I've had a better experience with NiCads funny enough... I've found that while they can cause a real wreck, they can also just be completely fine and not leak. The original one in my Compaq LTE Elite 4/75CX just charged right up and worked. The NiMH batteries seem to ALWAYS leak in comparison, and cause the same level of damage from my experience.
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AlphaTop/ECS Green Laptop documentation thread.
- Thread starter 3lectr1c
- Start date
itzyahmanjones
Member
- Joined
- Sep 30, 2013
- Messages
- 10
Funny how that works. Complete opposite here. I bought a zenith z-note 433lnc+ and it had a flat nicad and it just made a mess of the machine.
I bought a bunch of Green751 parts from @DeltaDon, so I should be able to fully document these now.
Included three motherboards and two sets of case pieces with most internal parts. Two DSTN screens which both work, and a TFT one that’s cracked.
One of the three boards was in an assembled unit, and that one did work. Unfortunately, just my luck, after taking it apart to swap the case pieces, I’m now having problems.
One of the two other motherboards did also POST, but the third is missing the DC jack for…some reason.
All three boards had soldered VARTA batteries on them, same as the G753. The battery on the board with the missing DC Jack was intact, but the batteries on the two working boards had both begun to leak. Both broke vias that appear to go into the parallel port, so they may have trouble. I removed all three batteries.
So, the problem. During my testing, BOTH working boards started experiencing the same fault. They’d make it some way through post, then reset, and would freeze up randomly at the post screen. It would never reach the point where I could actually get into BIOS. The fact that it’s happening on both boards now is weird - makes me think it’s something else. I doubt it’s the display assembly, as otherwise I should still hear it post beep every time. The only two things I can think of are the following:
1. Even though the CMOS batteries were leaking, perhaps these boards need something connected through there or they get cranky? I honestly doubt it - usually if a board is picky about CMOS batteries it will not work right when it’s dead, not just when you remove it.
2. On one test, I I realized I had one sub-board connected incorrectly (had one set of connector pins misaligned so whatever was going through those pins made was going to the wrong place). According to the documentation that came with the laptop, this board down converts 3.3V to 2.9 for the CPU. Perhaps doing this fried the CPU? I don’t have another compatible one to test with at the moment. The issue did crop up around the time after I did this, but I feel like it would have immediately fried the chip if it did cause damage.
Now it’s just stopped posting at all - the CPU gets warm, speakers respond to the volume keys on the keyboard (small pop sound when I click them), but no post. I’m sure I’ll figure it out eventually, with more parts swaps and stuff.
I’ve also ruled out the 2.9V board and the main DC/DC module, swapped both with spares with no change. AC adapter is fine.
Swapped the motherboard and it does post again now.
It’s still doing the bios reset thing though. I suspect it’s related to the fact that it’s reading the CPU as gibberish. The jumpers ARE set correctly for 75MHz. It read properly on my first test before I started messing with it.
It’s still doing the bios reset thing though. I suspect it’s related to the fact that it’s reading the CPU as gibberish. The jumpers ARE set correctly for 75MHz. It read properly on my first test before I started messing with it.
DeltaDon
Veteran Member
The second Green 751 which was in pieces had a failure tag from the Alphatop service center stating that it did this reset issue. I never worked on this model laptop and didn't even remember I had any of them in my stash of laptops until I started to dig into what I've got stored in my basement a few months ago. Maybe try resetting the BIOS by shorting removing the CMOS battery and shorting the BIOS chip power pin to ground for a minute or so. Other than that, maybe add a hard drive and see if needs a HDD to post and acts up if one isn't in place. Both just guesses.
Yeah, this:
It does say it “reboots in win95” so it doesn’t seem like the SAME issue, but it could be related. This isn’t that board anyway though.
CMOS battery has been removed. It had three same soldered varta that the G753s have, and it was leaking. It destroyed 5 vias going through the board, that seem to go to the parallel port. The other board that somewhat worked had only one bad via. The board from the warranty return unit had no leakage yet, but is missing the power jack.
I might want to try swapping the BIOS chip from the return board to the one that I’m using, just to see. I don’t have the proper chip puller to remove it though.
