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heyloo :)

PPCMLA PowerPC 17 posts Apr 25, 2007 to Apr 27, 2007
Spent today trying to get my SE/30 working, and I did get it to boot once!!

It's always had the classic horizontal stripes SimasiMac, without any chimes. I replaced all the caps, without any luck.

I was poking at signals today and found that the reset switch is bad--it was around 500 ohms between the terminals without the button being pushed, which must have been causing problems. I removed R5 to disable the reset button, after that it booted to the flashing question mark! I even got a startup chime when I plugged in a speaker.

NkzZBbtl.jpg.ab8dac48ac67e9b73dd47ba137b5c80a.jpg


I then turned it off and wired in Q3 (a 2N3904 for ADB, it had corroded off). After that it won't boot again, it's having the same symptoms:

RESET* is acting odd. Sometimes after powering on it's around 0.7V, and sometimes will goes up to 5V after a few minutes. No change after it goes high though.

Once RESET* goes to 5V, VSYNC goes to 60 Hz.

Also the 5 PALs (UE6, UE7, UG6, UG7, UI6) are all pretty warm after a minute or two. I can keep my finger on them, but they're much warmer than the 68K or other chips.

ROM CS is high, doesn't change. ROM address lines also don't change. OVERLAY is also high.

CPU is socketed but I haven't tried pulling it out. The 16 MHz clock is running also.

Anyone have any ideas for what to try next? I tried pulling the sound chip high (2K between Sony sound UB11 pin 7-15) but no change.

Well with the 68kMLA gone to the big Trash can in the sky for the time being i thought it was about time i joined here. Smile As you may guess, yes i am LCGuy, the same LCGuy that was on the 68kMLA. I can see quite a few familiar faces here already, so i already feel at home, even if it is not the 68kMLA. Smile
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"I mean, how hard can it be?" - Jeremy Clarkson

The Infamous LCGuy - Now back with Amazing Working iMac Action™!
Hey LCGuy! Welcome to the PPCMLA! Hopefully the 68kMLA isn't totally toasted, and will be back up eventually. If not they can always start over new!
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iMac G5, Powerbook G3/333, Beige G3MT, PM 6200CD, RS/6000
After the "fix" is done, you can spray the reset button with contact cleaner as you press and depress the button, spraying along the button and its frame to clean it out and maybe that will solve the switch problem. Then you can restore R5 back into place.

TechKnight, which Sound Chip? There are two Sony Sound Chips by the Reset Switch as I see on my SE/30 board: UB10 and UB11. Unless you mean UE10 further down the board which is made by Hitachi.

Thanks for the welcome, John. Smile Even if the forums do go back up, it wouldn't make it suck any less that we may lose 3 years worth of archives. Sad
_________________
"I mean, how hard can it be?" - Jeremy Clarkson

The Infamous LCGuy - Now back with Amazing Working iMac Action™!
Hiya Very Happy And welcome!

Nah, they'll get it back up.
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PPC Macs:
  • Power Macintosh G4
  • B&W Power Macintosh G4
  • Power Macintosh 6500/225
Well, of course. But wether or not the posts are threre, well, thats another matter...
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iMac G5, Powerbook G3/333, Beige G3MT, PM 6200CD, RS/6000
They'll definately get it back up. When, i don't know, but they will. Anyway, i'm not sure if i'm supposed to spill the beans on what happened exactly, so i won't say much, but basically what happened is that the server that the 68kMLA was hosted on took a complete ****, and the tools at iPowerweb didn't make any backups. :-/

Thanks for the welcomes, btw Very Happy
_________________
"I mean, how hard can it be?" - Jeremy Clarkson

The Infamous LCGuy - Now back with Amazing Working iMac Action™!
Heyloo to you too, LCGuy, and welcome aboard. Very Happy
Thank you. Smile Dumb question, but i don't recall seeing you on the 68kMLA. If you weren't on the 68kMLA, don't worry, but i'm just wondering who you were there if you were on the 68kMLA. Smile
_________________
"I mean, how hard can it be?" - Jeremy Clarkson

The Infamous LCGuy - Now back with Amazing Working iMac Action™!
I pulled out UB11, cleaned it and the board off, put it in a socket and back on the board. Still wouldn't boot  :(

But after a few more power cycles, I got it to boot again! Then went to wire Q3 on, and stripes again  :(

And most of the time I get stripes, RESET* is at 5V. As long as RESET* is high, does that mean the sound chip isn't causing the problem?

