Wallstreet PMU - Dead or Alive?

Question

Greetings all. I recently received a Wallstreet (1998 Model M4753) from my mother-in-law with a known history of instability. The laptop that is. Mother-in-law and I are both Mac fanatics. Long term goal is to upgrade hard drive, add wireless and pass onto college daughter. The Wallstreet booted up ok, appeared to be stable. Did add some more memory (256M) on the top slot, and upgraded to OSX 10.2.8. All applications worked ok. But the unit would not reawake properly and had to be physically powered down (plugs out, battery removed). But it would boot up ok. After reading thru all the glorious postings on the Wallstreet, I determined that the internal PRAM battery was defunct. Went to PBFixit, and after building up some courage dove into the disassembly of the Wallstreet and replaced the PRAM. Amazing how they fit all those components into such a small package.
But now I appear to have fallen backwards. Wallstreet will not power up (no chimes, dark screen, no CD drive activity). Have tried all the power management reset suggestions multiple times (press/hold the four reset keys (shift-fn-ctrl-power) for 30 seconds both with battery in/out, AC plugged in/out), but to no avail.
Current status: Wallstreet does not respond to power up button. Press/hold the four reset keys (shift-fn-ctrl-power) for 30 seconds results in sleep light (?) glowing green constantly. Another brief press of the four reset keys (shift-fn-ctrl-power) turns the green light off
Replacing the old PRAM has no effect on the response. Have I killed the PMU?
But on the upside, can now dissasemble the Wallstreet to a bucket of bokts and piece parts in my sleep!
Would appreciate any help/suggestions on what to try next.
Thanks and Happy New Year TJJ

Answer 1

TJJ,
Good work...persistence does pay.
If your 8GB partition is not available for OSX (grayed-out), reduce the size to 7.8GB or so.
Your Wallstreet should have a fan:
http://www.pbfixit.com/Guide/3.15.14.html
Apple did sell a "cacheless" 233MHz, but I am not sure how the Apple System Profiler reports it. If a Wallstreet has backside L2 cache that fails, I believe the Profiler reports it as "missing" or "0 K" or it is blank...just don't know. But there is no way to add L2 cache since it is soldered on the microprocessor card. You can, however, replace a cacheless 233MHz microprocessor card with a faster Wallstreet card but which card is compatible depends on your system bus speed. The first Wallstreet release had both a 66MHz or 83MHz bus speed; your Profiler will reveal its speed. Even a move to a 233MHz w/512K cache will give you a 70% speed boost over a cacheless 233 according to MacBench tests. The cards available are 233/250/266/292/300MHz but you must know your bus speed.
As an example, you can buy a used 250MHz w/1MB for $50 at this site; check out all the other speeds.
http://www.pbfixit.com/cart/customer/product.php?productid=168&cat=&page=1