A4000 won't boot, help!?

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WhyreByter

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So... In my other threads I've chronicled my efforts to replace the caps on my a4K. Finished up last night, hooked up the essentials and powered her up, and no go. So, I'm opening a thread here in the hopes of catching people in the "troubleshooting" section. :)


Here's what's what:
  • It worked OK before I started, albeit with very leaky caps
  • Inspection after the caps were off looked OK
  • New cap installation has been quadruple-checked for value/direction/alignment
  • Only things hooked up are a520 into my TV, power supply, RAM and 3640 (but have tried it with HDD/keyboard/mouse as well)
  • What I get is a black screen with no drive activity for a long time (~ 1 minute or more), after which I get a black/grey "moire" pattern on the screen for a split second, and then it goes black again, and my TV loses sync
  • After the screen goes off after the pattern, using the CTRL-A-A causes the cycle to restart
  • Using the two-mouse-button startup has the same result
  • I've tried it without any SIMMs in, with the same result
  • I've checked the +5/+12/-12 voltages at various points, and they're all +4.9x/+11.9x/-11.9x
  • I've done a thorough visual of the areas that I worked on, and everything looks OK. Plus, the bulk of the work was done in the audio section, or some in the video, which, even if those died shouldn't keep the machine from running the HDD during startup
  • I checked the cpu connector, and did notice a couple of pins that looked lightly oxidized, so cleaned them with alcohol, to no avail
Cosmos suggested (on another thread) that if pulling the chip ram didn't cause a green screen on startup that I should replace U891. I don't have a spare one of those, so would like to find some other troubleshooting steps while I find one of those.

:sos:

Help? Thanks...!
WhyreByter
 
Have you got a floppy drive attached and powered etc? I'm not if the A4000 would boot without one
 
IT LIVES!!!

Notes to self:
  1. Replacing U177 when the RTC doesn't work, and the legs are green and fuzzy: good plan
  2. Using a new solder paste that you're not familiar with and leaving a little solder blob on the underside of the chip: not a good plan
  3. Yes, you can run an A4000 with U177 completely removed (and no little solder blobs present)
  4. Stop by Fry's tomorrow and pick up a new fan; the one that's in the power supply sounds like a jet engine
  5. The boot delay on these things can only exist to make people go crazy (how can you disable that, anyway!?)
Now, everything on it works (full 16MB of fast ram, 2 MB of chip ram, audio sounds great, video looks great, RTC is even recognized now, though I need to put a battery in it).

I need to relax for the rest of the evening; today has been a bit tense with Amiga troubleshooting and other things! Tomorrow I'll be working on it some more, and will post some updated pictures in the other thread.

Thanks everyone!

Cheers!
WhyreByter
 
WhyreByter said:
The boot delay on these things can only exist to make people go crazy (how can you disable that, anyway!?)
Click to expand...

It's the timeout on the internal IDE port. Either plug an IDE disk on it, or if you're not going to use the on-board IDE, get an IDE terminator from amigakit.com :)
 
I've got a hdd on it already, which makes it shorter, but it's still along the lines of 30 seconds. Not sure what will happen when I add my CDROM to the chain, though.

Right now, I'm just happy it works again... :)

Thanks!
WhyreByter
 
Good work!

I still have yet to use solder paste :D . I need to in order to repair my 4000 as I have remove U177 and a few other bits like that ..

*gulp*
 
WhyreByter said:
I've got a hdd on it already, which makes it shorter, but it's still along the lines of 30 seconds. Not sure what will happen when I add my CDROM to the chain, though.

Right now, I'm just happy it works again... :)

Thanks!
WhyreByter
Click to expand...

Make sure the Hard drive is set to Master. It will boot from a Slave set drive eventually. So, be sure you set HD to Master & CDROM to Slave or you will have problems.

Kin
 
Thanks. I had a HDD on it, and it was still taking a long-ish time. When I added the CDRom to the chain, it boots instantly. :thumbsup:

--WhyreByter

---------- Post added at 19:35 ---------- Previous post was at 19:34 ----------

@chiark - Paste is awesome, except when it isn't. ;) Learn to use it, it's a real timesaver. But find a brand/formula that you're comfortable with, and stick with it. Practice/consistency is the key here...

Cheers!
WhyreByter
 
Great news, I knew you would get it up and running in no time!
 
WhyreByter said:
Thanks. I had a HDD on it, and it was still taking a long-ish time. When I added the CDRom to the chain, it boots instantly. :thumbsup:

--WhyreByter

---------- Post added at 19:35 ---------- Previous post was at 19:34 ----------

@chiark - Paste is awesome, except when it isn't. ;) Learn to use it, it's a real timesaver. But find a brand/formula that you're comfortable with, and stick with it. Practice/consistency is the key here...

Cheers!
WhyreByter
Click to expand...

Did you check if the Hard Drive was set to Master & the CDROM to Slave?

Kin
 
WhyreByter said:
IT LIVES!!!

Notes to self:
  1. Replacing U177 when the RTC doesn't work, and the legs are green and fuzzy: good plan
  2. Using a new solder paste that you're not familiar with and leaving a little solder blob on the underside of the chip: not a good plan
  3. Yes, you can run an A4000 with U177 completely removed (and no little solder blobs present)
  4. Stop by Fry's tomorrow and pick up a new fan; the one that's in the power supply sounds like a jet engine
  5. The boot delay on these things can only exist to make people go crazy (how can you disable that, anyway!?)
Now, everything on it works (full 16MB of fast ram, 2 MB of chip ram, audio sounds great, video looks great, RTC is even recognized now, though I need to put a battery in it).

I need to relax for the rest of the evening; today has been a bit tense with Amiga troubleshooting and other things! Tomorrow I'll be working on it some more, and will post some updated pictures in the other thread.

Thanks everyone!

Cheers!
WhyreByter
Click to expand...

He he, thought this was deja vu, then realised I was on another site, ;).

Theose latching chips are buggers, as they are connected to the Clock chip and system roms.
 
@FOL - Yeah, thanks. I posted the same message(s) on amibay and abime, just to get max coverage, because I was starting to get a bit stressed out over it. :)

Thanks for your help on the other board...

Yeah, I had inadvertently shorted a couple of the address lines together, which effectively takes down the whole computer.

Thanks!
WhyreByter
 
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