Spectra Caps and Fail 001

[btrains]

Hello group,

My Spectra, which is a D43 Conventional with an A7 control head, has been running fine, until recently. I've noticed audio popping since I bought it, but now some of the Rx audio is just not sounding right. Last week, I popped open the covers, and discovered the wonderous stench of leaking caps. I know that the caps need to be replaced, however, I am not able to do that at the immediate time. I need to set up a time with a friend of mine to replace the caps. However, the damage has already been done, especially to the bottom side board. There is a lot of damage to the green mask, similar to a picture on the repeater-builder site. Today, one of my test channels, which is the default 150.00 Tx channel no longer transmits with the Fail 001 error.

Obviously the caps have to be replaced, no question. But my biggest concern now is cleaning up the damage. How do I prevent the caps from doing any more damage for now? Do I need to just stop using the radio for the time being?

Let me know what I can do to salvage the radio. The radio Tx's nicely, and Rx's nicely too, except the fading now because of the caps.

Brad

[techie]

I would avoid using the radio, and if you can, take it apart, and give the contaminated boards a vinegar bath, followed by a distilled water or isopropyl alcohol bath.

[Will]

A isopropyl alcohol bath will not help. Try one of the diswashing soaps. Filtered water is a good rinse.
You are dealing with some nasty acid, copper sulfate and ect from the leaking caps.

[btrains]

So any dishwashing soap will do? Is there any specific cleaning process, or would I just use a shallow pan/bowl and put water and dish soap in it and let them soak?

This also doesn't have any adverse effects on the other, undamaged board components?

I tried isopropyl alcohol already, and that didn't work. I used it on a Q-tip.

Spectras are great radios, except for these caps. My contacts are checking to see if they have enough caps for the job, if not I'm compiling a shopping list to pick them up. Obviously an average of 50 cents/cap for a dozen caps is a small price to pay to keep this radio working in top shape!

[Will]

We here at the shop disassemble the circuit boards from the radio chassis. Then the circuit boards can be cleaned. We do not 'dunk' or let them soak.
Rinse with filtered water neutral PH, and let them dry for several days. Moisture under the ICs can destroy a board if not dried completly.
There is no guarantee that you get rid of the problem 'stuff' on the boards.

[kc7gr]

If the gunk has an acidic component, I would think that a dilute solution of baking soda and water could be used to neutralize it. Will, you'd know better than I would if such a trick would work (you've repaired more of these than I have).

Keep the peace(es).

[ke4zdg]

I've been fixing 900 MHz Spectras for the past 2 weeks that have leaky caps.

First step is disassemble the radio to the point where I can get the command and RF boards out. Then I remove the old leaky caps with my Hakko temp controlled iron. I then paint the pads with flux and heat up with the iron, adding more solder. Once the pads are pretty thick, I use my Edsyn sucker to remove all the solder. If you have trace damage, it will suck the pad right off the board (you can get around this by jumping legs of your new devices to other board connections; this is where your ohm meter comes in handy). Once I get all the old solder off, I dunk in a tupperware dish filled with 100% isopropyl and let it soak for at least 4 hours, swishing it back and forth every once in a while. Once it's done soaking, I hit it with an old toothbrush and let dry under a ceiling fan (takes 15 mins max). Once they're dry, I replace the old electrolytics with 50V tantalums (you don't need to replace with surface mount caps; through-hole will fit just fine, just trim it really short). Those are guaranteed to never leak.

Once you get your new parts soldered in, replace all the boards and plug all the cables back together. Don't forget the thermal grease on the AF amp on the command board.

You should probably realign the radio (oscillator warp, at least) once you replace parts on the RF board.