Xantrex C60

[Jwillis]

I would supply a circuit diagram but unable to locate one even after extensive searching and asking Xantrex is completely hopeless.Not sure what the big secret is,Oh well.

A friend of mine over loaded his C60 charge controller and turned it into a toaster.Apparently the capability isn't as high as he thought .Anyway ,I initially found that most of the IRF3205 power mosfets were toast.So I replaced them thinking that's all it needed.Bench tested at 10 amps and everything looked fine .I don't have anything to test it beyond 10 amps .Well I guess I'm Not very lucky.It seems that it gets hot again with less panels than his C35.So I rechecked the mosfets and of course  one was burned out again on the B side.I replaced the bad one again.
Under further investigation the A side remains fairly cool but the B side gets warmer when I bench test.It seems to me that all the Mosfets on A side and  B side should run at least on the bulk stage.
So something else is wrong.All the diodes ,resistors and caps check fine.I checked all the transistors in the upper region and they were fine but I replaced them anyway.I replaced the TL071CP as well although I'm sure what it's for just yet .Reverse engineering is no fun at all.
So I  figured I should check how the TC1427 is wired in and found that pin 5 out B drives one side and pin 7 out A drives the other.Both input pin 2 and input pin 4 are tied together. I seems to me that both outputs should be equal then if both inputs are tied together.Or is there something I'm missing?I'm not sure what to look for when checking the outputs.Or how I should check it .What I believe is a oscillation circuit is tied to pin 2 and 4 .I guessing there should be an oscillation at the outputs similar to the inputs.Or would I do a voltage check.
I was going to just replace it but I was sent the wrong ones (TC1426) which are inverting.The TC1427 is non inverting.So I doubt they're interchangeable.

Data sheet  list of the chips.
TC1427 http://ww1.microchip.com/downloads/en/DeviceDoc/21393D.pdf
TL071CP http://www.ti.com/lit/ds/symlink/tl072b.pdf
CD74hc4051-EP http://www.ti.com/lit/ds/symlink/cd74hc4051-ep.pdf
IRF3205pbf http://www.irf.com/product-info/datasheets/data/irf3205.pdf
PIC16C71 http://ww1.microchip.com/downloads/en/DeviceDoc/30272a.pdf
1H35SD  Is a mosfet ,checked on a transistor tester ,but could not find any datasheet for that number

[floobydust]

I would be suspicious of the gate-drive for the mosfets, is there is enough voltage to ensure they are fully on.
IRF3205 would like over 6V cold so I expect the TC1427 power to get, say 10V.

If they're all N-ch mosfets, some on the high-side I think there should be a boost-converter somewhere to make the extra gate-drive voltage. But I don't see any inductors on this PCB?
If you missed a faulty mosfet with a shorted/leaky gate, then it could lower thge gate drive as well.
1H35SD is actually a FFD8447L (look at part number under that text line on the dpak).

Reverse-engineering something like this is easier if you take picture of the pcb backside, flip it, and superimpose the component-side. The power electronics section is all I would sketch out.

[Jwillis]

Thank you for replying.
I am suspect of the driver as well because everything else checks fine .I socket ed both 8 pin chips ,as you can see ,so when the correct driver arrives I can just pop it in and retest it then .Both outputs of the TC1427 are tied directly to the gates and since both inputs on the TC1427 are tied together then one side can't be running independently from the other.So the PIC must be controlling it by turning the TC1427 on or off depending on the voltage state of the battery.
I looked high and low for a datasheet on that 1H35SD .Not sure how accurate those DIY transistor testers are but it hasn't lied to me yet.With that it seems fine.
In the mean time I'll put together some kind of schematic since the Xantrex people are being so dumb.Put it on the internet .That'll show them 

Appreciate  the help thank you.