Service Forum

steve5214 · Membru Activ Joined: 07 Jan 2006 Posts: 61

Hi Victor/Bob,

Its been a while, hope things are well with you.
I have an A22m with CRC1 (non stable) if left at the CRC halt status it eventually reverts to a blank screen so the fault isnt just with the 24rf08 contents. Does anyone know what comonent/s cause the power problems ?

Cheers
Steve.

victor · S.F. Boss Joined: 07 Mar 2004 Posts: 2581 Location: Staff

See other posts around in the Hardware forum.

steve5214 · Membru Activ Joined: 07 Jan 2006 Posts: 61

Victor,

Sorry for placing the post in the wrong forum.

"The usual sympthom for the ADP3421 is, when you press the power on btn, the leds blink or lighten for a while then the laptop switches off."

I dont have this problem it runs to the crc1 error then will sit there for a couple of hours before it blank screens so i guess I have more problems than just the ADP3421.

Cheers
Steve.

steve5214 · Membru Activ Joined: 07 Jan 2006 Posts: 61

Victor,
I found this on another forum -

I have come accross several A22m, A20m, A21m, T20, T21 laptops, which gives a common power-n problem. There are so many defective boards floating around because of this know failiure. I hope IBM has rectied this problem. To be more specific about the problems.

* Machine does not switch on. When you try to switch on the machine your HDD light flash and goes off.
* If machine switches on after several tries then there won't be any display.
* Machine shuts down after 10 to 15 mins of continues usage.
* 0175 CRC error occurs due to the above problem.

I have tried working on these issue as I could do lot of R&D on these planner boards. There seems to be a problem with DC-DC section on the planner board which is malfunctioning after continues load/usage. CRC error is generated as a result of sudden shitdown.

There are two ICs used for CPU VRM (Voltage regulator module) ie. ADP3421 and ADP3410. I have tried replacing both the chips along with three MOSFETs (IRF 7811). But the problem persist.

victor · S.F. Boss Joined: 07 Mar 2004 Posts: 2581 Location: Staff

Replacing the ADPs is not a 100% solution. I found often only the driver ADP3410 is fried or one of the IRFs is burnt.
In some cases the ICs are good but the circuit autocorrect functions (loop) is not working. Usually the current is messured through a 10ohm resistor which is interrupted. En fin, there are plenty of possible reasons for the circuit to not work.