Thursday, January 22, 2009

Maxim1532a - Maxim1987 issue on Toshiba M35 Motherboards

My fix for the non-responsive Toshiba M35 continues to produce happy readers. I'm glad for that.
This morning I got a question:

I had reassemble my m35x-s329 and found that the power chip using Maxim-max1532a ETL instead of max1987. Can I just replace by max1987 which is easier to found this specific on the market..

ID motherboard K000019630.

Unfortunately for all of us Maxim/Dallas Semiconductor left us out in the dark on their MAX1987 power driver chip, so we can only derive conclusions of its functionality/characteristics. On the other hand, there is sufficient info on the MAX1532a, and as I understood the document, it is a power driver, used on P4 and P4 Mobile CPUs, produced sometime 2003, provides 1, 1.2, 3.3, 5V, and also has "high voltage" module for the more demanding components. WOW. That is something we didn't really know. Thanks Maxim/Dallas. In my search for more info, i also found one document that mentions both the Max1532 and the Max1987. But that's basically all it does. It mentions them.

So, let's get back to the initial question: Can the Maxim1532 be used instead the Maxim1987?
The logic may suggest that these two bunnies are interchangeable. But that's only guesswork, a hunt in the dark. The input and output voltages are the same: you get the same 18V DC, same battery, same (?) CPU, RAM, Chipset etc. so judging by the "black box" approach, if the same stuff enters both black boxes, and the same stuff comes out on the other end of both boxes, chanses are the black boxes are identical. For an old laptop, I'd say heck, try it! If it burns, it wont be a big deal as its a cheap thing anyways. But I'd not do it if it was used in a pacemaker, so I offer no warranties on this advice.
If you DO however choose to test the compatibility the hard way, I suggest removing the modem board, RAM, CPU, HDD, DVD... anything that is removable, so if things to get hot, you wouldn't waste the peripherals and the CPU/RAM. Attach only the switch board and the CPU fan, to get a feedback if it spins up. Then, plug in the CPU and try again. If it works, great. If not... no big loss as you already had a malfunctioning power driver.
In case if you want to purchase it, I found this site where you can order it.
Whatever happens, let the community know.
Thanks again to all of you who read, fix and share experiences. By the way, if you do visit this blog often, scribble a note on the other posts as well, just to know that somebody out there other than Google sees my stuff.

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Jim Horn said...

Igor, if you'd like a copy of Maxim's spec sheets for the MAX1987 and MAX1532, please let me know. No, they're not interchangeable as they don't have the same number of pins. The 1987 appears to be a superset of the 1532.

Thanks again!

Jim Horn, Bingen, Washington USA

Anonymous said...

jim i would like the specs can you email them to me

Denis said...

Hi Jim, could you send me the datasheets for the MAX1987 and MAX1532 too, please?
My mail is

Thank you in advance

eladb said...

Hey Jim,

could you please also send me the datasheets for the MAX1987 & 1532 ?
My email:

Many thanks...Dale