a AOZ1212 and not an AOZ1021?
 
My friend,

You can not replace regulator if it is broken
because simply you do not have experience and knowledge to do so.
You must have also equipment for soldering.
Maybe you can replace only the capacitor and see if the receiver working.
Pay attention capacitor has a plus and minus.
 
ALPA said:
For those whose duo is still not working after replacing c807 here is the solution.

View attachment 7601

If you don't change c807 on time, and if you play and experiment with bricked duo with power switched on, the regulator (No3 on photo) will die. On duo it's marked Pz 1021ai and universal name isAOZ1212, there are 3 exactly the same regulators on duo (see photo), but note that all are outputing different voltages, this is from memory (measure before changing anything):
1. gives 2.5v
2. gives 1.25v
3. gives 1.15v

If you can find a spare (which is extremely difficult) just replace it and duo will work like new.

And if no spare is available don't worry there is a solution. Here is what we did:
We found manual schematic for DIY regulator that converts 5v to 1.25, and we made it
Took out the working regulator from position 2 on photo and istalled it into position 3 in place of defect regulator.
We manualy injected 1.25v from theDIY regulator directly into the output pins of 2nd regulator and whouala the DUO works like new.


Now the cause of this is simple, prolonged exposure to heat makes condensator c807 break, which can than break regulator. The position of c807 is very near HDD which creates heat especially if used extensively. Or if you have fan problems this can reduce the amount of air circulating which can be also cause. Or simply the batch of condensers used in some duo mainboards is not so good. In my case, it was after 2 and a half years of extensive use. And the new condenser costs just 5eurocents and the regulator costs 1 euro.
Click to expand...

Hello,

Can you post the schema you used to for DIY regulator that converts 5v to 1.25

Thanks
 
Hello colleagues !

I have in last 2 months big problem with my DUO.
Started like freeze in working with red light ON. Every day it happen few times. Also happen that stoped working and no anything on display !
I contacted my friend @alpa which had first simular problem and he told me that change capacitors C807.
I made it and change for same capacitor like original - 220uf 16v. It work few days and after again problem.
After that I gave propose to change all 3 capacitors (C807, C814,C850) which are in same line on motherboard but with higher capacity 330uf 16v.
I made it but problem come back after 2-3 days. After it I made test for voltage from PS to motherboard and all values are normal.
Also I measured 3 regulators from @alpa tutorial but it gives normal voltage values.

On the last I made test with pure flash image without any connected on box and without any back up or universes. It work normal few days and same problem start again.
So, problem is HW but I really do not know what I need to do any more. I am tired and dissapointed. If someone have some ideas or same problem which are fixed please write here or if someone have contact from Vu+ engeener which can help in this situation.

All the best !
 
ALPA said:
For those whose duo is still not working after replacing c807 here is the solution.

View attachment 7601

If you don't change c807 on time, and if you play and experiment with bricked duo with power switched on, the regulator (No3 on photo) will die. On duo it's marked Pz 1021ai and universal name isAOZ1212, there are 3 exactly the same regulators on duo (see photo), but note that all are outputing different voltages, this is from memory (measure before changing anything):
1. gives 2.5v
2. gives 1.25v
3. gives 1.15v

If you can find a spare (which is extremely difficult) just replace it and duo will work like new.

And if no spare is available don't worry there is a solution. Here is what we did:
We found manual schematic for DIY regulator that converts 5v to 1.25, and we made it
Took out the working regulator from position 2 on photo and istalled it into position 3 in place of defect regulator.
We manualy injected 1.25v from theDIY regulator directly into the output pins of 2nd regulator and whouala the DUO works like new.


Now the cause of this is simple, prolonged exposure to heat makes condensator c807 break, which can than break regulator. The position of c807 is very near HDD which creates heat especially if used extensively. Or if you have fan problems this can reduce the amount of air circulating which can be also cause. Or simply the batch of condensers used in some duo mainboards is not so good. In my case, it was after 2 and a half years of extensive use. And the new condenser costs just 5eurocents and the regulator costs 1 euro.
Click to expand...

Hi all

The component is not a Pz1021ai but a AOZ1021ai from Alpha and Omega semiconductor. I will try to get one and replace the defective one. I will let you know.
 
alaina said:
Hi all

The component is not a Pz1021ai but a AOZ1021ai from Alpha and Omega semiconductor. I will try to get one and replace the defective one. I will let you know.
Click to expand...
AOZ1021AI-New-quality-goods-SOIC8-Free-shipping.jpg
 
I found an european company selling the AOZ1021AI. I have ordered 10 pieces (can always be usefull for others). I am waiting for the delivery. I let you know
 
alaina said:
I found an european company selling the AOZ1021AI. I have ordered 10 pieces (can always be usefull for others). I am waiting for the delivery. I let you know
Click to expand...

Please, if You solved a problem with changing a regulators write it here and I'd asked you to send me the regulators that I try to fix problem, of course I would pay to You for them...I am from south Europe.
 
I was trying to change the cap with an 330uf High Frequency 24v up to 105c degrees but i get no piture but the box is starting as i can see that in the display
 
Hi,

my VU+ Duo don't start. Only the red light on the front ist on.
I replace the C807 but the Output via Serial is the same as before


BCM73350010
012
Shmoo Version=1.9

MEMC-00000000 RW=00000010 WW=00000049 G=00000001 R=00000008 W=00000016
MEMC-00000001 RW=0000000E WW=00000047 G=00000001 R=00000007 W=00000000 #$
3
COPY CODE
A
the "A" is the last Char. The Red Light is on the Display say nothing. The box was running a half year. No Changes where made (Software etc..) since the last Image (half year). The Image was VTI Image.
Any Ideas what i can do???
(ps. USB stick flash (different Sticks) or VU Util Flash via LAN + Serial wont work)
LAN Port 8Yellow light is on but no Link when it is connected. If i Powered on the box the cooling fan don't work.
 
ani21441 said:
Hi,

my VU+ Duo don't start. Only the red light on the front ist on.

If you Powered on the box the cooling fan don't work.
Click to expand...
Try powering the USB stick with a USB Blackhole older image (http://vuplus-community.net/board/threads/blackhole-vu-duo-1-6-5.3242/) before the bootloader was needed.
if that flashes to your box and it starts make sure that if your upgrading the image to a newer version install the bootloader which lets you flash lager images.
the bootloader can be found some were in the forums just search!
 
tango110 said:
I was trying to change the cap with an 330uf High Frequency 24v up to 105c degrees but i get no piture but the box is starting as i can see that in the display
Click to expand...
Since your box is starting ok after you replaced the cap your new problem is not to find in the powersupply I guess.
Try to reinstall and see if you get the picture back.
 
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