RC valve transistors are quite easy to replace, it just takes a while to carefully remove all the potting. I've got a couple of the transistors left over, but I'm not fixing any more PGMIII's just in case my super chipped F3 PGMII blows it's cookies.

I had to order the parts and they took a couple of months to come, but come they did and a PGMIII with dead valves was fixed. Yep, I was pretty chuffed.

If there's no spark fro the PGM then you'll probably find that one of the big caps has blown and oozed it's goo all over the place. I tried replacing one of these too. It took ages to remove the blown cap and then remove another (undamaged) cap from another blown PGM, and then solder it onto the legs of the first PGM. Fiered up the bike and it worked for about 2 seconds. Then sparks flew and the cap exploded. At that point both Paul and I jumped for cover and decided that we'd best put that in the bin. I've since tried again on another blown cap, but with the same results, so it wasn't the cap blown on it's own, but something else causing the problem.