ASUS P4SP-MX rev. 1.0
At first start POST card said FF. All voltages (CPU, RAM, AGP, SB, NB...) OK!
I tried to take original EPROM from this MOBO and put him into MSI TL-46 POST card who can bybass MOBO BIOS and boot from external eprom.
MOBO start normaly!?
I desoldered eprom socket and soldered eprom directly to PCB.
POST FF again!
How to find what is preventing MOBO BIOS to laoad and alowes loading external BIOS?
p.s. I changet IT8705F, heated South and north, changed battery.
Прошивка и настройка BIOS, переделка и ремонт материнских плат, БП, видеокарт, HDD.
ROM.by 2002-2019 © apple_rom
Посмотрите куда идут линии данных с микросхемы BIOS на материнской плате
Here is the result of measurement of MOBO eprom:
- VDD= 5.3V
- RESET =5.3V
- #CE= 0V
- #OE =5.3V
- A0-A9 =5.3V; A10,A11 =0V ; A12-A17 =5.3V
- DQ0-DQ7 =0.9V
As I read in datasheet (in attachment) for W49F002U when #OE (output enable) is in High logic level (Vih) output is disabled. I don`t have enough expirience with this cind of problems and this is just common sence conclusion: If chip have disabled output how do I enable it? I tried to track where is it going and find nothing.
What about A11 and A12? Is it normal to all other adress imputs have 5.3V and they 0V?
And result of measurement of pins #WE.
Отправить комментарий