Behaves the same with a hard drive installed.
It does say it “reboots in win95” so it doesn’t seem like the SAME issue, but it could be related. This isn’t that board anyway though.
CMOS battery has been removed. It had three same soldered varta that the G753s have, and it was leaking. It destroyed 5 vias going through the board, that seem to go to the parallel port. The other board that somewhat worked had only one bad via. The board from the warranty return unit had no leakage yet, but is missing the power jack.
I might want to try swapping the BIOS chip from the return board to the one that I’m using, just to see. I don’t have the proper chip puller to remove it though.
Behaves the same with a hard drive installed.
JamieDoesStuff
Experienced Member
It it's a PLCC32 (or any PLCC for that matter, brown socket is how you identify it usually) just use a needle. Get it up from one side a bit, then do the diagonal to it, rinse and repeat. Just don't use a lot of force.
I'll give that a go tonight then. It is one of those sockets (I think). There are three IIRC, I'm assuming one or maybe more are BIOS related. I'll just swap them all if I can get them removed without damage.
I did some more testing last night, some of which I wrote about in the NOS G753 thread. Mainly, I ruled out the CPU as the problem. Works fine in my Green753. So that theory is dead.
Here's the current status on the three motherboards:
Board #1: The one that I'm currently using. This was the board that WAS working, from the Hyperdata branded unit that's photographed in this thread: https://forum.vcfed.org/index.php?threads/green-751-laptop.1245860/#post-1352811
This board is the one that's currently doing the BIOS loop issue. This one has 5 bad vias, caused by the CMOS battery leak. 4 of them definitely go to the parallel port, not sure about the 5th.
Board #2: DeltaDon found this board loose in unknown condition. This one started up on my first test, but had the same or similar BIOS loop issue that board #1 had. It shortly quit starting at all. The CMOS battery on this one leaked and broke one via, definitely going to the parallel port. I inspected it and found some bent pins on one of the chips on the bottom, I suspect the chipset. I gently bent them back but it did not resolve the no-post issue.
Board #3: From the warranty return issue that "resets in windows 95". Someone removed the power jack from it at some point so I can't test it. This one ALSO had bent pins on that same chip on the bottom. This one's in worse shape though, I'm not sure I can fix the pins. I'm going to try to use this one as a donor for the BIOS chips. This one's CMOS battery had not leaked so no corrosion damage.
Whether I get it fixed or not, I'm still glad I took the lot. It included all the original documentation and disks, so at the very least, I can get this model FULLY documented, the drivers and CPU switch settings archived, and that will hopefully help someone out in the future
I'll go push a site update soon with the pages on this one. Will be nice to have good quality photos of a pristine unit too, as it is in near mint condition with the case parts from the warranty return unit.
I'm gonna have to see if I can get my crappy inkjet printer/scanner combo unit working so I can try to scan the manual.
I did some more testing last night, some of which I wrote about in the NOS G753 thread. Mainly, I ruled out the CPU as the problem. Works fine in my Green753. So that theory is dead.
Here's the current status on the three motherboards:
Board #1: The one that I'm currently using. This was the board that WAS working, from the Hyperdata branded unit that's photographed in this thread: https://forum.vcfed.org/index.php?threads/green-751-laptop.1245860/#post-1352811
This board is the one that's currently doing the BIOS loop issue. This one has 5 bad vias, caused by the CMOS battery leak. 4 of them definitely go to the parallel port, not sure about the 5th.
Board #2: DeltaDon found this board loose in unknown condition. This one started up on my first test, but had the same or similar BIOS loop issue that board #1 had. It shortly quit starting at all. The CMOS battery on this one leaked and broke one via, definitely going to the parallel port. I inspected it and found some bent pins on one of the chips on the bottom, I suspect the chipset. I gently bent them back but it did not resolve the no-post issue.
Board #3: From the warranty return issue that "resets in windows 95". Someone removed the power jack from it at some point so I can't test it. This one ALSO had bent pins on that same chip on the bottom. This one's in worse shape though, I'm not sure I can fix the pins. I'm going to try to use this one as a donor for the BIOS chips. This one's CMOS battery had not leaked so no corrosion damage.
