Orion A9 Power Distribution Board Capacitor Repair

Detailed analysis by K7HP of the 81936 A9 Power Distribution Board - Orion 565 and Orion 566 OII

From the Ten-Tec Reflector April 6, 2007

I came into the hamshack/office to start my day and found my Orion out of commission. The screen was dark and the ALC light was very slightly lit. When I cycled the power switch, I would get the usual double click of relays but the screen would actually turn darker than when it was off and the ALC light was faintly lit. The analog meter light would not come on as well.

Assuming it was a power problem, I took off the bottom panel and inspected the A9 Power Distribution Board. C6 was noticeably stressed with top protruding a bit in a classic electrolytic failure mode. It is a 470 uF 16 volt electrolytic - replaced it with a 470uF 25 volt one I had in the bin. Upon power up, the Orion came up as normal and with the last settings I remember from the previous day.

It occurred to me that the display back light seemed to be getting darker over the last week, but I didn't think anything of it until the hard failure.

It is an easy repair and it took longer to get the cover off than to diagnose and fix the problem. Hope this helps someone…

73,
Randy
K4QO

April 11, 2007

Had exactly the same problem on my orion I, to start with display contrast changed dramatically and then audio started to cut in and out. Switched OFF and then re-booted and radio was completely "DEAD". Fault traced to C6 but C7 & C9 were also changed as these were of a similar type.

Geoff - G0BYH

January 15, 2008

Screen went dark, panel indicators and meter lamps went very dim and receiver went dead. Had bottom cover off, exposing the power distribution board. Phoned T-T fast 'cause it was almost closing time. Paul immediately said he'd ship two caps for the distribution board, C6 & C7. They arrived 4-days later, over the weekend, and my three year old O was running on the fourth day. No charge. Thanks, (St.) Paul.

73, Roy K6XK

June 25, 2008

About 10 months ago, the capacitors on the A9 Power Distribution board failed, and I sent the radio back to the factory to get it fixed. Well, just 10 months later, the same thing happened again. This time, I decided to fix it myself with premium capacitors purchased through Mouser. The fix worked! The 470 uf, 16 Volt, 85 degree C caps, C6, C7 and C9 were replaced with ultra-low ESR 50 Volt, 105 degree C units that fit perfectly in the board.

I have a whole page on my website for anyone interested, including pictures and ordering information for the caps. Hopefully, these will last longer than the first two sets!

http://www.n6ie.com/A9_Fix.html

Ron N6IE
www.N6IE.com

January 25, 2010

On 1/24/2010 I was on 80 meters and my Orion II "2006 serial number" I notice the receiver cutting in and out and the color display not at the same contrast. I also notice a cracking sound when I went from 80 to 10 meters which you can hear the internal relay switching. Which was not normal but the relay is.

I shut the Orion II down and did a master reset thinking maybe the CPU got confused. After the reset the receiver was still cutting in and out. I shut down the Orion II again and then turned it on again. Now the Orion II was showing all the symptoms like the above post. I removed the PDB a9 and found c6 puffed out.

I wanted a quick fix and did not have the parts. Went to Radio Shack and in the parts draws found 470uf 35 volts 85 degrees. Better then the Ten-Tec caps. Purchase three to replace all three caps c6 c7 c9. As Ron N6IE stated not easy to get out but with patients it can be done. Replaced all three caps and the Orion II is working fine so far. I would replace all three caps to keep things in balance then to just replace one cap. The RS caps were a $1.39 a piece. Part # 272-1030.

So we will find out how these caps will work and update the post if there is a problem.

73'S PETE KG2J

January 29, 2010

Update - contacted Ten-Tec service department. Tony from service department stated Orion II now comes with upgraded c6, c7, and c9 caps which are 470uf 35v 105 degrees, low ESR. Original caps 470uf 16v 85 degrees not low ESR made by IC. The Radio Shack caps are made by Xicon 470uf 35v 85 degrees "not low ESR" but will work and how long is another question. Will update again when I receive the replacement caps from Ten-Tec.

KG2J

January 12, 2011

2 weeks ago I got an Orion1 and when I switched it on , I saw the display was a little dark in the upper left corner and was flickering during transmission. After studying the schematics and some measurements I found the reason. The +5volts on the power distribution board A9 was unstable. During transmission the 5V voltage alternated between 5 and 4,4 volts.

But changing the recommended board-capacitors brought no better results. Then I saw a difference between the board schematic and the circuitry on my A9 board: On my board the upper PNP -transistor was not the original type TO220P NTE 378. Ten Tec had used (how long?) another type BD246C .

Because this one is a TO3P Type and not fittable onto the bord , it was mounted very carefully at the factory via 8cm long wires beside the A9 board on the aluminum case.

I am very sure this outsourced transistor has worked in my Orion since it had left production (Serial Nr. 10C 10584 in 2005).

I ordered the the original NTE 378 from a semiconductor distributor, placed it onto the board and it worked perfectly.

DJ8LX