1088xld problems

[bfollowell]

29 minutes ago, chevymad said:

Also have better magnifying glasses coming. I think my vision is even crappier then it was when I built the XEL.

These are a must, especially if you're anything over about your mid-forties. I didn't always use them when soldering, but I definitely used them when going over solder joints. The few solder issues that I found, I would've never seen without my magnifying goggles.

 

[chevymad]

Ya, I turn 50 in a few weeks. I only have one eye due to childhood accident anyway, so no depth perception, but my upclose vision is really going to shit fast. 27 years as an automotive technician, my hands have little feeling and alot of shake. It's a challenge, but we all have challenges. Ordered a light up magnifying set, has replaceable lens's and you can wear glasses beneath them. We'll see, if I can see. LOL

[+Stephen]

9 hours ago, chevymad said:

Ya, I turn 50 in a few weeks. I only have one eye due to childhood accident anyway, so no depth perception, but my upclose vision is really going to shit fast. 27 years as an automotive technician, my hands have little feeling and alot of shake. It's a challenge, but we all have challenges. Ordered a light up magnifying set, has replaceable lens's and you can wear glasses beneath them. We'll see, if I can see. LOL

Sorry to hear of your issues.  I also have almost no depth perception as I was born with lazy eye.  Surgery corrected it, but the vision is super weak so I basically always just see out of my left eye.

11 hours ago, chevymad said:

One person came across as elitist and just rubbed me wrong. They probably didn't even mean it like that. Stephen thanks for the constructive criticism on the soldering. It definitely doesn't flow as easily as on the XEL. I'm going to try a few things and see if I can pick that up. Temp,solder, flux etc. The "electronic cleaner" I used also seems to dull/gray the solder. Just for curiousity, what temp is everyone using for the iron? This was bumped up a bit from what I used on the XEL.  Also have better magnifying glasses coming. I think my vision is even crappier then it was when I built the XEL. Even with stronger readers. Until then I won't be doing any more troubleshooting. Stepping back for a few days. I've been avoiding saying anything else here, to not make the hole deeper. The old saying If you can't say anything nice. 

I did also notice that these boards were more difficult to get the solder flowing.  I have a Weller soldering iron and use a very small tip.  I have the temp set to 650F and I also used Kester paste flux on both the top and bottom of the pcbs as well as using a small brush to apply it to the pins of the sockets.  When assembling the 1088s, I did the small things like resistors, diodes, and transistors first.  Then I did the sockets, holding them flat but only doing pins 1 and 40 (opposite corners).  That way, once I verified everything was correctly orientated and flat, I could rapidly flow all the remaining pins.  You can get into a really good rhythm this way and I found that by listening to the sizzle that the flux makes also helps stay consistent on the time on each pin.  I guess something I picked up as a welder - sound is often as important than vision on some things.  The worst part of all this, was cleaning the flux afterwards as my stuff is not water based but it works so well that you can watch solder flow uphill using this stuff, before you add so much that gravity takes over and it drips.

 

The only thing I can suggest at this point, and it is VERY tedious /boring to do, but you may want to check continuity from the pins on the top of the PCB to traces on the bottom of the PCB in the "trouble" areas.  I would not recommend re-flowing the entire board at this point, but when you have that good magnifier, do make sure that there is adequate solder that has flowed to the top of the PCB.

 

Good luck ongetting the board up and running.

[StickJock]

I'm not much older, and I recently realized that my close-up eyesight was shot when I was building up an SDrive-Max.  I had to keep using my phone camera zoomed in to see what I was doing!

 

I ended up ordering this ( 1.0X 1.5X 2.0X 2.5X 3.5X Adjustable 5 Lens Loupe LED Light Headband Magnifier Glass Lamp) from AliExpress:

 

Works great!  I can't wear it over my glasses, though.

[+DrVenkman]

I have a similar one. Also has interchangeable lenses but I *can* wear it over my glasses. 

[Simply_Graham]

It's just not fair, we all are getting older (58 in my case) along with our eyesight deteriating, and then they reduce the size of components even more !!

