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Odd problem with XT-IDE Rev 0 in a 5150

geneb

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Aug 19, 2003
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503
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Graham, WA USA
I've been working on my 5150 today and I've got it booting DOS, but when I try to add the XT-IDE card I built a few years ago, _nothing_ happens.

The power supply starts, but I don't get a cursor on the display I've checked the board and I don't see any solder bridges.

The PC has 256k on the board, no additional RAM is installed. I've got an MDA card in slot 1, the XT-IDE in slot 2 and the floppy controller in slot 5.

Any suggestions?

thnx!

g.
 

modem7

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Sounds like the PSU is being shorted (which does not always stop the PSU fan from turning).

* If card is bracketless, ensure that the card is inserted the correct way (chips towards power supply).
* Verify that all ICs are orientated in the correct way.
* Verify that each chip is the correct type for the position (e.g. 74LS04 in socket U5).
* Remove all ICs from the card, and then see if the 5150 powers up with the card inserted.
 

geneb

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Graham, WA USA
It is the first time the card has been installed.

Besides solder bridges, any suggestions on what to look for? A cursor exam under a 3 diopter didn't show any bridges...

g.
 

geneb

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I pulled all the parts and the machine boots. I put in the first '688 (closest to the backplane plate) and it throws a memory error and a pile of ROM errors. I put the '245 in and the machine won't boot - no hardware cursor.

Is the '245 bad, or is something else going on?

I do know that the board was hell soldering up. I had a very difficult time getting the solder to flow on the pads - I've done a lot of assembly & rework and I've NEVER had the kinds of problems I had with this board.

g.
 

modem7

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I pulled all the parts and the machine boots. I put in the first '688 (closest to the backplane plate) and it throws a memory error and a pile of ROM errors. I put the '245 in and the machine won't boot - no hardware cursor. Is the '245 bad, or is something else going on?
You don't have a spare '245 ?
 

Malc

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Leave all sockets empty except for U9 and U10 and jumper jp1 and jp2, does the machine boot and display the xtide bios screen and can you flash the 28C64 chip ? if not I'd double check the solder joints, Basically all you need populated on the board is just U9 / C9 / RR2 / SW1 / U10 / C10 / JP1 and JP2 to get the xtide-bios screen up, make sure that works first and then populate the other sockets, You could also have a bad 245 chip.

I pulled all the parts and the machine boots. I put in the first '688 (closest to the backplane plate) and it throws a memory error and a pile of ROM errors.
g.
 

geneb

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Aug 19, 2003
Messages
503
Location
Graham, WA USA
Ok, now I get no errors out of it at all with just U9 and U10 installed and no XT-IDE sign on messages.

ANY '245 will prevent the machine from booting. :(

I'm out of guesses at this point. The poor solder flow on all the joints might be a contributing factor though.

Do the current XT-IDE boards use the same parts?

g.
 

pearce_jj

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UK
Follow back the /OE and DIR lines on that 245 - presumably it's driving the bus continuously either because of a short on either of those or bad address decoding logic (520/521/688s).

FWIW, I too had a hard time with the V1 PCBs, achieving only one working out of three assembled because of dry joints. With hindsight, a bit of flux probably would have been a good idea.
 
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