Whether I get it fixed or not, I'm still glad I took the lot. It included all the original documentation and disks, so at the very least, I can get this model FULLY documented, the drivers and CPU switch settings archived, and that will hopefully help someone out in the future
I'll go push a site update soon with the pages on this one. Will be nice to have good quality photos of a pristine unit too, as it is in near mint condition with the case parts from the warranty return unit.
I'm gonna have to see if I can get my crappy inkjet printer/scanner combo unit working so I can try to scan the manual.
Bonus preview: Here's what I believe to be the Green740, a 486-based Green laptop with an older looking design. This may or may not actually be the Green740, but it is an Alpha-Top laptop. Photo taken from the box. DeltaDon only had the box, none of the contents.
I swear, this thing looks familiar, but I don't know from where. I just think it's that it looks like so many other laptops. It resembles the original CTX EzBook, as well as some stuff that Jetta made.
I swear, this thing looks familiar, but I don't know from where. I just think it's that it looks like so many other laptops. It resembles the original CTX EzBook, as well as some stuff that Jetta made.
BIOS Chips swapped and well…
It looked like victory! But then…
Hmm…. Looks like that may have just been lucky. It is still reaching the full post, so we’ll have to see. I have a sad suspicion though that it’s going to get worse again. Odd sort of issue isn’t it!
It’s a newer BIOS revision as well, neat.
It looked like victory! But then…
Hmm…. Looks like that may have just been lucky. It is still reaching the full post, so we’ll have to see. I have a sad suspicion though that it’s going to get worse again. Odd sort of issue isn’t it!
It’s a newer BIOS revision as well, neat.
I found the problem. There’s an issue with the RTC.
Unsurprisingly, it slowly slipped back into the state from before. I noticed something though the last time I got it into BIOS, and that’s that the time and date display random gibberish characters, and the time rapidly jumps around. That combined with “Real time clock error” displaying ONLY when the CPU isn’t detected (notice from the photos) suggests I’ve found the culprit. Likely a bad crystal or the RTC chip itself is bad. Luckily I have a parts board!
It’s also developed a video issue, but that should hopefully be easy to sort. Probably a loose connection somewhere
Unsurprisingly, it slowly slipped back into the state from before. I noticed something though the last time I got it into BIOS, and that’s that the time and date display random gibberish characters, and the time rapidly jumps around. That combined with “Real time clock error” displaying ONLY when the CPU isn’t detected (notice from the photos) suggests I’ve found the culprit. Likely a bad crystal or the RTC chip itself is bad. Luckily I have a parts board!
It’s also developed a video issue, but that should hopefully be easy to sort. Probably a loose connection somewhere
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Crystal replaced with the one from the parts board, and as a good immediate sign, it posted properly first test. The real test will be if it continues to function fine at next restart, now in phase 2 of Windows 95’s setup.
I didn’t mention this previously, but it did indeed go back into the reset loop after it had to restart for phase 2 of setup.
I didn’t mention this previously, but it did indeed go back into the reset loop after it had to restart for phase 2 of setup.
Didn’t fix the issue but my soldering sucked so it could easily be that, I’ll redo it tomorrow. Also quit posting at all shortly after but it’s very likely related to my terrible soldering job. I’m really not great at replacing surface mount chips.
Progress is progress though.
Progress is progress though.
Reflowed it and got it in there good, and now it does start again! Still didn’t solve the RTC issue though. Honestly, the only idea I have left as to the cause is that it needs a battery in there. So, that’s the next step. I’m going to source a battery with the right cell config and then solder it in, see if that works.
At the very least, if I let it sit for a while, it will boot, once. Then it stays running and works.
LPT is very dead - triggers a nasty BSOD. Makes sense considering the bad vias related to it on this board. I do doubt it’s causing this issue though.
At the very least, if I let it sit for a while, it will boot, once. Then it stays running and works.
LPT is very dead - triggers a nasty BSOD. Makes sense considering the bad vias related to it on this board. I do doubt it’s causing this issue though.