HUAWEI nb, RF Unit ALD Current Out of Range

[javierinfante]

hello:
Do anyone know why after nb restart or Iub configuration changes I got a RF Unit ALD Current Out of Range alarm?
I didn't change anything realted to the HW configuration, only Iub parameters, but after the nb restart I got this alarm, and I don't know how to clear because the nb was ok before the parameters change.
I have restarted the WRFUm but nothing changes.

thanks

[Handover24]

you are having problem on the TMA...check if locellgroup is configured wel according the new Iub or cellresource group...Regards.
which is the specific alarm cause ?

[javierinfante]

Hello, I have checked all parameters in the db and it looks ok, even more the site has three cells and only have the alarm.
The specific problem is overcurrent, I tried the comand reset ALDPWRSW because the ALD switch are off but after execute the reset command I execute the scan ALD and the result was the power switches of all ports are turned off.
regards

[Handover24]

So you must be very unlucky I think a TMA is damaged and not due to the configuration....try to replace the TMA of the cell with a new one.

[javierinfante]

hi, not tma in the site, only RET.
The thing that isn't normal is that this alarm just came after the nb restart, before was ok.

[Handover24]

ok if you do not have tma just sconfigure the tma if alarm is present this could mean that you have configured the tma ( maybe you have used CME with a default parameter settinng in my net on an UMTS site TMA is always present ).

[Handover24]

but the cell works properly or not ? are KPI for that cell ok ?

[Handover24]

here you are the procedure to solve that fault...( i'VE SOLVED MANY similar cases on my net just find your )
ALM-26530 RF Unit ALD Current Out of Range

Description

This alarm is reported when the current supplied by the RF unit to the antenna device through feeder or multi-wire cable is beyond the normal range.

Parameters

Parameter Name	Parameter Description
Cabinet No.	Cabinet number of the faulty board
Subrack No.	Subrack number of the faulty board
Slot No.	Slot number of the faulty board
Antenna Port	Antenna port (ANT A, ANT B, RET, ANT C, ANT D)
Board Type	Type of the faulty RF unit
ALD Working Current (mA)	Working current of the ALD (NULL)
Specific Problem	Specific Problem of the alarm(Overcurrent, Undercurrent, Overcurrent Protection, Disconnection Protection)

Impact on the System

Alarm Severity	Alarm Impact
Minor	The antenna device cannot work normally. In the case of an RET antenna, the antenna tilt cannot be regulated. In the case of a TMA, the receive sensitivity decreases.
Warning	The antenna device can work normally, but some secondary functions of the antenna device fail.

System Actions

• In the case of overcurrent, overcurrent protection, and open-circuit protection occurs on the antenna device, the RF unit automatically switches off the power supply to the antenna device. Meanwhile, the attenuation on the RX channel is set to 0 to minimize the impact of TMA fault on the receive sensitivity of the corresponding RX channel.
• In the case of overcurrent and overcurrent protection occurs on the antenna device, the RF unit switches off the power supply to the antenna device and then attempts to switch on the power supply every other minute. If the fault persists after three attempts, the RF unit does not retry any more.
• Five minutes after open-circuit protection occurs and the the power supply to the antenna device is switched off, the RF unit begins the attempt to switch on the power supply to the antenna device every other minute. If the fault persists after 26 attempts, the RF unit does not retry any more.

Possible Causes

• The configuration of the ALD switch is incorrect.
• The preset ALD current threshold of the RF unit is incorrect.
• The feeder connector is loose or waterlogged.
• The feeder is deformed.
• The jumper between the feeder and the antenna device is loose.
• The ALD power supply circuit of the RF unit is faulty.
• The antenna device is faulty.

Procedure

1. Check the configuration of the ALD power supply switch on the M2000.
   
   1. Run the MML command DSP ANTENNAPORT/DSP RETPORT to query the status of the ALD power supply switch of the RF unit. Check whether the status is correct according to the configuration plan.Y => The status of the ALD power supply switch is correct. Go to step 2.
      N => The status of the ALD power supply switch is incorrect. Go to sub-step b.
      
   2. Run the MML command MOD ANTENNAPORT/MOD RETPORT to modify the ALD power supply switch configuration according to the configuration plan.Check whether the alarm is cleared.
      Y => The alarm is cleared. No further action is required.
      N => The alarm is not cleared. Go to step 2.
   
   
2. Check the preset ALD current threshold of the RF unit on the M2000.
   
   1. Run the MML command DSP ANTENNAPORT/DSP RETPORT/LST ANTENNAPORT/LST RETPORT to query the ALD current threshold of theRF unit. Consult the related ALD manual for the operating current of the ALD. Check whether the ALD current threshold is correct.Y => The threshold is correct. Go to step 3.
      N => The threshold is incorrect. Go to sub-step b.
      
   2. Run the MML command MOD ANTENNAPORT/MOD RETPORT to modify the ALD current threshold of the RF unit according to the configuration plan.Check whether the alarm is cleared.
      Y => The alarm is cleared. No further action is required.
      N => The alarm is not cleared. Go to step 3.
   
   
3. Reconnect the jumper to the antenna port of the RF unit on site.
   
   1. Reconnect the jumper to the antenna port of the RF unit.Check whether the alarm is cleared.
      Y => The alarm is cleared. No further action is required.
      N => The alarm is not cleared. Go to step 4.
   
   
4. Check the installation of feeders for the RF unit on site.
   
   1. Check the installation of feeders for the RF unit.Check whether the alarm is cleared.
      Y => The alarm is cleared. No further action is required.
      N => The alarm is not cleared. Go to step 5.
   
   
5. Check the installation of jumper between the feeder and the antenna device on site.
   
   1. Check the installation of jumper between the feeder and the antenna device.Check whether the alarm is cleared.
      Y => The alarm is cleared. No further action is required.
      N => The alarm is not cleared. Go to step 6.
   
   
6. Power cycle the RF unit on site.
   
   1. Power cycle the RF unit on site. Wait until the RF unit startup is complete (the RUN LED blinking, ON for 1s and OFF for 1s).Check whether the alarm is cleared.
      Y => The alarm is cleared. No further action is required.
      N => The alarm is not cleared. Go to step 7.
   
   
7. Replace the RF unit on site.
   
   1. Replace the RF unit.Check whether the alarm is cleared.
      Y => The alarm is cleared. No further action is required.
      N => The alarm is not cleared. Reinstall the original board. Then, Go to step 8.
   
   
8. Replace the antenna device on site.
   
   1. Perform the corresponding operation according to the antenna device type.In the case of the RET antenna, replace the RET antenna.
      In the case of the TMA, replace the TMA.
      In the case of the SASU, replace the SASU.
      Check whether the alarm is cleared.
      Y => The alarm is cleared. No further action is required.
      N => The alarm is not cleared. Contact Huawei Customer Service Center.
      
      

[javierinfante]

Hello: Already done, even more the problem is already scalated to the field engineers to check the equipment, but what I dont understand is that it was ok before the restart and just after the restart the problem arises; and i have seen similar situations in a different nb'.
What I would like to know is if anyone knows if this is known issue, I mean after nb restart the ALD will fail.

[Handover24]

never find this kind of issue without a problem on the field or a configuration mismatch