Surface mount components seem to be getting ever smaller, but even through-hole components can be small and fiddly, 1/8w resistors, 1N914's

I bought an Andonstar AD207 electronic microscope as a Christmas present to myself; which has it's own screen and a stand with two flexiable led lamps. Hand cordination with a fixed screen is a little odd and takes some getting used too, but does allow me to solder surface mount chips a tad easier, and more importantly a good inspection of any board after soldering.

https://www.aliexpress.com/item/4000251219592.html

Good luck with the repairs and fault finding

 

 

Edited April 30, 2020 by Simply_Graham

[+orpheuswaking]

1 hour ago, StickJock said:

I'm not much older, and I recently realized that my close-up eyesight was shot when I was building up an SDrive-Max.  I had to keep using my phone camera zoomed in to see what I was doing!

 

I ended up ordering this ( 1.0X 1.5X 2.0X 2.5X 3.5X Adjustable 5 Lens Loupe LED Light Headband Magnifier Glass Lamp) from AliExpress:

 

Works great!  I can't wear it over my glasses, though.

Same as I have, I can "kind" of get it over my glasses and it works well enough. Didn't really need it until this year. 

[chevymad]

That is very similar to what I've ordered. 

[AtariGeezer]

Even after my cataract surgery, I use 2.5x readers and a magnifying lens to see close up. I'll be 61 soon...

[bfollowell]

I've been pretty pleased with these. I find myself using them for more and more applications. They've definitely gotten a lot of use since I started doing repairs on my STE and building my XEL.

 

https://www.amazon.com/gp/product/B003UCODIA/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

 

[+DrVenkman]

35 minutes ago, bfollowell said:

I've been pretty pleased with these. I find myself using them for more and more applications. They've definitely gotten a lot of use since I started doing repairs on my STE and building my XEL.

 

https://www.amazon.com/gp/product/B003UCODIA/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

 

Those were the ones I was using until last summer, but when I bought them in 2015 they were only $8.04 per my order history. 

 

I replaced them with these, which are quite a bit more expensive but fit better, illuminate better, and have interchangeable lenses for those who need more magnification or if you need to do finer work on occastion.

 

https://www.amazon.com/Carson-MagniVisor-Head-Worn-Magnifier-CP-60/dp/B007CDJKM2

[chevymad]

These are what I've got coming.  https://www.amazon.com/gp/product/B075WR4M99/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1   I see we're all in the same boat here.  Now if I can steady the hands too... (cutting back on caffeine could help...)  Recently added a cheater lens to my welding helmet as well. It helps, but I'd still get laughed at by real welders.

[chevymad]

I may have found something. Pin #1 of RN2 is loose internally.. Actually came out of the rn. This appears to be associated with SIO. Explain the dead SIO? or would this have killed the whole board?

[+DrVenkman]

34 minutes ago, chevymad said:

I may have found something. Pin #1 of RN2 is loose internally.. Actually came out of the rn. This appears to be associated with SIO. Explain the dead SIO? or would this have killed the whole board?

Here's the relevant chunk of the schematic:

 

 

It's very unlikely you've killed the entire board, I think. I would desolder the resistor network from the board very, very carefully and replace it. Not sure what you have for desoldering, but even flux + solder wick and heat would work. A vacuum desoldering gun, or even one of those cheap plunger desoldering pumps, will work as well. Add some flux or fresh solder before you clear each pin and should come right out.  

[chevymad]

Was more questioning if this would just  kill SIO or make the board not boot? Way ahead of you on the desoldering.. I'll show what I'm up to pretty soon. 

Thanks

[chevymad]

So here's what I've gone and done. The wire repairs on the pia would have always bugged me, so I started over. New board in black.  

[chevymad]

Soldering is much better I think. Different temp, different flux, different solder.. different everything. The other solder I was using liked to sputter and make a mess. This radioshack stuff I had just flows in. Also some very messy radioshack flux.  Desoldering wasn't too bad, only the 40pin sockets can't really be saved(at least by me). RN2 came out, but when I went to reinstall pin 1 fell out. That's why i'm not sure if that was the problem, or just desoldering damage. I'm impressed with how tough the board actually is, I don't think I pulled a single via. I did blister 1 spot using hot hair... thought I was heating a different place. The board is pretty fragile to scratching, which is why I replaced it, scratched through a few PIA lines on the solder side.

