Mr. Backup Z64 Self test error help

Hi everyone, first time poster/member here and I hope someone can help me out with my problem.
I have been looking all over the net for months regarding my error with my Z64 and I cannot find any info on how to fix it.
During the boot process my z64 sits there for about 5 seconds and then says "Test Chip Z64 Chip error"
Now I have a eprom programmer and have re flashed numerous z64 bios to see if that may rectify the error but to no avail.
I have even tried to look back at Dextrose.com archives which was the place to go for anything error related on all backup devices, but the site is defunct and you can only download bios's and cannot read any of the forum remedies.
I am guessing that something might be wrong with the Z64 board itself, and have looked over the board completely and cannot see anything burnt out, traces cut or cold solders.
I am hoping that someone here might have had a similar problem with this old backup unit and has a remedy.
I have seen people talk about ram errors and other problems with the screen only showing squares, but absolutely nothing on chip error :-(
Thanks and hope someone can help me out...

 

Have you verified the prom's contents after writing? Maybe it needs replacing.

 

Absolutely have @rso, everything checks out....I have a HW1 z64 on the way this week and I might try it's eprom in the faulty z64, but I don't think it will make a difference. Don't know till I try

 

Grab some RAM while you're at it in case Assembler is right. The HW1 only has half the RAM of the other two revisions, and I'm not sure if moving that to a later revision (even if just for testing) works (probably does, but having a spare doesn't hurt).

 

Thanks guys, The actual unit will let you know if the ram is bad during it's self test boot up
"Finally the system will self test its 128/256 M-bit DRAM memory. If the memory is damaged, it will display the ADDRESS ERROR or MEM ERROR (Memory Error) on the LCD Screen"
So that might not be the problem but worth a try

 

Just did what you suggested @ASSEMbler and reflowed all pin connections and tracked traces and cleaned with isopropyl, booted her up and still shows the same error..
I've just bought some more ram and should receive it in a few days, I'll test again when it arrives...
Personally I should after this just go looking for another one on here with a running 256 z64 and just keep this as a spare for parts, I've looked through the market on here and it's a bit dry atm.. Has anyone got a working z64 I could purchase? Might try the wtb in the future, but in the mean time I'll try a few more things if people have any ideas

 

Bit of an update, I received my 128 z64 today and did some swaps just to see if the error would go away.
Swapped over the bios chip - same error
Swapped over Ram - same error
Swapped over top casing just for giggles - same error
I compared both boards to each other side by side and the only difference between both boards were 3 onboard chips, everything else was exactly the same, except 1 chip of the 3 was from Ireland on the hw1 and the other was from Japan on hw2, that was the only difference.
I was wondering what was changed between hw1 and hw2 to make it 256mb on the board?. Lots of people and the maker say that you cannot upgrade the hw1 with no more detail.
Now I'm just waiting on the 32mb ram through the mail to pop into the hw2 to see if it gets rid of the Test Chip Z64 Chip error... Doubtful but worth a try...

 

I just remembered that the Z64's BIOS' source code is available. Sooo...

There's a couple of different places (at least five) that will end up showing your error message. Some do write some test patterns to various memory locations -> that'd support the RAM-gone-bad theory.

Afaict the 16M stick, even if working in a HW1, didn't work for you because the Z assumes there's always 32M of RAM on >=HW2; There's a message telling you to install more, but that doesn't happen until after you already see the 'Z64 CHIP ERROR' message on the LCD - also, it only gets sent to a debug port...

So here's hoping it was just a bad 32M RAM stick the first time, and an unexpectedly small one the second time, with both just happening to trigger the same message.

 

Thank you @rso , I hope that is true. I have 4x32MB 72Pin SIMM FAST Page Parity heading my way by next week so I hope at least one of those will fix my problem.
I tried the 32mb from the hw-2 in my hw-1 and the RAM worked in that !?!

 

Yeah it only checks and uses the lower 16MB. (The almighty internet says the HW1 can't ever use more than 16 so I guess there's probably not enough adress lines or sth like that? Dunno.) So if there's a hardware error with a memory cell above the 16M mark the HW1 won't care.

 

Funny you say that as there is also mixed reports on the net that the HW1 can take the 32mb and run the 256 games.
Being such an old unit now it's hard to find heaps of info, I remember there was heaps of info/mods on Dextrose back in the day but I was on there more for the V64.
The info from www.z64faq.tk you put up the other day on a similar thread is the most I have seen so far in one spot!

Open up your Z64 unit (doing so voids your warranty)..
If your using HW1, upgrade/downgrade to 1.09 then proceed.
If your using HW2, Chances are you already have 32megs of memory, if not, proceed..
Before touching anything, be sure to ground yourself, touch something made of metal and large...
Gently lift the Zip drive and you'll find the Motherboard underneath, there is a 72pin mem slot, replace the memory using standard 32meg edo 70ns ram.
Close up your unit, and all is well....=)

 

Chip Error means RAM is dead or not seated correctly, sometimes the slot breaks too.

 

Well I received my 4 sets of 32meg of ram today, tried them all and....... Same error on all sticks I don't know where to go from here other than buying another z64... The one thing I haven't done is rework the solder on the ram seat, I have gone over the pins with a magnifying glass and everything looks good and no pins bent, I could run a continuity test with my multi, but after that I'm stumped...

EDIT: Just did continuity test with and without ram and everything is fine there

 

I've changed the source code to show a different "chip error" message for each branch, instead of the same one. Hopefully that'll narrow it down. Mind you though, this is totally untested (basically I only know it compiles and the readme stated "errors: too many to list"), but since you have the knowledge & equipment to easily recover why not give it a shot. The .img goes to the prom as usual; this BIOS is supposed to have a hook that tries to load its main exe from the zip drive instead of the internal ram disk, so the z64.exe goes to a zip disk, cf card or whatever you have in there, in the root directory. You should then get a "Z64 CHIP ERR-n" with n=[1..5]. If you don't, tell me some other message you see when booting - I'll change that to sth else to make sure the correct z64.exe is loading.

 

Thank you very much for your help @rso I will try this out tomorrow as it is getting late here and will report back.
I am having to revert back to a zip disk to do this as I have not been able to get any sd or cf cards to work properly even with using gparted with ubuntu live and making it fat... the z64 just wont read the games on SD or CF card even with a 2 gig partition... Very strange but that is another matter, I just use an old pc with ide and put the games on zip and it works every time with 2.20 silverfox

 

OK @rso , I was able to put the z64.exe on a zip disk (It had 3 n64 games on it I don't think that would matter) and flashed the bios to the chip.
Booted it up and it gives the same original error as previous times, tried pressing down arrow at boot up as well and it sits blank then same boot chip error again. It does read off the zip drive when I switch on every time...

 

Sorry to hear that. Maybe that "base BIOS" didn't have those hooks I mentioned in yet? You could try reproducing the whole BIOS' build process to rebuild everything and see where that leads you, but for me that's above my pain treshold so I'll back out at this point. Best of luck.

 

Not a problem @rso, I really appreciate you help so far in this fiasco, I may just have to keep it as a spare parts machine.
Maybe you could chime in though on why I have a sd/cf card problem though when using an ide alltronics card reader, as stated before I used gparted to give a true fat16 partition, I am using either a 8 gig sd or a 16 gig CF and only using one 2gig partition on those cards and the reader just sits there and flashes like its reading but never loads and shows games on my hw1 screen!?!?.
I am using 2.20 silverfox and if i plug in my zip that actually works