Hi Sp00n1980,

I have an equal problem with my Ant. It hashed up to 2.1ghs/s then started to slow down. After restarting it, it never recovered and now I can get it only to 540mh/s but stable with no error. Before with 2.1ghs the error rate was below 1% until it slowed down (still not more HW errors). Between I tried a lot of stuff, frequency settings, CPU cooler directly attached, 2.5A PSU but still its slow...will try to figure out what went wrong if I find some time next week.

Greetings,

           miniasic.

Hi again,

ok, in Lab I have a regulatet PSU but that should be last resort to fiddle around in the circuit. I'll try to find out what U5 is. With 6 pins it seems to be an adjustable VR...but messing around on this SMD board...without proper tools...this will have to wait till tuesday.

Thanks,

           miniasic.

Hi,

I'd use 0A01 for 2.1GHs.

To chromsoma: Interesting, your PLL-Voltage is out of Specs and about 10% higher than mine. Maybe that's my problem...I'd guess
the to unknown ICs are VR for 5V -> 3.3V and one VR for PLL Voltage. Unfortunately I couldn't read the exact type and for the S1 boards bitmaint seems to have used other types.

Greetings,

            miniasic.

Hi again,

meanwhile I found some time to improvise a powered USB connector.

http://i.imgur.com/NhqTrX2.jpg

The plug is now powered by an external 5V 2.5A supply. USB signals D+, D- and Ground are connected straight through, power is supplied by external PSU and is routet over the blue jumper so I can measure current in case I want to know it. What I now have is:

USB Voltage 5.03V (while hashing)
USB-Serial converter 3.28V
PLL/Com: 0.998 V
ASIC: 0.83V

What I'd like to know is the voltage close to U5 (violet point) on the picture in below URL

https://bitcointalk.org/index.php?topic=390929.msg4681379#msg4681379

I think this is the PLL Voltage as the ASIC has different Voltages for Clock and Operation.
Operations Voltage seems ok but I'm not sure about PLL Voltage. Maybe someone can measure his Ant
for PLL voltage. Due to specs Core is 0.75 - 1.1V, IO is 3.0 - 3.6V and PLL 0.9 - 1.1. So my values should be ok, main USB-Voltage is ok, current of 2.5A should suffice even at much higher clock rates but my ant is still a better block erupter 

Greetings,

               miniasic.

Ok, more of this:

300.00 MHz | 2400 MHs | 1785 | 017 ms
306.25 MHz | 2450 MHs | 1805 | 017 ms
312.50 MHz | 2500 MHs | 1885 | 017 ms
318.75 MHz | 2550 MHs | 1905 | 016 ms
325.00 MHz | 2600 MHs | 1985 | 016 ms
331.25 MHz | 2650 MHs | 1A05 | 016 ms
337.50 MHz | 2700 MHs | 1A85 | 015 ms
343.75 MHz | 2750 MHs | 1B05 | 015 ms
350.00 MHz | 2800 MHs | 1B85 | 015 ms
356.25 MHz | 2850 MHs | 1C05 | 015 ms
362.50 MHz | 2900 MHs | 1C85 | 014 ms
368.75 MHz | 2950 MHs | 1D05 | 014 ms
375.00 MHz | 3000 MHs | 1D85 | 014 ms


or even smaller steps:

300.00 MHz | 2400 MHs | 2F86 | 017 ms
303.12 MHz | 2425 MHs | 3006 | 017 ms
306.25 MHz | 2450 MHs | 3086 | 017 ms
309.38 MHz | 2475 MHs | 3106 | 017 ms
312.50 MHz | 2500 MHs | 3186 | 017 ms
315.62 MHz | 2525 MHs | 3206 | 017 ms
318.75 MHz | 2550 MHs | 3286 | 016 ms
321.88 MHz | 2575 MHs | 3306 | 016 ms
325.00 MHz | 2600 MHs | 3386 | 016 ms
328.12 MHz | 2625 MHs | 3406 | 016 ms
331.25 MHz | 2650 MHs | 3486 | 016 ms
334.38 MHz | 2675 MHs | 3506 | 016 ms
337.50 MHz | 2700 MHs | 3586 | 015 ms
340.62 MHz | 2725 MHs | 3606 | 015 ms
343.75 MHz | 2750 MHs | 3686 | 015 ms
346.88 MHz | 2775 MHs | 3706 | 015 ms
350.00 MHz | 2800 MHs | 3786 | 015 ms


The timeout value is for the original cgminer-bitmaint version where you had to provision a timeout-value (default 20 * 100 ms). The slower the device is, the longer it takes to calculate the hash. bfgminer uses 1.5sec timeout for all values. cgminer-bitmaint uses the deployed value. After value * 100ms it times out the calulation an no nonce was found. You can see this for bfg and cg if you run it in debug mode.

Greetings,

            miniasic.

Hi,

yes, tried this. At the moment I'm on 550MHs again but due to freq. it should be 600MHs. I had to do this game several times but after the last "failure" I couldn't recover the miner. It was hashing at 2GHs and started to decrease hashrate over the day. At around 1.4GHs I restarted it and since then it never got over 600MHs again. I have to do very small frequency steps and around 100 Accepts before increasing frequency otherwise bfgminder or the bitmaint cgminer report 0 or something starting with c5xxxxxx after the getfreq command. If this happens the miner is f**** up again and I have to start with a lower freq until it recovers.

