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Products => Test Equipment => Topic started by: TMA-1 on December 15, 2024, 06:04:10 am

Title: Willem EPROM Burner Stopped Working
Post by: TMA-1 on December 15, 2024, 06:04:10 am

About a dozen years ago I bought a Willem EPROM Programmer PCB50 Clone.  It worked very well for me at the time, though having to use a Windows XP PC to run the software for it is a bit of a hassle.

Yesterday I tried to use it for the first time in a couple of years, and ran into problems.  (Yes, I still have a desktop that can boot into Windows XP.)

The three status lights are all fine until the programmer software loads up.  As soon as the software initializes, the VCC & VPP lights go out, and there is no voltage there.  (Needless to say any attempted operation fails at that point.)

The power lights stay out, unless and until I reboot the PC; when the PC POSTs, those lights come back on.  Clearly the programmer's software is triggering something bad with the parallel port, but what?

I have tried:

• checking my DIP switches and jumpers about two dozen times;
• using either USB or a DC wall-wart as supplementary power;
• re-capping the Willem board;
• checking the 7805 (it's fine);
• every available setting of BIOS parameters related to the parallel port (defaulting to LPT1, ECP type);
• updating the PCB50 software to the latest;
• updating the parallel port driver, but "best driver already installed".

Anyone have a clue what I'm missing?  Is it time to give up on this vintage burner?

Title: Re: Willem EPROM Burner Stopped Working
Post by: Messtechniker on December 15, 2024, 07:16:24 am

How about checking the voltages present at the transistors. Might give a clue.

Title: Re: Willem EPROM Burner Stopped Working
Post by: pcprogrammer on December 15, 2024, 07:49:07 am

Or the parallel port of the PC is the culprit.

Do you have a scope or simple logic analyzer? If so measure what is going on on the parallel port signals.

Title: Re: Willem EPROM Burner Stopped Working
Post by: TMA-1 on December 15, 2024, 08:10:03 pm

Worthy suggestions both, but it occurred to me that I have another old XP laptop, so I tried that experiment first.

It works.

So the conclusion is, I have a parallel port on my desktop that is somehow defective.  The motherboard is probably right about the correct age to suffer from Bad Caps Disease, too.  In any case the Willem is fine, and I'm back in business.  Thanks all.

Title: Re: Willem EPROM Burner Stopped Working
Post by: optotester on December 16, 2024, 07:57:28 am

Probably not what you want to hear but CH341/CH347 costs less than 10€ and have greater compatibility now.
Still, if you are able to fix it, you can run it under more recent OS: https://www.jonathandupre.fr/articles/24-logiciel-scripts/166-programmateur-willem-pcb5-0c-windows-64-bits/ (https://www.jonathandupre.fr/articles/24-logiciel-scripts/166-programmateur-willem-pcb5-0c-windows-64-bits/) (in French)