4. ULTIMATE VTT SOLUTION
The combination results of EC10 and the Q6 regulator are shown below before ultimate modification is explained.
| BP6 revision | Regulator | capacitor | stability(W2K) | VTT change(high load) |
| 0.40 | LM317T | 1500 micro F | good | 0.21-0.52V |
| 0.40 | LM317T | 1000 micro F | startup unstable | |
| 0.40 | LM317T | 100 micro F | startup unstable | |
| 0.41 | LM317T | 2200 micro F | startup unstable | *Be Carefull !! |
| 0.41 | LM317T | 1500 micro F | good | 0.21-0.52Ｖ |
| 0.41 | LM317Ｊ | 100 micro F | startup unstable | |
| 0.41 | LM317Ｊ | 2200 micro F | startup unstable | *Be Carefull !! |
| 0.41 | LM317Ｊ | 1000micro F | good | 0.24-0.52V |
| 0.41 | LM317Ｊ | 1500micro F | good | 0.29-0.52V |
| 0.41 | LM350T | 100 micro F | startup unstable | |
| 0.41 | LM350T | 2200 micro F | startup unstable | *Be Carefull !! |
| 0.41 | LM350T | 1000 micro F | stable | 0.33-0.52V |
| 0.41 | LM350T | 1500 micro F | stable | 0.38-0.52V |
| 0.41 | LM338T | 1500 micro F | stable | 0.36-0.52V |
According to these results, the combination of LM350T and 1500μF is the best.
*If you use 2200uF for EC10, many freezing occurs in OS boot or runnning.
However, because the change of VTT was anxious, I've hit on to input 5V to the Q6 regulator.
VTT MODIFICATION
1. CHANGE EC10 ELECTROLYTIC CAPACITOR
This is a famous VTT topic by BP6COM.
Change EC10 100 micro F to 1500-1000 micro F(6.3v) capacitor.
2. REGULATOR MODIFICATION
a)THE HOLE
First of all, paper is placed between CMOS battery terminal, and the battery is turned off.
The hole is made for the BP6 board. From the beginning only to removing solder of hole which has become empty.
The hole is located in just right of the COM connector.
This is used to wire the back of the motherboard.
b)LM338T
LM338T Vin 4.2V, output 5A (peak 12A)
The terminals of LM338T are bent like this.
Left Vadj terminal and center Vout terminal are to solder with the motherboard . Moreover, right Vin terminal is to float from motherboard.
c)EC12 CAPACITOR
Solder is applied back and the EC12 electrolytic capacitor is blown down a little left. Do not remove.
d) Q6 REGULATOR
A left terminal and the center terminal of LM338T which applies the heat sink are soldered with the motherboard beforehand.
A right terminal must be floated from the motherboard.
e) 1000 micro capacitor
The wire is rolled, and soldered with + side of 1000 micro F(10v) capacitor beforehand.
A black wire is soldered with the EC12 minus terminal. Then capacitor plus terminal (Red wire) of 1000 micro F is soldered with a right terminal of the regulator.
Wire the back of the motherboard for a red one, and solder with the terminal of 5V ATX (The fifth terminal from the right).
The ALPHA heat sinks are installed in cpu.
f) NOW BOOT !!
I 'm using RU VP6 modified BIOS by JOHN.
BIOS SCREEN
Set FSB100(1/3), x8, 2/3 AGP and Speed Error Hold is Disabled.
BOOT SCREEN SHOT
Now Windows 2000 started.
3. RESULT
Surprisingly, VTT falls only on 1.49V while the media player is operating.
Because VTT especially falls only by 1.46V while 3DMARK operating.
My Pentium III 800 Dual system is quite stable. Please Try it !!
The screen shot below is the one that the
vtt value of fluctuations after 3dmark2000
ends was shown.
See Core1.
BP6 REVISION AND VERSION
I modified 4 pieces of BP6 including my friend's.
BP6 rev 0.40 ver 1.0 ----> 2 pieces
BP6 rev 0.41 ver 1.0 ----> 2 pieces
All are OK. Don't worry about rev 0.40, if you have !
Also Japanese user send me success mails. They use PEN III 600E(CC0) DUAL on BP6 rev 0.41 ver 1.0 by this modification
