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Saber III - LCD backlights dead - any fix?

Posted: Sun Sep 01, 2013 4:59 am
by g8tzl2004
I have a UHF Saber III where the LCD backlights are dead.

I understand that there are 2 green LED's at each side of the LCD - neither light up.

I presume one or both of the LED's are blown?

Is it easy to replace the LED's?

Could the problem be due to another fault?

The backlights work on my other Sabers which are the same age - so I'm not sure why BOTH LCD backlights are dead...unless they are wired in series so if one blows the other will no light up??

Thanks

Re: Saber III - LCD backlights dead - any fix?

Posted: Thu Sep 05, 2013 10:41 am
by g8tzl2004
Any ideas?

Re: Saber III - LCD backlights dead - any fix?

Posted: Thu Sep 05, 2013 4:53 pm
by spectragod
Bad LED(s), one of the legs came off from the LED(s), pretty simple to fix......... unless things go to hell.

Re: Saber III - LCD backlights dead - any fix?

Posted: Fri Sep 06, 2013 6:22 am
by g8tzl2004
Thanks

If one LED is bad, does that cause the other LED not to light up?

Re: Saber III - LCD backlights dead - any fix?

Posted: Fri Sep 06, 2013 8:01 am
by spectragod
g8tzl2004 wrote:Thanks

If one LED is bad, does that cause the other LED not to light up?
Depending on how the curcuit is built, yes. I don't have a service manual to reference though.

Re: Saber III - LCD backlights dead - any fix?

Posted: Sat Sep 07, 2013 10:41 am
by KF5LSC
spectragod wrote:
g8tzl2004 wrote:Thanks

If one LED is bad, does that cause the other LED not to light up?
Depending on how the curcuit is built, yes. I don't have a service manual to reference though.
Your post got me thinking, so I spent about an hour sifting through the Astro Saver service manual and circuit diagrams. Although I found information on the display flex connector pinout and the B+ source for the LED lighting, there is no schematic diagram of the display/ keypad in the Astro Saber detailed service manual. That seems like an odd oversight, unless I am missing one of the diagrams.

In any case, it looks like the display PCB can be removed from its mount by straightening out four retaining tabs. Any open connections at the LEDs should be (hopefully be?) obvious with a close visual inspection.

Re: Saber III - LCD backlights dead - any fix?

Posted: Sun Sep 08, 2013 9:24 am
by spectragod
KF5LSC wrote:
spectragod wrote:
g8tzl2004 wrote:Thanks

If one LED is bad, does that cause the other LED not to light up?
Depending on how the curcuit is built, yes. I don't have a service manual to reference though.
Your post got me thinking, so I spent about an hour sifting through the Astro Saver service manual and circuit diagrams. Although I found information on the display flex connector pinout and the B+ source for the LED lighting, there is no schematic diagram of the display/ keypad in the Astro Saber detailed service manual. That seems like an odd oversight, unless I am missing one of the diagrams.

In any case, it looks like the display PCB can be removed from its mount by straightening out four retaining tabs. Any open connections at the LEDs should be (hopefully be?) obvious with a close visual inspection.
Your miles past me, I don't have a service manual for a Saber. It does sound like one of those parts that they don't want you to fix, just buy new. The only problem..... they never expected the end user to keep the radio well past it's life cycle.

Back to the LED issue, being that I maintain a fleet of Crown Victoria's, 100 or so, most of the dash board and switches are back lit with LED's, I have repaired many back-lighting circuits by finding and fixing 1 LED leg that had broken loose, saved buying a new panel, and I like a challenge..... your results may vary.

Re: Saber III - LCD backlights dead - any fix?

Posted: Mon Sep 09, 2013 3:28 pm
by KF5LSC
To g8tzl2004:

In case you can't fix the LED issue and decide for a replacement, I found this gem on eBay:
http://www.ebay.com/itm/Motorola-NEW-As ... 1e7f27ada0

Re: Saber III - LCD backlights dead - any fix?

Posted: Mon Sep 16, 2013 5:56 am
by g8tzl2004
Thanks for your help.

My Saber III is just the analog version - its not the digital Astro Saber.

Is the LCD board for the Astro Saber identical to the analog Saber III?

I wondering if anybody has ever fixed the LED lights on a Saber III without just swapping the board. Is a dead backlight a common issue?

Re: Saber III - LCD backlights dead - any fix?

Posted: Mon Sep 16, 2013 8:05 am
by N4KVE
Years ago my Sys/Saber had a blown bulb. My friend who was a radio tech said it was much easier to swap the board, & that's what he did. He had a few laying around. GARY

Re: Saber III - LCD backlights dead - any fix?

Posted: Mon Sep 16, 2013 8:10 am
by KG4INW
g8tzl2004 wrote:Is the LCD board for the Astro Saber identical to the analog Saber III?
No, they are quite different.

Re: Saber III - LCD backlights dead - any fix?

Posted: Mon Sep 16, 2013 8:45 am
by g8tzl2004
How long do LED backlights last?