Hey LCGuy, glad to see you on a forum. Razz

I think it's somewhat ironic that the 68kMLA took a dump at this time - it was both times when I was at almost 5000 posts. Razz

I honestly wouldn't mind too much if they started over, but I wouldn't be so offended if they were able to find a recent enough backup. I don't know if I'd want to start from like, 3 months ago or whatever though.
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[Insert Cool Signature here!]
Welcome, Cory!

Peace,
Drew
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Power to the PowerPC!
It's just a 2N3904 wired to (what I'm pretty sure are) the right places. It's never booted with that installed, but it's failed to boot many times without it as well.

I did the same thing last night after it booted--hooked up Q3, saw it didn't boot, disconnected Q3, and it still wouldn't boot.

So it's not proven good, but also not proven bad

Welcome Cory, and congrats on your new mod-ness! Smile
_________________
"I mean, how hard can it be?" - Jeremy Clarkson

The Infamous LCGuy - Now back with Amazing Working iMac Action™!
Oooh - thank you. Smile

I suppose I've been signed up for this forum forever, and haven't ever really posted. Razz

I do like these Mac OS Dude emoticons too. Very Happy
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[Insert Cool Signature here!]
Hmm how would I check that? I can use a scope and try to see how long it takes to rise vs. +5V.

Would the machine boot without UB11 installed at all? I see RP7 pulls it up to 5V, is UB11 actually driving it high as well?

I don't have any other sound chips to swap in there, but I could wire UB10's RESET line to the system reset line (as well as the TEST* it's already hooked up to)

Some times I hate custom parts... After googling about, many sites want you to sign up to their service and then you have to request a price quote for the chip.

The only site I found that did gave  price is in China, and they only sell it in Lots of 10 for about $60, or $6 a chip. In my mind, cheap for a single custom made chip, but I don't need 10. Also its coming from China, so delivery to the USA is between 3 to 6 weeks minimum. I do not know about the rest of the globe. Maybe you can talk to them about selling you just a pair? Here is it's URL:

http://www.aliexpress.com/w/wholesale-3430045b.html

The other sites that want you to sign up and request a pice quote are here:

http://www.hobid.com/electronic-component/3430045B/

http://octopart.com/3430045b-sony-15668215

I can't answer that myself as i don't actually know, but next time i see either of them, i'll ask cinemafia or Tom Levens.
_________________
"I mean, how hard can it be?" - Jeremy Clarkson

The Infamous LCGuy - Now back with Amazing Working iMac Action™!
I really hope that there's some way to save the PMs at least... Hopefully the posts can be saved too, but it's sounding like that's less and less likely...
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PPC Macs:
  • Power Macintosh G4
  • B&W Power Macintosh G4
  • Power Macintosh 6500/225
Yeah...i hope so too...there's some stuff i didn't get which makes me cranky!
_________________
"I mean, how hard can it be?" - Jeremy Clarkson

The Infamous LCGuy - Now back with Amazing Working iMac Action™!
I tried disconnecting RESET from UB11 and wired UB10s RESET line to the hole instead, still shows at 5V but no change. I'm starting to think maybe there's a problem with the trace carrying reset to the sound chip, I'll try a separate wire for it

Tried the extra wire for RESET, still no change. RESET is at 4.82V when the system is on. I also disconnected Q3 again, still no change. The SENSE pin to the sound chips is also +5V like it should be.

Thanks for your help techknight, do you have any suggestions to try next?

I've looked at the schematics (Sound and Serial - File P7 of those you gave me). The only thing that caught my eye as C16 ( .1µf) on the bottom of the board. Its parallel to the Reset Button (both to ground). So if C16 is shorted out then it would hold the reset down. It would also look like the reset button is shorted out.

Have you tried removing C16? And then test the reset button.

After tracing more signals (and not finding anything out of order), I think the problem is a dodgy connection at the CPU or maybe ROM SIMM.

The last time it didn't work, I gave the CPU and ROM a good push and it started working. I have a socketed CPU and I've never pulled it out, if the problem gets worse I might try that.

The next weird problem: for some reason this SE/30 has an 800k floppy drive (MFD-51W-03)! It also has a Miniscribe 8425SA that isn't spinning up, I need to put that in an external enclosure and see if I can get it to spin. The HD has a real old production date (1986) for an SE/30, almost like this machine had SE drives swapped into it.

At least with the Floppy Drive, it could have been replaced long ago when the original owner (?) took a pair of pliers to a stuck floppy disk and ripped out the heads. Similarly with the had drive, it may have been replaced too. I remember Miniscribe Drives being used in hard drive enclosures for the Plus,  not on an SE or SE30.

As or the ROM & CPU, this would be one of the few times I say to spray/brush with flux and then reheat the solder joints, while pressing down on the socket.

mp.ls