Re: CBM 1541 drive faults

2015-12-14 Thread Ethan Dicks
On Mon, Dec 14, 2015 at 6:32 PM, dwight wrote: > Do remember when ordering 2114's that these are all NOS units > and just about as likely to be bad as the ones in your unit. Too true. NOS doesn't mean it's working. > I don't know of any surplus place that has the ability to test them. Or the i

Re: CBM 1541 drive faults

2015-12-14 Thread drlegendre .
If you need 6522 chip(s) please contact me off-list - I have more than I need, would be happy to pass one along to a needy drive.. On Mon, Dec 14, 2015 at 5:32 PM, dwight wrote: > > Do remember when ordering 2114's that these are all NOS units > and just about as likely to be bad as the ones in

Re: CBM 1541 drive faults

2015-12-14 Thread dwight
Do remember when ordering 2114's that these are all NOS units and just about as likely to be bad as the ones in your unit. I don't know of any surplus place that has the ability to test them. Most any of the places that I've dealt with will replace bad ones but if dealing by mail order, it may not

RE: CBM 1541 drive faults

2015-12-14 Thread Alexandre Souza
They can be easily replaced with newer chips. But any work with it should make you think about building a sd2iec hehehehe (I gotta build one for me...) Enviado do meu Tele-Movel Em 14/12/2015 16:09, "tony duell" escreveu: > > > > I don't think any of the single-disk CBM drives used 2114s (but I

RE: CBM 1541 drive faults

2015-12-14 Thread tony duell
> > I don't think any of the single-disk CBM drives used 2114s (but I > agree - those are favorite suspects when present). I'm pretty sure > all the units I've worked on have 6116-type 2K SRAMs or perhaps 6264s. > I'd have to go back and check parts lists, but the older dual-drive > units might h

Re: CBM 1541 drive faults

2015-12-14 Thread Ethan Dicks
On Sun, Dec 13, 2015 at 10:22 AM, tony duell wrote: >> >> I've done the obvious, reseating socketed ICs, checking the +12V and +5 >> rails, and checking the on-board CPU reset line. Does anyone have any tips >> for what's best to try next? > > Didn't at least some versions use 2114 RAM chips? If s

Re: CBM 1541 drive faults

2015-12-13 Thread Jules Richardson
On 12/13/2015 12:42 PM, Alexandre Souza wrote: Had lots of 6522 and ROM failures here. I'd begin with rom replacement Yeah, I did some swapping around. It seems that one faulty drive has ROM problems, and the other has both a ROM fault *and* a dead 6522 in UC2. cheers Jules

RE: CBM 1541 drive faults

2015-12-13 Thread Alexandre Souza
Had lots of 6522 and ROM failures here. I'd begin with rom replacement Enviado do meu Tele-Movel Em 13/12/2015 16:34, "tony duell" escreveu: > > > > Yes, I've certainly seen that on the schematics, and was considering them > > as a likely failure too - after opening cases though, my drives all s

RE: CBM 1541 drive faults

2015-12-13 Thread tony duell
> > Yes, I've certainly seen that on the schematics, and was considering them > as a likely failure too - after opening cases though, my drives all seem to > have a single larger SRAM (even the Rev A board, so that's presumably "Rev > A of the type that doesn't use 2114's" :-) Yes, later versions

Re: CBM 1541 drive faults

2015-12-13 Thread Jules Richardson
On 12/13/2015 09:22 AM, tony duell wrote: I've done the obvious, reseating socketed ICs, checking the +12V and +5 rails, and checking the on-board CPU reset line. Does anyone have any tips for what's best to try next? Didn't at least some versions use 2114 RAM chips? If so, then check/change t

Re: CBM 1541 drive faults

2015-12-13 Thread Gene Buckle
On 12/13/2015 7:22 AM, tony duell wrote: I've done the obvious, reseating socketed ICs, checking the +12V and +5 rails, and checking the on-board CPU reset line. Does anyone have any tips for what's best to try next? Didn't at least some versions use 2114 RAM chips? If so, then check/change th

Re: CBM 1541 drive faults

2015-12-13 Thread Jules Richardson
On 12/12/2015 08:27 PM, Mike van Bokhoven wrote: Locked on LEDs and spindle motor would suggest VIA to me, though it's been many years since I've looked at one. First thing I'd check is that there's activity on the address/data buses. I don't have a lot of test gear, but I suppose poking at A0

RE: CBM 1541 drive faults

2015-12-13 Thread tony duell
> > I've done the obvious, reseating socketed ICs, checking the +12V and +5 > rails, and checking the on-board CPU reset line. Does anyone have any tips > for what's best to try next? Didn't at least some versions use 2114 RAM chips? If so, then check/change those first -tony

Re: CBM 1541 drive faults

2015-12-12 Thread Mike van Bokhoven
On 13/12/2015 2:01 p.m., Jules Richardson wrote: I have four 1541's now, two of which seem to init OK, and two of which sit there with the drive spindle constantly spinning and the access LEDs lit, the latter behavior which I believe indicates a multitude of possible microcontroller-related fau

CBM 1541 drive faults

2015-12-12 Thread Jules Richardson
I have four 1541's now, two of which seem to init OK, and two of which sit there with the drive spindle constantly spinning and the access LEDs lit, the latter behavior which I believe indicates a multitude of possible microcontroller-related faults... I've done the obvious, reseating socket