Can't duplicate any disk
#21
Here is a better picture where we can see that both chips look ok.

What you were mentioning in the red circle is the TI logo !! Smile

So again, write gate is stuck high when writing.

Pitou!


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#22
More pictures through the magnifying glass...

Again, both chips are ok.

I also notice a solder bridge under the board between 2 pins of IEC connector. Is that expected?

Pitou!


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#23
Well, either your cable is shorted to +5v, the drive is bad and shorting the write gate to +5v, or one of the two buffer chips is bad. How do you know for sure that the write gate is not changing states? What pin are you looking at?

Your screen shot of the flux shows that something is being written.

No, the IEC connector pins shouldn't be bridged. There is no support for the IEC connector, so that is not tested. You can just desolder the bridge or leave it and I will do that if you have to send your board back.

Do you have another cable and another drive to try?
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#24
Jim, please read carefully,

From my very first post:


Quote:- Tried 2 different ribbon cable.
- All drive were powered by external PS. Tried 2 different Power supply.
- Tried 3 different PC 1.44 floppy drives


All those 3 drives write fine in a PC using windows AND the SAME ribbon cables
Tried 2 different cables.


Quote: How do you know for sure that the write gate is not changing states? What pin are you looking at?

Again in my previous post:

Quote:I took my scope and looked at pins 22 (Write data)  and 24 (Write Gate).

Pin 22 looks fine, I see the signal, however pin 24 (Wgate) is always High


So I looked at pin 24.


Yes I can desolder the bridge, will it help?

Pitou!
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#25
No, de-soldering that bridge won't make any difference.  Those pins are connected to the PIC as open-collector outputs.

Return the board and I can look at it.  If the write gate is not going low, then DUEY is destroyed, the cable is bad, or the drive is bad.  The board worked when it left here.  I offer a lifetime warranty on all of my electronics, so just return it and I will replace it.
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#26
ok what is the return shipping address?
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#27
See here:

http://www.cbmstuff.com/contact.htm
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