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New pcb for 800XL? It exist.


ZuluGula

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4 hours ago, hueyjones70 said:

I have the RN resistors, they only have 7 pins. I guess I will have to examine a standard PCB to find out which holes are extra.


seems you have sourced the „bussed version“ of a resistor network, where all resistors have a common pin

in a 7 pin network you will have 6 resistors in „star“ or „bus“ configuration, the seventh pin is the common pin.

usually used as pull-up or pull-down for several signals

 

here you need the „isolated version“ of a resistor network, where all resistors are in parallel (like in the KiCAD schematic)

you will always have an even number of pins here - for 4 resistors you will have 8 pins

of course you could solder individual resistors, standing upright 

 

regards

Michael

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the resistors are not in parallel or series electrically within this network pack. They are isolated in a sip.

https://www.easytechjunkie.com/what-is-a-resistor-network.htm

 

you can have them in different packaging sip, dip, smd etc. or you can have them with no package at all and can see the resistors as components.

 

see resistor array.

 

check out near the bottom of each of these pages to look at a plethora of resistor networks/arrays and packaging

 

http://www.interfacebus.com/resistor-network-schematic-isolated-resistors-sip.html

Edited by _The Doctor__
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3 hours ago, hueyjones70 said:

The RNs that I have are the wrong strength anyway. They are 4.7K and are SIP that are for the 551 disk drive PCB.

It's up to you but I'd just get a bunch of 470 ohm resistors and solder them in.  Some XL's had the resistor packs and others had individual resistors.  I've noticed that individual resistors can be cheaper.

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  • 3 weeks later...

I finally got the board completely populated and it doesn't boot. I can't find any missing solder joints or solder bridges. It doesn't bother me so much that I spent the money for the board but I really hate that I expended the time and effort for nothing and I don't have the equipment nor the expertise to do a thorough job of trouble shooting.

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I wouldn't mind getting one of these, but the minimum order if five boards. So, with FedEx shipping, right now they average about $36 each. That's not too bad, but I don't want to be out $175 to get one board. If any of you want to go in together, I'd consider doing an order and re-shipping after arrival.

 

If anyone is interested, let me know. If we can get enough in to fill an order, I'll consider it.

 

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On 1/6/2023 at 4:39 PM, hueyjones70 said:

I finally got the board completely populated and it doesn't boot. I can't find any missing solder joints or solder bridges. It doesn't bother me so much that I spent the money for the board but I really hate that I expended the time and effort for nothing and I don't have the equipment nor the expertise to do a thorough job of trouble shooting.

What are the symptoms?  Is there any sign of video activity?  Can you use a cartridge and get sound?

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I have a black screen, no indication that there is a video signal. I tried to boot with Star Raiders and got nothing. Sys check doesn't give a video. I am going to check what I can using a multimeter and the guide from Sam's computer facts. I won't obsess over it because there just so many components that could be at fault. I know that it isn't any of the ICs because I checked each of them in another computer.

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Are you getting any sign of voltage passing through? Are the passive components used all new? And sockets look OK? 

 

Did you use an old delay line chip Incidentally?

 

Also are all the passive components, (resistors and caps), orientated the right way where it matters? 

Edited by Beeblebrox
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5 minutes ago, hueyjones70 said:

I have only one complaint about the PCB and that is that the holes for the power port and the monitor port were too small and I had to spend a considerable amount of time filing down the pins so they would fit.

good move filing pins instead of drilling board. I seen folks kill vias and other fun damage drilling as they weren't realizing there can be connections using the hole. +1

Edited by _The Doctor__
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1 hour ago, hueyjones70 said:

I have only one complaint about the PCB and that is that the holes for the power port and the monitor port were too small and I had to spend a considerable amount of time filing down the pins so they would fit.

I am sorry to hear about the hole sizes.  I will look into that right away.

Edited by reifsnyderb
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5 hours ago, hueyjones70 said:

I don't have a scope. Yes diodes are directional and the silk screening makes that easy to get right.

Meant diodes and caps (not resistors) earlier BTW. (Long day yesterday) ;)

 

If you don't have a scope as mentioned by others get a probe. They are dirt cheap and, alongside a multimeter have helped me diagnose some issues in the absence of a scope. 

 

So can you confirm voltage is passing through the board with a multimeter? 

Edited by Beeblebrox
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9 hours ago, hueyjones70 said:

I don't have a scope. Yes diodes are directional and the silk screening makes that easy to get right.

The USB oscilloscope/logic analyzer that connect to a PC don't have to be that expensive, but need a compatible PC for the display. They may not be as accurate/capable as a full size scope, but are better than a multimeter/logic probe.

https://www.amazon.com/s?k=oscilloscope+logic+analyzer&s=price-asc-rank&qid=1673268685&ref=sr_st_price-asc-rank&ds=v1%3AoEY36D2CS%2FNaJ39lfM%2Ba%2B3ZgDTKj2kFwtwAmTetxVHQ

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  • 4 months later...

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