IceCap 660 Teardown and Repair (mains cap failure)


My venerable IceCap 660 VHO ballast (which I use with T5 lamps) started flickering and would not restart. After smelling the sickly smell of popped electrolytics, I decided to test the "Repairable" moniker on the case.

(Disclaimer: the ballast operates at mains frequencies and power levels. If you do not understand the implications of this, do not attempt.)

First step not pictured: drilling out 4 rivets :(. Ok, so not the best for something repairable. I'll have to find a fastener to close the case.



Yup, thats popped. And sprayed everywhere. Ugh. These are Nichicon (good brand) 680uF 250V caps, 30x30mm footprint. Sadly, the fitted caps are only 85C.

At this point I removed the capacitors with solder wick and heating both pins at once. I'm electing to remove both, as this ballast has been in operation since ~ 2006 (date codes on components pin this as being made ~ 2003).

When dealing with popped capacitors, note that the electrolyte is pretty corrosive, and should be washed off with distilled water and/or isopropanol. It also stinks, so do it in the garage or outside :)

In case there is any other damage, or failed components, its time for a tour of the board:


The logic section. The connector on the bottom is for a dimming control signal, which is only really usable with VHO bulbs according to the instructions.

For the electronics folks, the main components:

IR2110 - gate driver IC

TL594 PWM controller:

LM339 Comparator:

555 Timer :bounce2: (time the ignition cycle?)

LM393 precision comparator


The ballast inductors.


The input section (with the caps removed). I've started the process of scrubbing the board down with IPA (not the beer!). Still lots of work to do. You can see the pad of the popped capacitor has already been somewhat damaged. Its totally workable though and doesn't really require any further work than removing any remaining electrolyte.


A current sense transformer (likely?) hiding under the big transformers. There is a row of passives under each of the two transformers.



I don't have the replacement capacitors on hand, but a 105C footprint compatible parts is $4.50 in singles on Mouser. Everything else appears to be in working order (the main IGBT transistors are intact, no burning smells or char marks, etc).

I'll followup with putting the new caps in place.


New member
I have an icecap, never realized they could be dimmed, anyone have any info on how it works, will it work with an apex?


New member
I have an icecap, never realized they could be dimmed, anyone have any info on how it works, will it work with an apex?

Don't know but I've got a solar 750 dimmer made for it that I'll probably never use again, PM me if your interested. I think they work off of 5 volt pwm (possible analog) judging from the guts of the controller and output, since the controller would run an LED driver but the dimming slope was very fast and in reverse from what it did from the ice cap ballast....


I can poke at the actual input. It appears to drive the opto-isolator directly left of the socket (U5). It was designed to only dim VHO bulbs which would limit its modern utility.


New member
Good stuff, tore mine apart years ago as it stopped working and found a cold solder joint near the LM339. Think if i was you would just replace all the electrolytic's on the board. Don't think you need a ESR meter to tell you the big mains caps are done:). At least for me there is not much use for the IceCap anymore. Even T5's day's in the sun are gone. Too bad IceCap couldn't keep up with technology and jumped on the LED bandwagon.