T42- black screen- bad motherboard or bad memory?

[helicopter]

I have a T42 with the ATI 9600 GPU and the long fan. The machine won't boot and produces a black screen with the "Z" light on. I tried removing the HDD and booting from a USB floppy, which didn't work. I tried removing the DIMM from the bottom slot, which didn't work. I tried reseating the DIMM under the keyboard but can't swap it out because I don't have another stick. I can hear the fan and the HDD spin for a second when I first power on. Also, if I put a boot DVD in the DVD drive, it will spin for a few seconds. I get no memory beeps or beeps of any kind. How do I know if this is a memory problem or a motherboard problem?

If it's the motherboard, I'm confused about which one I should buy. There are many listed for the 15" T42 in the hardware manual, it uses different ATI numbers (not 9600). Also, on ebay, I see sellers with the FRU 27K9985, which isn't listed in the hardware manual. Is it the same one?

Thanks in advance. This is the third time in 10 years the motherboard (possibly) has failed on this machine. Not a happy TP owner!

[MrMaguire]

Most likely the GPU has cracked solder joints. It can be fixed via reflowing the solder using heat, or removing the chip completely and applying new solder.

Any T4x motherboard should work, if I'm not mistaken. Even an R5x motherboard will work, which is good since those have Intel graphics, and don't typically suffer with bad solder joints. Though, if your T42 has the high-res display, I think Intel graphics won't be sufficient to drive it. As in, it won't actually work.

[RealBlackStuff]

If you go the T43/R52 way, you also need a different CPU, different RAM and (if I remember correctly) a different PCMCIA cage.
The rest will still fit.
All other T40/1/2 or R50/1 mobos will fit identical to your current mobo.

[rkawakami]

Getting back to one of your original questions:

I get no memory beeps or beeps of any kind. How do I know if this is a memory problem or a motherboard problem?

Assuming that your speakers are enabled and still operating, removal of ALL memory modules from the system should yield a 1-3-3-1 beep code (and a black screen) upon power up. If you don't get any beeping, that usually points to a bad motherboard. Installing any memory at that point is useless because the system has already failed a basic test. You also don't know if the module(s) are defective unless you can test them in another compatible machine.

Assuming that you DO get the beep code with no memory (i.e., the motherboard is functional enough to detect a bad memory condition) AND if you get the same code when installing ONE memory module, then that module is bad (or the slot that it's installed in is bad). That's why you should move that module to the other slot and repeat the power-up before declaring the module bad.

[ajkula66]

If it's the motherboard, I'm confused about which one I should buy. There are many listed for the 15" T42 in the hardware manual, it uses different ATI numbers (not 9600). Also, on ebay, I see sellers with the FRU 27K9985, which isn't listed in the hardware manual. Is it the same one?

Motherboards are the same for 14" and 15" machines. You'll see a *lot* of FRUs that are not found in the HMM. For a fairly complete list, see here:

http://www.theboardroom.info/ibm_list.htm

As Ray stated, the board that doesn't beep when all the RAM is removed is likely beyond repair.

Having said that, have you tried this old trick:

Remove the battery, hard and media drives, unplug the AC adapter.

Press the "power" button ten times in a row, holding it down for ten seconds each time and thirty seconds the last time around.

Plug the adapter - but nothing else - back in and try to power on.

Good luck.

[helicopter]

Good advice all around.

I removed all the DIMMS and didn't get the 1-3-3-1 beep code (and the speakers had been enabled/functional when the T42 worked). I also tried the 10x on/off trick with the power button. Unfortunately that didn't work.

Thanks for the link to the boardroom. I recognized that Toucan with the Guinness!

And RealBlackStuff: thanks for the translation of what ATI M6, M7, etc. mean. I don't think the IBM HMM ever mentions that.

So now I will ponder whether I will buy a motherboard or not.