 

Oh and the magnifying glasses work sweet! Wearing them and removing my contact.  So I need to order a couple components yet, rn2 and the ide header. Header didn't survive, basically any long component is very hard to save.

[Simply_Graham]

It's good that you were able to save all the components and reuse them, also gave you a chance to recheck any values as you went along, glad you like your new eyeball enhancers , Always nice to see what you’re doing properly.

The RN2 Pin two pulls the CLK-IN line High, it's obviously there for a reason, I'd guess to make sure the Negative pulses on the clock line are clean; it is responsible for gating the DATA-IN line with the correct timing, so could corrupt the SIO towards the Pokey.

It would be difficult to say for sure what effect this has without replicating. However it is the most likely cause you have found.

I guess you can see what happens with your new board, with RN2 missing its unlikely the SIO will function, as none of the lines are pulled High, but the rest of the XLD should be just fine.

Hope you get the other bits soon.

[+mytek]

SIO CLK-IN isn't used for many peripherals as far as I recall.  And I don't  believe either disk drives or SIO2PC utilize it. So in other words if it were left unconnected or not pulled up, you probably wouldn't experience any issue in normal SIO usage.

 

Edit: I just recalled that CLK-IN is used by the MIDI Controller chip for the MIDI clock, which isn't always required (depends upon the MIDI program in use). However in that usage a pull-up resistor is not required, since the MIDI Controller (PIC12F1572) will toggle it in a TTL fashion.

 

[+DrVenkman]

1 hour ago, mytek said:

SIO CLK-IN isn't used for many peripherals as far as I recall.  And I don't  believe either disk drives or SIO2PC utilize it. So in other words if it were left unconnected or not pulled up, you probably wouldn't experience any issue in normal SIO usage.

 

His initial post last night said pin 1 of RN2 was loose. That’s the pull-up resistor network for all the SIO lines, right? 

[chevymad]

Yes, it was pin 1, the main pin of the rn. I was getting ready to install it in the new board when that pin just fell out. Now the heat of removal could have loosened it, or maybe it explains why sio didn't work. BTW found no other solder blobs under any components. But I think that several places may not have gotten connection with both sides of the board? After removing and replacing the PIA socket there seemed to be a few disconnects on the top side. Working to fix that I ended up damaging a few more bottom side traces with my desoldering iron, precipitating my starting over.  When I desoldered the whole board, I went over all connections with the desoldering iron once, then hot air to get the component loose. Only the very long components had any issues, which basically meant replacing all 40pin sockets.

 

 

[chevymad]

Also finally got some ISO. Went to get more electronic cleaner and local stores were sold out.. Local grocery was sold out of commercial ISO, but had "fifths" from a washington distillery of 80%. I bought one, @$15!!! But I have plenty now lol

 

Haven't tried to fire up the board yet. Seemed to stay wet for a long time, so leaving it plenty of time to dry. The air duster stuff would rather freeze the moisture then blow it off. Is it safe to try the board without RN2? I also need to cycle my chip set back through the XEL and make sure there's no damage done after the PIA debacle.

[_The Doctor__]

You can build the resistor network from resistors old school and easy. Why would you try to run int without the RN, replicating the problems you already had?

[chevymad]

I haven't. Was implied possible somewhere above. And I'd thought about building a network, but need to go through my resistors to see if I have the proper value. Was curious if it was safe and if the board would simply function without sio. Anyway, the part is already on the way, just a matter of waiting some more.

[Simply_Graham]

Sorry seems I mis-led you,

Firstly I didn't read Chevymad's post properly , compounded by misinterpreting what I'd read. I was going by the 400/800 Hardware Manual . Page II-25 onwards and took this to be true of any data transfer.   Perhaps I should have read on a bit longer !

"Transmitted data changes when the output clock goes true. Received data is sampled when the input clock goes to zero."

I assumed  'true' was 'High' and 'Zero' was a 'Low' hence why they pulled up the CLK-IN line to a 'High'

Re Running the board without the RN2 in place, As the circuit is entirely digital in nature, then no damage should occur, none of the lines  affect the rest of the machine working, only the SIO would potentially fail.

Although I'm sure someone won't agree