Thanks for your reply,

                 miniasic.

Hi again,

I now removed graphite magic again. R1 now gives me 1k and the non connected R2 is at 1.02k if measured in circuit. Voltage dropped to 0.83V again. Miner is still hashing to slow but hashing! Did anyone figure out what all the components on the board are?

I have:

Y1 25 MHz Oszillator (thats the 25 in the freqency formular)
U1 CP2102 USB to UART Bridge
U2 BM1380 ASIC
U3 503B or 5038 (hard to read) WTF?
U4 AOZ1021A Voltage Regulator
U5 5B402? WTF?

I'm interested in U3 and U5 because I still don't understand where the device stores it's calibration data but there seems to be something like that...and the serial protocoll the BM1380 speaks would be interesting, too.

Greetings,

              miniasic.

Hi,

just in case someone needs a finer speed setting:

Frequency    | Hashrate  | value | timeout
125.00 MHz | 1000 MHs | 0481 | 042 ms
137.50 MHz | 1100 MHs | 0501 | 039 ms
150.00 MHz | 1200 MHs | 0581 | 035 ms
162.50 MHz | 1300 MHs | 0601 | 033 ms
175.00 MHz | 1400 MHs | 0681 | 030 ms
187.50 MHz | 1500 MHs | 0701 | 028 ms
200.00 MHz | 1600 MHs | 0781 | 026 ms
212.50 MHz | 1700 MHs | 0801 | 025 ms
225.00 MHz | 1800 MHs | 0881 | 023 ms
237.50 MHz | 1900 MHs | 0901 | 022 ms
250.00 MHz | 2000 MHs | 0981 | 021 ms
262.50 MHz | 2100 MHs | 0A01 | 020 ms
275.00 MHz | 2200 MHs | 0A81 | 019 ms

or even finer for tweaking your individual miner:
237.50 MHz | 1900 MHs | 1285 | 022 ms
243.75 MHz | 1950 MHs | 1305 | 022 ms
250.00 MHz | 2000 MHs | 1385 | 021 ms
256.25 MHz | 2050 MHs | 1405 | 020 ms
262.50 MHz | 2100 MHs | 1485 | 020 ms
268.75 MHz | 2150 MHs | 1505 | 019 ms
275.00 MHz | 2200 MHs | 1585 | 019 ms
281.25 MHz | 2250 MHs | 1605 | 019 ms
287.50 MHz | 2300 MHs | 1685 | 018 ms
293.75 MHz | 2350 MHs | 1705 | 018 ms
300.00 MHz | 2400 MHs | 1785 | 017 ms

But beware. While playing around with this values or better some values not respecting the forumular given in the U1 manual I somehow wrecked my antminers clock generation.

Greetings,

                miniasic.

Hi,

you would send 160mA through the voltage divider -> 0.15W of heat dissipation are produced at the resistors.
A SMD 603 is rated at about 0.1W. So the 5kOhm are out of specs. Using 10 and 1.24 gives you only 0.085A and 0.07W in the 10k resistor what is inside specs. So my pencil stroke makes the 1k resistor to be massive out of specs 

Greetings,

              miniasic.

Hehe,

good luck with your battery. Due to my understanding of the VR I got about 3kOhm for R2 with my pencile strokes.

0.8 * ( 1 + 1/3 ) = 1.066V

Doing lesser strokes should result in a higher resistance what gives us a lower voltage. Measuring the resistor in circuit doesn't result in the correct value due to other components (L/C/AOZ) also being connected during measurement. If I measure R1 I get about 0.82k and 0.87k for my pencile strokes. Tested with my reference pencil on a paper I get about 10kOhm for one stroke of 2mm decreasing by about 1kOhm per additional stroke. Graphite has about 8 Ohm per mm²/m. Compared to copper this is rather bad.

The resistor measuring was done while the device was off/not connected to power. And my antminer was slow before I tried the pencil magic  It's not totally wrecked and is after the magic still as slow as before. But yes, your warning is correct. Shortening R1 would increase the Voltage and current flow throuh voltage divisor R1/R2.

Greetings,

              miniasic.

Hi,

I found a simple method to increase the voltage without soldering. On the image you can see several measurement points for different voltages on the antminer board. The USB voltage can be found between the outer pins of the the connector (red = 5V and black = Ground). Then we have two points near the USB - Serial converter which give us about 3.3V. Next you can find 1.1V close to U5 what seems to be the communication voltage of the ASIC. The relevant voltage for operation is the green point near U2. There are 0.8V (or in my case 0.86V in factory mode, what coud explain the differences in overclockability of the devices). Now to the interesting part. There is no need to replace both R1 and R2 just to follow the table in the U1 manual. The table there is more or less the same as in the AOZ1021AI datasheet. What I did was to use a medium hard pencil and do 3-4 strokes between the R2 connectors, plugged the device in an measured between black and green and voila I got 1.06V. You could easily do just one stroke for the start and see what happens with operation voltage. lesser strokes should give a higher resistance what would lower the voltage, so no risk in trying this. Unfotunately I "ruined" my device before this test (what made me bold enough to try it this way) so I can't tell you what hash rate I coud make after this modification. My antminer doesn't reach more than 450MHs as I can't clock it higher than 57.81MHz (0x1207). Somehow I messed up the PLL in earlier tests with small steps in clock rate and never made the device recover 

http://i.imgur.com/iFizDR3.png

Greetings,

              miniasic.