LPC controllers

[spleenharvester]

How exactly do you go about debugging them?

I have plenty of no-POST boards here with various flashing LED combinations, e.g HP 6735s with 5 flashing caps lights (KBC1091), L300/A300 with flashing charge lights (WPCE775L) which refuse to boot.

And looking at the schematic, every voltage appears to be there, and the LEDs can be traced back to the LPC controller, but no further.

How exactly are you supposed to debug the LPC to find out what the problem is/why it's giving out these flashing LEDs? If I could figure this out I could probably fix an awful lot of boards.

Also, in cases like these where all voltages appear present, is it worth flashing the BIOS? If so is there any way of doing this without an expensive programmer?

[dj_ricoh]

Re: LPC controllers

ezp programmer its a must have tool in shop and its no exp.
what i don`t understant about flashing that its very hard get the .rom file.
i saw a lot of .fd files but i don`t understand; its that a type o bios or parts?

hp usualy gives you 1mb 2 mb 4mb and they got .fd extension
anyone try to flash with that extension or you need to rename it in to .rom

[ala_borbe]

Re: LPC controllers

i have two programmers, self-made willem and cheap SPI programmer

bios extension is not a problem, extensions don't matter, but size does

if file is 1024 bytes, 2048 bytes no matter the extension, just erase EPROM, confirm erase, write new file, and verify written

but on laptops often file is larger than EPROM... that indicates that KBC/EC bios is also included in file, and flash program (vendor utill for flash) knows how to use it, its very hard to program that file with EPROM programmer, but KBC/EC part can be "cut" from file and the programmed

also take note that most laptops wont power on if KBC/EC version and BIOS versions do not match

[japlytic]

Re: LPC controllers

I found that on a certain Mini-PCIe slot in some systems, the following LPC bus signals are present on the following Mini-PCIe signals (e.g. UIM_PWR pin has LPC Frame instead):

SIM C8 (LPC Reset)
SIM C4 (LPC Clock)
+3.3V Aux
UIM_PWR (LPC Frame)
UIM_DATA (LPC AD0)
UIM_CLK (LPC AD1)
UIM_RESET (LPC AD2)
UIM_VPP (LPC AD3)

[ala_borbe]

Re: LPC controllers

have cheap Mini-PCIX debug card, either is faulty or i dont know how to use it

but i use PCI debug card to debug desktop boards and it works

intel has detailed doc about lpc debug...


and some other approach

https://online.tugraz.at/tug_online/...?pCurrPk=59565

[spleenharvester]

Re: LPC controllers

Damn, nothing in there about GPIO or hard power offs or anything :/ I'm guessing the KBC chip incorporates both the LPC bus and other functions, i.e the voltage monitoring?

Interesting that there's no power if the KBC chip has different firmware. Honestly I believe if we could figure out how these things monitor voltages etc we could fix an awful lot of kit.

[spleenharvester]

Re: LPC controllers

A bit of progress. Found this:

Take a look at the power sequence diagram. Very similar to stuff used in the 6735s.

As we can see, there are lots of powergood signals going to the KBC chip. The KBC chip I'm guessing sends KBC_powergood to the NB and SB only when these voltages are in check. If they aren't, we will get the 5 flashing caps problem.

This is further supported, I feel, by the fact that removing the NB from a 6735s board will also (apparently) result in 5 flashing caps.

The problem is - I can't find any obvious "powergood" signals on the 6735s schematic going to the KBC chip. Maybe they're named differently. What gives?

[rajeshkumar]

Re: LPC controllers

Damn, nothing in there about GPIO or hard power offs or anything :/ I'm guessing the KBC chip incorporates both the LPC bus and other functions, i.e the voltage monitoring?

Interesting that there's no power if the KBC chip has different firmware. Honestly I believe if we could figure out how these things monitor voltages etc we could fix an awful lot of kit.

hiii im knowledge seeker
can u guide mee hows the kbc working
some time im facing problem motherboard not on im replace the kbc also
?????? but there noo gud responce

[maestro_lpc]

Re: LPC controllers

When Hp 6735 caps flashing 5 time, it is problem AMD north bridge or CPU.
Try heat north bridge wiht hot air about 2,5 minute 420"C. When NB not working, there no post codes. Sorry my english!

[ktmmotocross]

Re: LPC controllers

"2,5 minute 420C"

dude r u nuts?

[cyberhack]

Re: LPC controllers

Reflow 45 - 120 Seconds 205 - 225 ° C

[maestro_lpc]

Re: LPC controllers

420C its really on the chip 225C try measure it.

[highpulse]

Re: LPC controllers

i think he missunderstoof himself , when mentioning 420 degrees (possible hot air station value) not the value that he is giving to the chip :P

but does compaqs, have many problems with QFNs , i would chek them carefully for S3 states

[ktmmotocross]

Re: LPC controllers

420 is mega high even with hot air. my hot air station blow 280c air

[maestro_lpc]

Re: LPC controllers

I have solder station Lukey 852. And I repaired all AMD NB with this method.
Then they working about 2-3 month, same about 1 year. Good diagnose method.
Sorry my english.