^^^
Honestly, you were looking to under-clock / overlock and that has nothing at all to do with whether the voltage setting will offer you a solution. Saying that, it does not mean the voltage setting is useless, and I can without doubt state that it definitely affects the hash and / or HW depending on your frequency setting.

And no, I still do not believe you run the different voltage settings to establish whether it had an effect on hashing / HW, maybe to look for your under / over volting, thus you are lying through your teeth! You can try it now, do a 10 minute run on any frequency (stock or above) with 2 different voltage settings (excluding 0000).

The OP's issue is most likely due to the way he's powering the rig in conjunction with an auto voltage setting. I'd say set the voltage to the recomended datasheet setting for the frequency he's running, then if the board "falls off" again, then it is without doubt a power issue.

You are lying through your teeth if you say you have run the full range of voltage settings without a noticeable difference to the hash and / or HW, an absolute lie! No difference to your multimeter readings I'd also argue is impossible, and remember to run the different vltages at the respective recomended frequencies in the datasheet too.

I take it you have looked at the cgminer code, and also looked at the datasheets(s) from bitmain to come to your evidenced conclusions. But to be absolutely & evidently certain that I am right, you'll have to de-assemble the S3 controller chip firmware (I can get you the raw file if you can't get it).

Suffice to say, the voltage setting in the UI is neither there by mistake nor a relic from another rig, if only that it was actually shipped at a latter date than the original S3 firmware.

Look at the cgminer code for S3 (or S2 for that matter) and the datasheet for the chip. Even better, do away with your multimeter and run the rig with different voltage settings and you'll definitely see the change in hash-rate and / or HW.

I agree, this is probably a PSU related problem.
The GUI voltage setting does not adjust the voltage at the board level (as / and there is no circuitry for that), rather at the chip level, and it is NOT a relic of other machines.
The stock / default setting for voltage is 0725 (or 0000 aka autovoltage), but the voltage setting will not magically cure an inadequately powered machine. Also remember, the voltage setting should be set according to the frequency per datasheet.

That's a great mod right there!
Those corsair fans should be as quiet as a whisper, and with a re-oriented S7 they could possibly do a wonderful job. I wonder though, what temps do you get with the S5? Also, what is the amperage rating on those corsairs?

If you prostrate at the alter of kano I can understand your point ... but you could have shut up, you chose not to, so  ...  keep digging ass licker!

You can not save face, damage has been done! You, kano and your bossom buddy ck are slimy.

Proof by admission, if any was needed, that puny pools are spamming the bitcoin network with bad block headers.
Take your trite back to your whingeing threads ...

Well, there is a new phenomenon where puny pools spam the bigger pools with corrupt block headers ... that may explain the seemingly inferior effective hashrate (and reduced luck). Slush always susses these things out and it is just a matter of time before all is good and dandy.

EDIT: Ignore: yes - says the kano alt ....

Don't listen to all these phising dimwits mumbling about the inferior puny pools.
The ONLY reason pool hash rate keeps steady (and growing) at slush is because it simply is the better pool. Luck shall turn and, as always, you'll get the full payout that you've earned at slush, which is not the case with those inferior pools (whose operators have resorted to spamming the network with corrupt headers).

May be a good reason to try a new configuration with the S7 ... as in having the fans strapped at the top / bottom top rather than front / rear (that'll require the unit being stripped though as top and bottom are sealed). That way, I suppose, even the fan specs can be downgraded as the distance to exhaust has been more than halved. (just a thought!)

That error, mostly, occurs due to not having the complete toolchain required to build the executable that your configure script is set to build. Ensure you have the mips-openwrt-linux toolchain before trying to compile.

Finally, and like slush said on facebook, a block with fees ..... apparently issue was due to an upgrade.
PS. For all the fans of luck .... this is your time to jump onto slush and ride it .... big tings r gwan!

Assuming you know what port-forwarding entails, the simple, straight-foward way would be to simply do your port forwarding to the defaul port 80 of the S7 on your gateway. (EDIT: You'd need SSH access to your gateway so that you change the gateway's default port  from 80 to another else you'll not be able to access the web interface of the gateway anymore!)

A more involved way, if you can not get the above to work: I think S7 uses lighttpd (lighty) as its web server, so all you'd need to do is change the port in the lighttpd.conf file (not sure where they keep it), but whenever you try to log-on locally, you'll have to append the port number to the IP. For external log-on, the port forwarding will cancatenate the port for you. Remember, after changing the conf file you'll need to restart lighty.
EDIT: Also ensure (if you use the latter) that the said 5-digit port is open in the firewall settings of the S7.

It may favour you, at times, to buy in USD rather than BTC and the reverse is also true (that most times), but that is why I said to keep an eye on the BTC / USD rate.
Buying BTC ... depends where you are but there are many exchanges AND individuals selling BTC. Make your choice and do your due dilligence!

Keep saving ... keep an eye on the bitmain site .... keep an eye on the BTC / USD rate .... it won't be many months before you can buy the latest. BUT before buying, read this forum for user experience on the miner you want to buy.

The simple answer is no you won't have enough BTC to buy the latest and best by running 2 S3's for a year UNLESS you solo mine and find a block (which itself is a lottery no end).

Well, the timing coincided with slush breaking down that long block .... go slush!

[MOD EDIT: Removed troll discussion reference]

It is a tad bad luck, but not unheard of, though for the week, we are now 89% which I have never seen that low on slush for the period I've been mining there, so yep, you can say it again .... bad luck!
Saying that, several (even a few!) weeks ago, we were popping a dozen blocks a day for fun and with a tad lower hash-rate, so the luck shall turn .... I am sure (following on from the invalids' saga recently) that slush will fidget about with something and the good luck will bounce back in no time.

I have not yet been able to put my hands on one of these, but I am currently drafting up some code to be able to run monitor on one of these (already have the code partially working on an S1 controller), so here's a request to whoever has one of these.
Could you kindly run via SSH and post the output here from the command cgminer-api '{"command":"stats"}'?

PS. Copying from the SSH window (in MS Windows) involves simply selecting the text in the SSH window then pasting into a message (no need to look for a copy command via right-clicking ... automatically done when you select the text.

@ITop_James - did you manage to get your order delivered after all?