Covers: North Dakota, South Dakota, Nebraska, Kansas, Minesota, Iowa, Missouri, Wisconsin, Illinois, Michigan, Indiana and Ohio
Hello everyone. I am in need of a Commodore 1541 logic board for the drives with the Neutronics drive mechanism. I have heard the Neutronics and Alps devices are interchangeable, and that they are not. I am new to the drives and am looking to replace one I tried to repair and just made worse. I am willing to pay for the item and shipping.
NLN, and I am a moron. Wires can be removed and mods redone, and for a new 6502, I can reverse my damage, so I think I have this, thank you.
NLN? This some kinda 1984 Nu-speak? Nine laughing ninjas? Is this what the kids are saying now?
Acronyms will be our downfall?
I take it your 1541 board is not working? Have you tried todo a repair? I have repaired alot of these. If you are unfamiliar with electronics repair there are still a bunch of things you can check on socketed chips if you have a working 1541 drive.
On all the 1541's I have had fail the ROM IC seems to be pretty common. The 6502 cpu not as common but right there as well. Second most common is the TTL 74 logic chips which can be desoldered and checked on a minipro programmer (about $30 device for programming roms and checking TTL logic chips)
@VERAULT No Longer Needed.
I have a box of 1541 PCBs... if you decide you do need one, Robert. Just post a pic of the one you need.
What are your symptoms? The newtronics drives are pretty notorious for the head going open on them.
My 6502 gets hot to the point I nearly gave myself a first degree burn from brushing my forearm against it. I tried to replace a faulty power supple in one I got as not working for parts (the power supply got even hotter) and I think I may have accidently bridged the 5 and 12 volt lines in the mod I found online to use a modern supply, but I found a power supply working from back in the day and am going to put that in and replace the voltage regulators and a new working 6502 to see if that works. If it is just the 6502 I may be fine and I am wrong about my work, great. Otherwise I may have fried more than just the processor and it would be cheaper to just replace the entire board if I can find a working one.
The drive mechanism itself works fine (light goes on and then off) but all tests within BASIC fail, hopefully just due to the processor.
I have a 1541 parts board, if you need replacement chips or parts for a 1541 I can send you the parts board.
I also have a functional 1541 that I can part with.
if He isnt interested I can surely use a spare 1541 board.
You may be lucky and it is just the 6502 CPU.
On the other hand, if you have fed the logic board with more than +5V - well, how lucky do you feel?
I had some luck with a friends audio quadrophonic decoder. The internal 5V voltage regulator had gone short circuit, so I replaced it for another one (having first broken the bad news to my friend that the patient may not survive the operation); but everything worked fine!
In my experience, these things rarely have a happy ending - but always worth a try...
Dave
You may be lucky and it is just the 6502 CPU.
On the other hand, if you have fed the logic board with more than +5V - well, how lucky do you feel?
I had some luck with a friends audio quadrophonic decoder. The internal 5V voltage regulator had gone short circuit, so I replaced it for another one (having first broken the bad news to my friend that the patient may not survive the operation); but everything worked fine!
In my experience, these things rarely have a happy ending - but always worth a try...
Dave
I am hoping it is just the 6502. And I feel better today that it might be. I had a C64 I was restoring and got the PLA replacement in, and when I turned it on I got a lack screen. I let it sit while checking voltages (which we good) and when doing a touch test, the VIC was just as hot on that board as the 6502 was on this logic board, so my hypothesis that I shorted it based on the temp of the chip (Never had them get hot enough to actually burn me like that, but two in such a short span, which crappy luck, is an indicator that my changes may be good) may have been a incorrect hypothesis..
None of the other chips on the 1541 board got hot at all, so I feel that is this all that it is. If when my new one comes in it is not resolved like I said I will likely need a new board and have had offers, I just feel dumb because I was sitting here looking at my board and the fact the chips were in sockets and I can just undo the change I made didn't click until a day after I posted the wanted add.
@VERAULT No Longer Needed.
I have a box of 1541 PCBs... if you decide you do need one, Robert. Just post a pic of the one you need.
I don’t suppose you still have these PCBs? I could use one, I think my PCB (and/or a chip or two on it) is kakked.
I don’t suppose you still have these PCBs? I could use one, I think my PCB (and/or a chip or two on it) is kakked.
Well he never offered me one so good luck with that.....
He was a brand new member who spent a few months on the board and never logged in again.
Welcome aboard a
lpsaficionado. I hope you stay and contribute.. Lots of good folks here.
D’oh. Ah well. Thank you for the welcome!
I don’t suppose you still have these PCBs? I could use one, I think my PCB (and/or a chip or two on it) is kakked.
I do.
