A21m reboots

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frankiepankie · #1 Post by **frankiepankie** » Sun Apr 20, 2008 8:40 am

I have a A21m sitting here, which sometimes instantly reboots at bootscreen, all lights go on/off, i hear the DVD drive spin up/down, HDD on/off, all like a madman

How can i fix this?

I tried using only AC > same
Battery only > Same
Reseat ram > same
reseat CPU > same
Didn't replace the CMOS because i measured it with a multimeter, and it was fully charged

A sidenote: It doesn't always act this weird, sometimes it will work without a problem.

#2 Post by **Harryc** » Sun Apr 20, 2008 10:04 am

Pull out any MDC or mPCI modem, NIC, or WiFi cards. Now try it ....

frankiepankie · #3 Post by **frankiepankie** » Sun Apr 20, 2008 10:20 am

Nope, doesn't work.

Doesn't matter what i do.

If i try to boot Windows XP > reboot during logon
If i try to install Windows 2000 from CD > reboot during setup

A few minutes ago, i was able to boot into XP, i checked the temperature with Mobile Meter, it showed 42C idle.

But after i had booted in XP, and checked the temperature, it suddenly went into a black screen, and HDD spins up/down.

frankiepankie · #4 Post by **frankiepankie** » Sun Apr 20, 2008 10:23 am

A little question:

Could it be that my A21m is giving this problems, because of using an unofficial IBM AC adapter?

When i bought this A21m (it had a CRC error, which i fixed) i got it with an unofficial power supply.

It was working, but it thought it would be better to use an official IBM adapter (which it is working with right now)

#5 Post by **Harryc** » Sun Apr 20, 2008 11:01 am

What is the exact manufacturer/model/part# of the installed RAM. Are there 4 or 8 chips per side? Will memtest86 run? I don't think using an aftermarket AC adapter would hurt anything as long as the output is within specs? Do you own a multimeter? Measure the DC output on both adapters (center pin to ground)

frankiepankie · #6 Post by **frankiepankie** » Sun Apr 20, 2008 11:19 am

Un-original AC adapter:

14,92V (On the sticker it states 15V 3,0A)

IBM AC Adapter (I am using this one right now

)

16,29 ~ 16,30V (Sticker states 16V 4,5A)

RAM could be a good guess. I remember slightly that it didn't cause this problem before the RAM upgrade.

Memtest86 doesn't output errors after running for 3 hours or so.

RAM DIMM #1:
4 chips per side (Hynix chips)
IBM 20L0265

RAM DIMM #2
8 chips per side (Kingmax chips)
MSPB63S-68KX2

Google tells me that both are PC100 sticks.

Harryc, do you think the RAM stick with 8 chips per side is causing my problems?

That would be an easy to fix problem

I will try if my A21m will work fine with only the original IBM dimm.

#7 Post by **Harryc** » Sun Apr 20, 2008 11:23 am

It the A21m is anything like the T21's or T22's I've owned, it likes low density RAM (8 chips per side). So, if anything I'd say it was the Hynix rather than the Kingmax that is the issue. I'd try both one at a time.

frankiepankie · #8 Post by **frankiepankie** » Sun Apr 20, 2008 11:31 am

I tried it already before i read your last message

But it didn't work.

With only the Hynix one inside > still reboots
With only the Kingmax inside > still reboots

I also tried things like putting Kingmax in DIMM slot #2, instead of DIMM slot #1 but that didn't help.

Same with the Hynix stick, so i think the RAM memory is not the problem.

#9 Post by **Harryc** » Sun Apr 20, 2008 11:41 am

Try removing the hard drive and dvd drive. If that's not it, it sounds like a systemboard problem. Check the inductors. Do a forum search for 'inductor' for more information.

frankiepankie · #10 Post by **frankiepankie** » Sun Apr 20, 2008 1:14 pm

Without HDD and DVD it still reboots, or gives a black screen.

I am now sure it is a systemboard problem, so i will take it apart, and look for the inductors and the capacitors (capacitors are also known to fail, and cause problems)

Thanks already for giving me some tips Harryc

frankiepankie · #11 Post by **frankiepankie** » Sun Apr 20, 2008 1:45 pm

Alright, i have it lying apart right now, but i don't see any loose capacitors. I also didn't found a inductor in the base, so i am sure there didn't come any inductors off the systemboard.

sjthinkpader · #12 Post by **sjthinkpader** » Sun Apr 20, 2008 2:17 pm

With the FDD, Ultrabay cage removed, boot the computer pass the BIOS screen. Then press the MB by hand in various places to see if anything is loose.

It would be easier using a KB with a long flex cable such as R30, R40 but you have to remove the plastic guide around the A21m KB connector first.

frankiepankie · #13 Post by **frankiepankie** » Sun Apr 20, 2008 2:49 pm

Whuhh, this problem is driving me crazy

When i boot the ThinkPad, it shows the IBM splashscreen, i press F1 to enter BIOS, and it shows "Entering IBM BIOS setup utility" and then goes into a black screen.

When it is in that black screen, i hear very soft crackling sound from the inductors beneath the UltraNav buttons.

How the ..... can i fix this ?

#14 Post by **Harryc** » Sun Apr 20, 2008 3:04 pm

Here's one solution
Post on the marketplace forum asking for an A21m systemboard part # 08K3264 is another way to go...

sjthinkpader · #15 Post by **sjthinkpader** » Sun Apr 20, 2008 3:16 pm

The best MB for a XGA A2x are FRU:

26P8102
26P7984

These are 8MB video memory 900Mhz/1Ghz CPU versions. They were used in the final XGA A22m 2628-Txx.

Edit:
12P3979 also.

#16 Post by **Harryc** » Sun Apr 20, 2008 3:24 pm

sjthinkpader, nice addition to this thread. I just picked a part number for the original machine. frankiepankie can potentially upgrade and fix the A21m at the same time, very nice.

frankiepankie · #17 Post by **frankiepankie** » Sun Apr 20, 2008 3:39 pm

I have resoldered the inductors, just in case but it didn't help.

Still reboots.

sjthinkpader · #18 Post by **sjthinkpader** » Sun Apr 20, 2008 4:13 pm

Harryc wrote:sjthinkpader, nice addition to this thread. I just picked a part number for the original machine. frankiepankie can potentially upgrade and fix the A21m at the same time, very nice.

Yes, in those years, I was forever looking for these MBs along with the SXGA+ and UXGA versions.

A21m reboots

A21m reboots

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