Posts by Mr.Toast

Little update on this, Jens. I converted the A1200 to a hybrid PAL (preserving the NTSC system clock.). No behavioral changes to the issue.

I was able to acquire another A1200 and the card has been operating perfectly. I would gladly revisit this if your team has any ideas-or, even loan the board to your technical team for diagnostics. Clearly there is something defective with the A1200 that seems to have no impact on any other aspect of the system's performance-other than the ACA. (recall that it does not survive cold boot after flashing)

After spending some time with the ACA, it is an absolutely beautiful hardware upgrade. Just a shame we were not able to solve this specific issue.

Kind regards.

Tested unit-behavior same as described (hardware not found, works from rescue disk, cannot survive cold boot). The only note indicates that it is repaired (Rechnung RG21-1711).

I am guessing that the repair team could not identify the fault or CND?

Hi guys, my card arrived back. There doesn't appear to be a description of whether the unit has been repaired, replaced, or "could not duplicate". Is there any explanation about what happened?

Quote from Jens

Autores is not on by default, as there are quite a few monitors that don't like it. The latest update to the firmware and configtool introduce a resolutoin-switch with the "R" key during the test-screen to make autores available to more monitors, but that won't change anything here.

We also checked if a plain memory expansion has any influence on writing to the flash, but did not find anything. The one thing left to check is not too easy for us here in Europe, as I don't have a genuine NTSC board available for testing. The working hypothesis is that the higher base frequency and the "always start in NTSC, never see a PAL resolution" situation triggers a bug. I may be able to modify a board with a solder jumper and the right crystal, but work keeps piling up here since the start of the year (way too much administrative work). I fear it will at least take another week until I can take a short at such a modification and send it to Peter for testing (he's working in home office almost three hours away).

I sincerely appreciate the heroics. If it was practical (and it certainly isn't), I'd send you my A1200 and let your team have a working unit to do failure analysis on. I have a scope but no logic analyzer. If your team needs to ask me for measurements, I can be reached at the email provided.

Quote from Jens

Trying to get to the bottom of this, our technician was a bit too fast bringing the unit into "factory default" condition, meaning, the flash was overwritten. That means I have no way to find out what configuration you flashed that made the unit go "blind" after a power cycle.

Could it be that you've tried to save an autores-mode?

Sorry Jens-I missed the notifications on this.

Just for clarity, during my testing I had the exact same results with the memory expansion removed (completely stock).

If it was in autores, it was by default. I would do the recovery disk and boot off of the floppy or CF card. No attempt was made to configure the card other than defaults in most of my attempts. Configuring through all the available modes also did not change the results (hardware not found on cold boot).

Chris.

IC arrived a week ago but needed to clear the bench of another project.

It was a noble effort but replacing the flash has me back at the start. Boot to hardware not found. Reflash and everything works but does not survive cold boot. I'm going to put it under the microscope and give the board some tighter inspection-but, I think we're going to need to start the RMA process.

Thanks for giving this a shot, Jens.

Thank you, Jens. Appreciate the quality support!

My order number for this was 81634

I do not see any other unique identifiers on the email invoice received. The order date was August 8th if that helps.

No worries about the delays. Yes, the time difference presents some challenges!

Quote from Jens

Given the long distance and your obvious soldering skills, would you be willing to give a new flash chip a try? The flash chip is the only 8-pin chip next to the socket. If you feel confident enough to exchange that, I can ship out a new chip today, otherwise I'd just ask you to send the unit back to us after reading this article.

Yes, I have the skills and tools to swap the chip out. I can rework everything except BGAs.

Let's give this a shot.

OK, it was worth a shot. Recapped the PSU with ultra-low ESR Panasonics on the larger caps and the rest were Wurth for the smaller ones. Tested it without load and verified operational before putting it in the A1200. Once powering the A1200, I adjusted the 5V rail as perfectly as I can on an un-calibrated meter under load.

Exact same outcome: Rescue disk works, warm boot to gorgeous display. On cold boot, I get hardware not found,

Is it possible I just have a bad unit? I can only think of the flash RAM failing as to why reprogramming would temporarily work and not a power nuance.

I have an original 312503-01 (5V 4.5a) 110V supply. I could recap and tune the 5V rail under load.

Do you think this is worth the effort?

Unfortunately, I've run out of PSUs to try and survive a cold boot without having to use the rescue disk. 3 OEM ones and 2 Meanwell conversions. All support my A500 with accelerator and other hardware just fine (which I am aware is anecdotal).

Appreciate the attention. Anything else come to mind?

Well, maybe not so fast. It isn't surviving cold boots. Let me try some alternate PSUs.

SOLVED! Rescue disk worked. Glad this is resolved. Thanks, Jens.

After reading one of the other threads, I reflowed Lisa and still am observing the same problem.

Yes, USA.

Any test points or places I can put my scope that would help before sending this back?

Back from a great vacation & returning to this problem.

Tested with a variety (OEM) of PSUs and feeling pretty confident that is not the problem.

Buzzed all available solder points on Alice and matched to Amiga PCB Explorer on the top of the board with confidence that socket interface is good.

Verified LDO @ L4 5.04vdc in and 3.3vdc out

Verified XC95 is getting 3.3vdc

Verified DRAM is getting 3.3vdc

Zero signal on either VGA or HDMI end. Ran through OSSC for sanity.

I have not done further investigation beyond this.

Ahh, ripple. Got it. Have several good condition original PSUs I can test against. Thanks for pointing that out.

Sorry Jens. I'm out of pocket for a few weeks and won't be able to follow up until around 15 NOV.

I've stripped the A1200 down to the bone and running the machine off a Meanwell conversion PSU.

I've tested it with several re-seats but the config tool reports no hardware. No luck so far.

BTW- great appearance at AmiWest 2020 yesterday, Jens. Exciting to see your commitment to the Amiga future and the announcement of new Picasso96 drivers.