derkom's doings

[derkom]

Damn, I bet that combined chip is an arse to check with the pins in such close proximity.

Not too bad with a fine probe and a good magnifier.

I think as you say you have more than one problem here, and that video one is a pain. Have you checked the clocks at the Shifter? I know the DIP type should have 32Mhz on pin 2 and 16 Mhz on pin 39, but don't have a pinout for PLCC type (Yet!)

It certainly doesn't look good if after a while the sync signals stop coming from the GLUE, that chip will be a bit of a bugger to swap out.

Really need to find out what inputs the GLUE needs to generate the sync signals, but if they are generated internally, it's not looking good for the GLUE.

Clocks on the shifter are all fine. I don't have a pinout either, but the schematics have the pin numbers, so good enough.

I agree that it's not sounding great for the GLUE. I kind of don't mind if I need to replace it, because I would like to get some more SMT practice, and the chip itself is only £5 on eBay. Just the same, I'd prefer that it not be broken.

[derkom]

Since I've got the TOS switcher in there, I figured it might be a little more useful to be booting 2.06 instead of 1.62, so that I could see (or not) the Atari logo on boot, so I disabled the UBE switch and sure enough, Atari logo comes up fine in the moments the system will run, so really everything seems to be perfectly fine, until it isn't.

[derkom]

Tried a couple of things, and got some possibly interesting data.

With the system cold enough to produce sync briefly, I let it do so, and then right after it stopped, I sprayed a little bit of canned air propellant onto the glue (I should really be using cold spray for this, but I don't have any) and sync returned, although for only a fraction of a second. Then I left a cold pack sitting on the glue (powered down) for about 15 minutes and turned it back on. Under normal circumstances, this would buy me about two seconds of runtime, but I got about five. I'll do a little more data gathering, but it's looking like something inside the glue is heating up fast and failing. (Not to the point of making the glue package warm though.)

[rubber_jonnie]

I agree that it's not sounding great for the GLUE. I kind of don't mind if I need to replace it, because I would like to get some more SMT practice, and the chip itself is only £5 on eBay. Just the same, I'd prefer that it not be broken.

Yeah, I know that feeling after my Mega4 kept dying time after time.

[rubber_jonnie]

Tried a couple of things, and got some possibly interesting data.

With the system cold enough to produce sync briefly, I let it do so, and then right after it stopped, I sprayed a little bit of canned air propellant onto the glue (I should really be using cold spray for this, but I don't have any) and sync returned, although for only a fraction of a second. Then I left a cold pack sitting on the glue (powered down) for about 15 minutes and turned it back on. Under normal circumstances, this would buy me about two seconds of runtime, but I got about five. I'll do a little more data gathering, but it's looking like something inside the glue is heating up fast and failing. (Not to the point of making the glue package warm though.)

All roads seem to lead to GLUE, looks like you may be getting that SMT practice after all

[PhilC]

I agree with RJ, sounds like that multi pinned monster is to blame.

[derkom]

All roads seem to lead to GLUE, looks like you may be getting that SMT practice after all

I agree with RJ, sounds like that multi pinned monster is to blame.

I got the replacement chip this week and installed it today, and I'm pleased to report success. The STE is back in business, and currently running GEMBench to verify stability. I have very little SMT experience, so the prospect of a 144 pin SOIC was kind of scary, but it worked out really well. This was the first time I got drag soldering to actually work, and once I got the hang of the right angle, touch, and pace, it was smooth sailing.

C302183-002.jpg (120.42 KiB) Viewed 3085 times

Very pleased with those results. I'm not going to start the accelerator install tonight (famous last words), but now that the STE is up and running, I'll try to get the accelerator done over the weekend.


Oh, and @exxos, here's another fun one for your gallery....

IMG_20200605_173729.jpg (66.14 KiB) Viewed 3085 times

[exxos]

[PhilC]

Nice work @derkom

[rubber_jonnie]

Good job sir