1541 (short board) faulty

ViperSan · Post by **ViperSan** » Fri May 27, 2005 9:27 am

I wonder if any of you technical drive experts could provide any extra help or suggestions ..
I have two drives
The first is a 1540 (long pcb) which has had UAB 5 replaced with a copied 1541 ROM
and the 2nd is a genuine 1541 (short pcb) which has gone faulty..

The 1540 drive is being used to supply donor chips to pin down the fault on the 1541

The fault is as follows ..
When drive powered up, red LED stays on and spindle motor runs
continuously.

Using Carlsens excellent web pages as reference I have tried the following chips by substitution ...
UA1, UB4, UC2, UC4, UC6, UC7, UD3, and UD5.
.fitting IC bases on both pcb's as each chip is substituted ..

Sadly the fault remains ...
so any further help or suggestions would be most welcome.

rgds 2 all
VS

Boray · Post by **Boray** » Sun May 29, 2005 4:30 am

I would rather like a working 1540 than a 1541!!! The 1541 is so very common and cheap. The 1540 is a rare item!

/Anders

ViperSan · Post by **ViperSan** » Sun May 29, 2005 8:23 am

Hi Boray ...
I totally agree ..
Sadly I dont have the origional 1540 rom ..which went faulty many years ago ...hence the substituted 1541 clone rom ..
I have no intemtions of using the chips from the 1540 as a permanent fix for the later 1541 ..
...just borrowing them as a means to try and fix both drives

btw ..
put in a successful bid on a VIC20 on ebay UK
Not too dissapointed with the result though haven't actually received it yet..
Its an origional 2 pin AC psu type and has 6 game carts with the package ..
Nothing rare ...but at £20 plus postage a good deal non the less.

rgds
VS

Schema · Post by **Schema** » Sun May 29, 2005 2:42 pm

ViperSan wrote:Sadly I dont have the origional 1540 rom ..which went faulty many years ago ...hence the substituted 1541 clone rom ..

You can make a 1540 ROM quite easily - I made one and put it in my VIC-1541, so I can at least pretend I have a 1540

You need a Motorola 68764 or an adaptor board like this one.

http://people.freenet.de/x1541/hardware/2364.html

ViperSan · Post by **ViperSan** » Mon May 30, 2005 10:42 am

Thanks Schema ...
very interesting site indeed .
I may well try and reverse my 1540 at some point ...but need to get this 1541 up and running first.
I have my eye open for a scrapper on ebay

rgds
VS

Schema · Post by **Schema** » Mon May 30, 2005 12:07 pm

If you can't find a 1541 on eBay, TPUG has dozens, including several "scrappers", for sale. Email them for cost and shipping.

http://www.icomm.ca/tpug/contact.html