Re: Dell Inspiron 5100 laptop motherboard components questions

BillJohnston wrote:
> I have three questions:
> 1. Is this a multi-layer motherboard?
> 2. What is the value of zener PZD1, 57 2, green band, violet band and
> wider red band?
> 3. What I believe is an inductor, PL4, seems not to be in the circuit.
> I suspect a through hole open. There is a trace going nowhere directly
> off of pin 2 of the power supply socket that appeared to go to a through
> hole which after removing the socket doesn't seen true. There is a
> trace from socket pin 2 to PL4 and from PL4 to another apparent through
> hole that goes nowhere from the other side of the board, hence the
> probability of a multilayer board.
>
> The former owner had juiced up the 5100 with a 70 watt CPU which I
> believe eventually created an open on the pin 2 circuit although there
> was a loose pcmcia spring clip under the board that was likely left
> after an earlier mb change. I believe the earlier mb change was a
> similar failure so the more likely cause is the 70 watt CPU cooking a
> conductor.
>
> I'd appreciate any help. Thanks.
>
> Bill
>
>
Bill,

It's definitely multi-layer. I am at a loss to answer your other
questions. For me, if a board refuses to boot after trying various
fairly routine steps, it goes to the local electronic scrap dealer.

The problem is that if you manage to somehow repair it and get it
running, there is no telling whether other components would soon fail
having been overstressed when the board crapped out the first time.
Hence, enter the local electronic scrap dealer.

70 watt CPU? Which stepping and speed? Too much heat and too much
current... Ben Myers

BillJohnston wrote:
> Bought another non-working motherboard to troubleshoot the original.
> Found I fried an octal tri-state buffer driver and have one on order.
> Got the other board working but now I'm confused and wonder if the CPU
> is damaged. It's a 3.06 Pentium 4M that's running at 1.594GHZ. I saw
> this on the first board and in retrospect thought it was because it was
> running on the battery. Now it's running on AC and still running at 1.5
> GHz. The BIOS has been updated to A32. When I got to WinXP System
> Properties it says it has a 3.06GHz processor running at 1.59GHz.
> So, I reboot into Debian Linux Lenny. I run Folding@Home. On an
> EVO N610c running FAH, with a 2GHz processor, 1% of a mini chaperonin WU
> takes 1 hr 41 minutes 14 seconds with a core priority of 95%. On an EVO
> N600c running a 1.06GHz processor, 1% of a mini chaperonin takes 2 hours
> 23 minutes 41 seconds. On this Insprion 5100 with a 3.06GHz processor
> (dmesg says it's a 1594.735MHz processor), I started a mini chaperonin
> at 02:04:30 UTC and it's presently 05:18:53 UTC and it still is working
> on its first 1% (core priority 96%). What gives?
>
> Bill Johnston
>
>
>

Question: With the 3.06GHz P4M running at 1.6GHz, does the motherboard
charge the battery? If not, then the motherboard has a snarled up
charging circuit. If so, could be the CPU.

If you have any Socket 478 2+GHz Celeron handy, install it instead, as
another check. The Latitude 100L (twin motherboard design separated at
birth) commonly shipped with a Celery chip... Ben Myers

BillJohnston wrote:
> Bought another non-working motherboard to troubleshoot the original.
> Found I fried an octal tri-state buffer driver and have one on order.
> Got the other board working but now I'm confused and wonder if the CPU
> is damaged. It's a 3.06 Pentium 4M that's running at 1.594GHZ. I saw
> this on the first board and in retrospect thought it was because it was
> running on the battery. Now it's running on AC and still running at 1.5
> GHz. The BIOS has been updated to A32. When I got to WinXP System
> Properties it says it has a 3.06GHz processor running at 1.59GHz.
> So, I reboot into Debian Linux Lenny. I run Folding@Home. On an
> EVO N610c running FAH, with a 2GHz processor, 1% of a mini chaperonin WU
> takes 1 hr 41 minutes 14 seconds with a core priority of 95%. On an EVO
> N600c running a 1.06GHz processor, 1% of a mini chaperonin takes 2 hours
> 23 minutes 41 seconds. On this Insprion 5100 with a 3.06GHz processor
> (dmesg says it's a 1594.735MHz processor), I started a mini chaperonin
> at 02:04:30 UTC and it's presently 05:18:53 UTC and it still is working
> on its first 1% (core priority 96%). What gives?
>
> Bill Johnston
>
>
>
I had a Latitude that would only run at half speed due to
fan/overheating problems. Might be worth a check.