R2001C LVPS issue

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cahighwayman22
Posts: 193
Joined: Sun Jul 20, 2008 11:43 am

R2001C LVPS issue

Post by cahighwayman22 »

Greetings.

Got an R2001C that has an issue with the Low Voltage Power Supply. The issue is that there appears to be a short somewhere in the supply itself. I have replaced all of the electrolytic caps, rectifier diodes, and even the 2N6436 transistors on the switching board. The problem is within the supply, and no where else. I removed the boards one at a time, and the issue isn't their. I've eliminated the HVPS (High Voltage Power Supply) as the issue.

When power is applied, the alarm tone is continuous, and its stuck that way.

Any ideas on anything else I should check? I'm pretty much am going to scrap the unit and sell it for parts if I can't get this resolved.

Thank you

-Trevor
DJP126
Posts: 873
Joined: Wed Jun 18, 2003 6:41 am
What radios do you own?: What's a radio?

Re: R2001C LVPS issue

Post by DJP126 »

cahighwayman22 wrote:Greetings.

Got an R2001C that has an issue with the Low Voltage Power Supply. The issue is that there appears to be a short somewhere in the supply itself. I have replaced all of the electrolytic caps, rectifier diodes, and even the 2N6436 transistors on the switching board. The problem is within the supply, and no where else. I removed the boards one at a time, and the issue isn't their. I've eliminated the HVPS (High Voltage Power Supply) as the issue.

When power is applied, the alarm tone is continuous, and its stuck that way.

Any ideas on anything else I should check? I'm pretty much am going to scrap the unit and sell it for parts if I can't get this resolved.

Thank you

-Trevor

Trevor, it sounds like this is not a power supply issue but a possible issue with the RF I/O (A11) module. A LVPS problem usually causes constant rebooting of the analyzer (shutdown/powerup) not a constant alarm. Another possibility is a constant over dev alarm. If this is the case, you can disable this by setting over dev to 0.00KHz. in the monitor screen.

Since you have an R2001A with a squelch problem, try swapping the rcvr modules between these two units to see if the squelch problem disappears. You can also swap the RF I/O modules to see if that is your alarm problem. If your problem is there, it will be in the wattmeter section or the wideband amp section.

Good Luck,
Dave
cahighwayman22
Posts: 193
Joined: Sun Jul 20, 2008 11:43 am

Re: R2001C LVPS issue

Post by cahighwayman22 »

Hi Dave

The monitor doesn't even come out of booting up, and it doesn't reboot constantly like my R2001A did. I disconnected the A11 module, and that didn't make a difference. It's basically stuck in boot mode, and doesn't come out of it. The 2N6436 transistors on the switching board get hot, which tells me that the LVPS is being over driven in some manner. The DC bus measures 20VDC before I power it up, after I power it up the DC Bus voltage drops to 12VDC. Not sure that has something to do with it.

-Trevor
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